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Abstracts

Lutein: 50 Research Abstracts

Stroke

1. Free Radic Res. 2002 Mar;36(3):265-8.

Plasma carotenoid and malondialdehyde levels in ischemic stroke patients: relationship to early outcome.

Polidori MC, Cherubini A, Stahl W, Senin U, Sies H, Mecocci P.

Institute of Physiological Chemistry I, Heinrich-Heine University, Dusseldorf, Germany. polidori@uni-duesseldorf.de

An association between ischemic stroke and increased oxidative stress has been suggested from animal studies. However, there is a lack of evidence with respect to this association in humans. Here, the time course of plasma levels of six carotenoids, which are lipophilic micronutrients with antioxidant properties, as well as of malondialdehyde (MDA), a marker of lipid peroxidation, was followed in ischemic stroke patients. Plasma levels of lutein, zeaxanthin, beta-cryptoxanthin, lycopene, alpha- and beta-carotene, as well as MDA were measured by high-performance liquid chromatography in 28 subjects (19 men and nine women aged 76.9+/-8.7 years) with an acute ischemic stroke of recent onset (<24h) on admission, after 6 and 24 h, and on days 3, 5, and 7. Carotenoid and MDA levels in patients on admission were compared with those of age- and sex-matched controls. Plasma levels of lutein, lycopene, alpha- and beta-carotene were significantly lower and levels of MDA were significantly higher in patients in comparison with controls. Significantly higher levels of MDA and lower levels of lutein were found in patients with a poor early-outcome (functional decline) after ischemic stroke as compared to patients who remained functionally stable. These findings suggest that the majority of plasma carotenoids are lowered immediately after an ischemic stroke, perhaps as a result of increased oxidative stress, as indicated by a concomitant rise in MDA concentrations. Among the carotenoids, only lutein plasma changes are associated with a poor early-outcome.

CHD

2. Med J Aust. 2003 May 19;178(10):495-500.

Inflammation and vascular endothelial activation in an Aboriginal population: relationships to coronary disease risk factors and nutritional markers.

Rowley K, Walker KZ, Cohen J, Jenkins AJ, O'Neal D, Su Q, Best JD, O'Dea K.

University of Melbourne, Department of Medicine, St Vincent's Hospital, 4th Floor, Clinical Sciences Building, Fitzroy, Victoria 3065, Australia. kevinr@medstv.unimelb.edu.au

OBJECTIVE: To describe the levels of inflammation and vascular endothelial activation in an Aboriginal community, and the relationship of these factors to coronary heart disease (CHD) risk factors and markers of nutritional quality. DESIGN AND PARTICIPANTS: A cross-sectional survey of 95 women and 76 men participating in a chronic-disease prevention program. SETTING: A remote Aboriginal community in Western Australia in 1996. MAIN OUTCOME MEASURES: Concentrations of markers of inflammation (C-reactive protein [CRP]) and vascular endothelial activation (soluble E-selectin [sE-selectin]); presence of metabolic syndrome; concentrations of diet-derived antioxidants. RESULTS: Participants exhibited very high plasma concentrations of CRP (mean, 5.4 mg/L; 95% CI, 4.6-6.3 mg/L) and sE-selectin (mean, 119 ng/mL; 95% CI, 111-128 ng/mL). Both CRP and sE-selectin concentrations were significantly higher in the presence of the metabolic syndrome. There were significant inverse linear relationships between concentrations of CRP and plasma concentrations of the antioxidants lycopene, beta-carotene, cryptoxanthin and retinol. Even stronger inverse associations were evident between concentrations of sE-selectin and lycopene, beta-carotene, cryptoxanthin and lutein. CONCLUSIONS: Vascular inflammation and endothelial activation may be important mediators of elevated CHD risk in Aboriginal people. Inadequate nutrition and physical inactivity may contribute to this process.

Antioxidant

3. Clin Pharmacokinet. 2003;42(5):437-59.

Clinical pharmacokinetics of antioxidants and their impact on systemic oxidative stress.

Schwedhelm E, Maas R, Troost R, Boger RH.

Institute of Experimental and Clinical Pharmacology, Clinical Pharmacology Unit, University Hospital of Hamburg-Eppendorf, Hamburg, Germany. schwedhelm@uke-hamburg.de

Dietary antioxidants play a major role in maintaining the homeostasis of the oxidative balance. They are believed to protect humans from disease and aging. Vitamin C (ascorbic acid), vitamin E (tocopherol), beta-carotene and other micronutrients such as carotenoids, polyphenols and selenium have been evaluated as antioxidant constituents in the human diet. This article addresses data provided from clinical trials, highlighting the clinical pharmacokinetics of vitamin C, vitamin E, beta-carotene, lycopene, lutein, quercetin, rutin, catechins and selenium. The bioavailability of vitamin C is dose-dependent. Saturation of transport occurs with dosages of 200-400 mg/day. Vitamin C is not protein-bound and is eliminated with an elimination half-life (t((1/2))) of 10 hours. In Western populations plasma vitamin C concentrations range from 54-91 micro mol/L. Serum alpha- and gamma-tocopherol range from 21 micro mol/L (North America) to 27 micro mol/L (Europe) and from 3.1 micro mol/L to 1.5 micro mol/L, respectively. alpha-Tocopherol is the most abundant tocopherol in human tissue. The bioavailability of all-rac-alpha-tocopherol is estimated to be 50% of R,R,R-alpha-tocopherol. The hepatic alpha-tocopherol transfer protein (alpha-TTP) together with the tocopherol-associated proteins (TAP) are responsbile for the endogenous accumulation of natural alpha-tocopherol. Elimination of alpha-tocopherol takes several days with a t((1/2)) of 81 and 73 hours for R,R,R-alpha-tocopherol and all-rac-alpha-tocopherol, respectively. The t((1/2)) of tocotrienols is short, ranging from 3.8-4.4 hours for gamma- and alpha-tocotrienol, respectively. gamma-Tocopherol is degraded to 2, 7, 8-trimethyl-2-(beta-carboxyl)-6-hyrdoxychroman by the liver prior to renal elimination. Blood serum carotenoids in Western populations range from 0.28-0.52 micro mol/L for beta-carotene, from 0.2-0.28 for lutein, and from 0.29-0.60 for lycopene. All-trans-carotenoids have a better bioavailability than the 9-cis-forms. Elimination of carotenoids takes several days with a t((1/2)) of 5-7 and 2-3 days for beta-carotene and lycopene, respectively. The bioconversion of beta-carotene to retinal is dose-dependent, and ranges between 27% and 2% for a 6 and 126mg dose, respectively. Several oxidised metabolites of carotenoids are known. Flavonols such as quercetin glycosides and rutin are predominantly absorbed as aglycones, bound to plasma proteins and subsequently conjugated to glucuronide, sulfate, and methyl moieties. The t((1/2)) ranges from 12-19 hours. The bioavailabillity of catechins is low and they are eliminated with a t((1/2)) of 2-4 hours. Catechins are degraded to several gamma-valerolactone derivatives and phase II conjugates have also been identified. Only limited clinical pharmacokinetic data for other polyphenols such as resveratrol have been reported to date.

4. Nutr Cancer. 2002;43(2):202-13.

Increased cellular carotenoid levels reduce the persistence of DNA single-strand breaks after oxidative challenge.

Astley SB, Elliott RM, Archer DB, Southon S.

Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK. sian.astley@bbsrc.ac.uk

Dietary antioxidants, such as the carotenoids, may protect DNA from oxidative damage. This has been proposed to explain the epidemiological association between higher consumption of fruits and vegetables, which are rich in antioxidants, and lower incidence of cancer. However, this remains to be demonstrated conclusively. The effects of carotenoid supplementation on 1) baseline DNA damage, 2) susceptibility of cellular DNA to oxidative attack, and 3) DNA repair were measured in the human lymphocyte cell line Molt-17. Baseline DNA damage, susceptibility to oxidant attack (100 mumol/l H2O2 for 5 min at 4 degrees C), and disappearance of DNA single-strand breaks (SSB) after oxidative challenge were monitored by single-cell gel electrophoresis. DNA repair patch synthesis activity in cell extracts was determined using assays that measure nucleotide incorporation during repair of oxidative lesions in template DNA. Unlike single-cell gel electrophoresis, the parameters measured with these assays are not dependent on strand break religation. There was no evidence that beta-carotene, lutein, or beta-cryptoxanthin supplementation protected cellular DNA from oxidation under basal conditions or after oxidative challenge. However, only carotenoid-supplemented cells exhibited a significant decrease in numbers of SSB over a 2-h period after treatment with H2O2. Carotenoid supplementation did not provoke any detectable change in repair patch synthesis activity. We conclude that supplementation with carotenoids at 8 mumol/l does not provide significant antioxidant protection for DNA in Molt-17 lymphocytes but may enhance recovery of cells from oxidative challenge, as measured by loss of SSB. We argue that these data are most consistent with carotenoids acting to enhance DNA strand break repair.

5. Eur J Nutr. 2002 Jun;41(3):95-100.

Spinach and tomato consumption increases lymphocyte DNA resistance to oxidative stress but this is not related to cell carotenoid concentrations.

Porrini M, Riso P, Oriani G.

Department of Food Science and Technology, Division of Human Nutrition, University of Milan, Via Celoria 2, 20133 Milano, Italy. marisa.porrini@unimi.it

BACKGROUND: The increased consumption of fruit and vegetables has been linked to protection against different chronic diseases, but the dietary constituents responsible for this association have not been clearly identified. AIM OF THE STUDY: We evaluated the effect of spinach and spinach+tomato puree consumption on cell DNA resistance to an oxidative stress. METHODS: To this aim, in a dietary controlled intervention study, 9 healthy female volunteers consumed a basal diet low in carotenoids (< 600 microg/day) enriched with daily portions (150 g) of spinach (providing about 9 mg lutein, 0.6 mg zeaxanthin, 4 mg beta-carotene) for 3 weeks (from day 0 to day 21) followed by a 2 week wash-out period (basal diet) and finally another 3 weeks (from day 35 to day 56) of diet enriched with daily portions of spinach (150 g) + tomato puree (25 g, providing about 7 mg lycopene, 0.3 mg beta-carotene). At the beginning and the end of each period of vegetable intake, blood samples were collected for lymphocyte separation. Carotenoid concentrations of lymphocytes were determined by HPLC and DNA damage was evaluated by the comet assay following an ex vivo treatment with H(2)O(2). RESULTS: During the first period of spinach consumption, lymphocyte lutein concentration did not increase significantly (from 1.6 to 2.2 micromol/10(12) cells) while lycopene and beta-carotene concentrations decreased significantly (from 1.0 to 0.1 micromol/10(12) cells, P < 0.001, and from 2.2 to 1.2 micromol/10(12) cells, P < 0.05, respectively). Lutein and lycopene concentrations increased after spinach+tomato puree consumption (from 1.2 to 3.5 micromol/10(12) cells, P < 0.01, and from 0.1 to 0.7 micromol/10(12) cells, P < 0.05, respectively). The increase may be attributed to the addition of tomato puree to spinach; however, the different concentrations of carotenoids in lymphocytes registered at the beginning of the two intervention periods may have affected the results. DNA resistance to H(2)O(2) insult increased significantly after both the enriched diets (P < 0.01); however, no "additive effect" was seen after spinach + tomato puree consumption. In the spinach + tomato intervention period an inverse correlation was observed between lymphocyte lycopene concentration and DNA damage, but this seems not able to explain the protection observed. CONCLUSIONS: The consumption of carotenoid-rich foods even for a short period of time gives protection against oxidative stress. The results obtained seem to suggest that this protective role is not specifically related to carotenoids. However they may contribute together with other substances present in vegetables to lymphocyte resistance to oxidative damage.

6. Wilderness Environ Med. 2002 Summer;13(2):94-105.

Oxidative stress in humans training in a cold, moderate altitude environment and their response to a phytochemical antioxidant supplement.

Schmidt MC, Askew EW, Roberts DE, Prior RL, Ensign WY Jr, Hesslink RE Jr.

University of Utah, Salt Lake City 84112, USA.

OBJECTIVE: This study examined the effectiveness of an antioxidant mixture containing vitamin E, beta-carotene, ascorbic acid, selenium, alpha-lipoic acid, N-acetyl 1-cysteine, catechin, lutein, and lycopene to reduce oxidative stress in US Marines undergoing 24 days of cold-weather field training at a moderate altitude. METHODS: Forty physically active male volunteers (ages 18-40) were randomly assigned to a treatment (antioxidant) group (n = 21) or a control (placebo) group (n = 19). Breath pentane (BP), serum lipid hydroperoxides (LPO), urine malondialdehyde (MDA), urine 8-hydroxy deoxyguanosine (8-OHdG), ferric-reducing ability of plasma (FRAP), and serum and urine oxygen radical absorption capacity (ORAC) were measured as indicators of oxidative stress and antioxidant status. Urine was sampled at days 0, 12, and 24. Serum and breath were sampled on days 0 and 24. RESULTS: Both groups exhibited increased levels of oxidative stress after 24 days of field training, as indicated by an increased LPO, pentane, and 8-OHdG. There was no significant difference between the treatment and placebo groups at day 24; however, there was some indication that test subjects with initially low antioxidant capacity (ORAC) may have benefited from the antioxidant supplement. CONCLUSIONS: An increased level of oxidative stress was associated with high levels of physical exertion of training in a cold environment at moderate altitude. The antioxidant mixture tested did not attenuate the mean oxidative stress levels in the entire group of test subjects, but it may have reduced the oxidative stress of some individuals with low initial antioxidant status.

7. Lancet. 2002 Jun 8;359(9322):1969-74.

Comment in: Lancet. 2002 Nov 30;360(9347):1785-6; author reply 1786. Lancet. 2002 Nov 30;360(9347):1786.

Effects of fruit and vegetable consumption on plasma antioxidant concentrations and blood pressure: a randomised controlled trial.

John JH, Ziebland S, Yudkin P, Roe LS, Neil HA; Oxford Fruit and Vegetable Study Group.

Division of Public Health and Primary Health Care, Department of Primary Health Care, University of Oxford, Oxford, UK

BACKGROUND: High dietary intakes of fruit and vegetables are associated with reduced risks of cancer and cardiovascular disease. Short-term intensive dietary interventions in selected populations increase fruit and vegetable intake, raise plasma antioxidant concentrations, and lower blood pressure, but long-term effects of interventions in the general population are not certain. We assessed the effect of an intervention to increase fruit and vegetable consumption on plasma concentrations of antioxidant vitamins, daily fruit and vegetable intake, and blood pressure. METHODS: We undertook a 6-month, randomised, controlled trial of a brief negotiation method to encourage an increase in consumption of fruit and vegetables to at least five daily portions. We included 690 healthy participants aged 25-64 years recruited from a primary-care health centre. FINDINGS: Plasma concentrations of alpha-carotene, beta-carotene, lutein, beta-cryptoxanthin, and ascorbic acid increased by more in the intervention group than in controls (significance of between-group differences ranged from p=0.032 to 0.0002). Groups did not differ for changes in lycopene, retinol, alpha-tocopherol, gamma-tocopherol, or total cholesterol concentrations. Self-reported fruit and vegetable intake increased by a mean 1.4 (SD 1.7) portions in the intervention group and by 0.1 (1.3) portion in the control group (between-group difference=1.4, 95% CI 1.2-1.6; p<0.0001). Systolic blood pressure fell more in the intervention group than in controls (difference=4.0 mm Hg, 2.0-6.0; p<0.0001), as did diastolic blood pressure (1.5 mm Hg, 0.2-2.7; p=0.02). INTERPRETATION: The effects of the intervention on fruit and vegetable consumption, plasma antioxidants, and blood pressure would be expected to reduce cardiovascular disease in the general population.

8. Cancer Epidemiol Biomarkers Prev. 2000 Apr;9(4):421-5.

Plasma xanthophyll carotenoids correlate inversely with indices of oxidative DNA damage and lipid peroxidation.

Haegele AD, Gillette C, O'Neill C, Wolfe P, Heimendinger J, Sedlacek S, Thompson HJ.

AMC Cancer Research Center, Denver, Colorado 80214, USA. haegelea@amc.org

Post hoc analysis of data obtained from a study designed to modulate oxidative damage by dietary intervention revealed consistently strong inverse correlations between plasma xanthophyll carotenoids and oxidative damage indices. Thirty-seven women participated in a 14-day dietary intervention that increased mean vegetable and fruit (VF) consumption to approximately 12 servings/day. An additional 10 subjects participated in an intervention that limited VF consumption to less than four servings per day. 8-Hydroxy-2'-deoxyguanosine (8-OHdG) in DNA isolated from peripheral lymphocytes and 8-OHdG excreted in urine were measured as indices of oxidative DNA damage. Lipid peroxidation was assessed by measuring 8-epiprostaglandin F2alpha (8-EPG) in urine. Plasma levels of selected carotenoids were also determined, with the intention of using a-carotene as a biochemical index of VF consumption. Urinary 8-OHdG and 8-EPG were measured by ELISA, and plasma carotenoids were measured by high performance liquid chromatography. Lymphocyte 8-OHdG was measured by reverse phase high performance liquid chromatography with electrochemical detection. We observed that the structurally related xanthophyll carotenoids, lutein and beta-cryptoxanthin, which occur in dissimilar botanical families, were consistently inversely associated with these oxidative indices. Statistically significant inverse correlations were observed between plasma lutein and/or beta-cryptoxanthin levels and lymphocyte 8-OHdG and urinary 8-EPG. Moreover, an inverse correlation was observed between change in plasma xanthophylls and change in lymphocyte 8-OHdG concentration that occurred during the course of the study. These data lead us to hypothesize that lutein and beta-cryptoxanthin serve as markers for the antioxidant milieu provided by plants from which they are derived. Whether these carotenoids are directly responsible for the observed antioxidant phenomena merits further investigation.

Alzheimer’s

9. J Alzheimers Dis. 2002 Dec;4(6):517-22.

Plasma susceptibility to free radical-induced antioxidant consumption and lipid peroxidation is increased in very old subjects with Alzheimer disease.

Polidori MC, Mecocci P.

Institute of Physiological Chemistry I, Heinrich-Heine University, Dusseldorf, Germany. polidori@uni-duesseldorf.de

Oxidative stress is believed to play a major role in the pathogenesis of Alzheimer disease (AD). Plasma concentrations of vitamins C, A and E, of uric acid, thiols and carotenoids were lower and of malondialdehyde (MDA) higher in 35 AD patients (85.9 +/- 5.5 y) compared to 40 controls 85.5 +/- 4.4 y). Differences were significant for vitamin C, vitamin E, lutein, lycopene, alpha-carotene and MDA (p < 0.001). Plasma exposed to peroxyl radicals showed a rate of antioxidant consumption and of MDA production higher in AD patients than in controls. AD in advanced age is accompanied by a poor plasma antioxidant status and increased plasma lipid peroxidation, as well as by a low resistance to peroxyl radical exposure.

Colorectal adenomas

10. Clin Nutr. 2003 Feb;22(1):65-70.

Carotenoids are decreased in biopsies from colorectal adenomas.

Muhlhofer A, Buhler-Ritter B, Frank J, Zoller WG, Merkle P, Bosse A, Heinrich F, Biesalski HK.

Center of Internal Medicine, University of Hohenheim, Fruwirthstrasse 12, D-70593 Stuttgart, Germany

A lower intake of carotenoids is associated with an increased risk of colorectal cancer. In order to take advantage of the chemopreventive properties of carotenoids, it is necessary to determine carotenoid concentration at the target tissue. As early stages in the adenoma-carcinoma sequence of colorectal cancer might be susceptible to chemoprevention, we sought to determine carotenoid concentrations in biopsies from colorectal adenomas. METHODS: Biopsies from colorectal adenomas and non-involved mucosa were taken from seven patients. For controls, biopsies were obtained from the ascending and descending colon of patients without polyps (n = 5). Concentration of carotenoids (alpha-, beta-carotene, lutein, lycopene, zeaxanthin, beta-cryptoxanthin) were determined by optimizing gradient HPLC-analysis. Results are expressed as pmol/microg DNA. RESULTS: Except for alpha-carotene, all carotenoids could reliably be detected in all specimens. In control patients carotenoid concentrations were highest in the ascending colon, being followed by the descending colon and non-involved mucosa from polyp-carriers. In colorectal adenomas all carotenoids were significantly reduced as compared to-non-involved mucosa (beta-carotene: 0.37 vs 0.19, P<0.03; lycopene: 0.34 vs 0.21, P<0.06, beta-cryptoxanthin: 0.14 vs 0.09, P<0.03, zeaxanthin: 0.18 vs 0.09, P<0.02; lutein: 0.18 vs 0.13,P <0.02). CONCLUSION: All carotenoids investigated are reduced in colorectal adenomas, suggesting that mucosal carotenoids could serve as biomarkers for predisposition to colorectal cancer. Moreover, anti-tumor activity exerted by carotenoids is limited due to mucosal depletion. We speculate that supplementation of a larger array of carotenoids might be beneficial for patients with colorectal adenoma.

11. Eur J Cancer. 2000 Oct;36(16):2115-9.

Selected micronutrients and colorectal cancer. a case-control study from the canton of Vaud, Switzerland.

Levi F, Pasche C, Lucchini F, La Vecchia C.

Unite d'Epidemiologie du Cancer, Institut Universitaire de Medecine Sociale et Preventive, Bugnon 17, 1005, Lausanne, Switzerland. fabio.levi@insthospvd.ch

The association between dietary intake of various micronutrients and colorectal cancer risk was analysed using data from a case-control study conducted between 1992 and 1997 in the Swiss Canton of Vaud. Cases were 223 subjects (142 (64%) males, 81 (36%) females; median age 63 years) with incident, histologically confirmed colon (n=119; 53%) or rectal (n=104; 47%) cancer, and controls were 491 subjects (211 (43%) males, 280 (57%) females; median age 58 years; range 27-74) admitted to the same university hospital for a wide spectrum of acute non-neoplastic conditions, unrelated to long-term modifications of diet. Dietary habits were investigated using a validated food frequency questionnaire (FFQ). Odds ratios (OR) were obtained after allowance for age, sex, education, smoking, alcohol, body mass index, physical activity, and total energy and fibre intake. No significant association was observed for calcium, retinol, folate, vitamin D or E. The risk of colorectal cancer was directly associated with measures of iron intake (OR=2.43 for the highest tertile, 95% confidence interval (CI): 1.2-5.1) and inversely associated with vitamin C (OR=0.45; 95% CI: 0.3-0.8), and non-significantly with total carotenoids (OR=0.66, 95% CI: 0.4-1.1). Among various individual carotenoids considered, inverse associations were observed for alpha-carotene, beta-carotene and lutein/zeaxanthin. These findings were consistent across the strata of gender and age, and support the hypothesis that selected micronutrients have a favourable effect on colorectal carcinogenesis.

12. Am J Clin Nutr. 2000 Feb;71(2):575-82.

Carotenoids and colon cancer.

Slattery ML, Benson J, Curtin K, Ma KN, Schaeffer D, Potter JD.

University of Utah Medical School, Salt Lake City, USA. mslatter@dfpm.utah.edu

BACKGROUND: Carotenoids have numerous biological properties that may underpin a role for them as chemopreventive agents. However, except for beta-carotene, little is known about how dietary carotenoids are associated with common cancers, including colon cancer. OBJECTIVE: The objective of this study was to evaluate associations between dietary alpha-carotene, beta-carotene, lycopene, lutein, zeaxanthin, and beta-cryptoxanthin and the risk of colon cancer. DESIGN: Data were collected from 1993 case subjects with first primary incident adenocarcinoma of the colon and from 2410 population-based control subjects. Dietary data were collected from a detailed diet-history questionnaire and nutrient values for dietary carotenoids were obtained from the US Department of Agriculture-Nutrition Coordinating Center carotenoid database (1998 updated version). RESULTS: Lutein was inversely associated with colon cancer in both men and women [odds ratio (OR) for upper quintile of intake relative to lowest quintile of intake: 0.83; 95% CI: 0.66, 1.04; P = 0.04 for linear trend]. The greatest inverse association was observed among subjects in whom colon cancer was diagnosed when they were young (OR: 0.66; 95% CI: 0.48, 0.92; P = 0.02 for linear trend) and among those with tumors located in the proximal segment of the colon (OR: 0.65; 95% CI: 0.51, 0.91; P < 0.01 for linear trend). The associations with other carotenoids were unremarkable. CONCLUSION: The major dietary sources of lutein in subjects with colon cancer and in control subjects were spinach, broccoli, lettuce, tomatoes, oranges and orange juice, carrots, celery, and greens. These data suggest that incorporating these foods into the diet may help reduce the risk of developing colon cancer.

UV-induced erythema

13. J Nutr. 2003 Jan;133(1):98-101.

Supplementation with beta-carotene or a similar amount of mixed carotenoids protects humans from UV-induced erythema.

Heinrich U, Gartner C, Wiebusch M, Eichler O, Sies H, Tronnier H, Stahl W.

Institut fur Experimentelle Dermatologie, Universitat Witten-Herdecke, Germany.

Carotenoids are useful oral sun protectants, and supplementation with high doses of beta-carotene protects against UV-induced erythema formation. We compared the erythema-protective effect of beta-carotene (24 mg/d from an algal source) to that of 24 mg/d of a carotenoid mix consisting of the three main dietary carotenoids, beta-carotene, lutein and lycopene (8 mg/d each). In a placebo-controlled, parallel study design, volunteers with skin type II (n = 12 in each group) received beta-carotene, the carotenoid mix or placebo for 12 wk. Carotenoid levels in serum and skin (palm of the hand), as well as erythema intensity before and 24 h after irradiation with a solar light simulator were measured at baseline and after 6 and 12 wk of treatment. Serum beta-carotene concentration increased three- to fourfold (P < 0.001) in the beta-carotene group, whereas in the mixed carotenoid group, the serum concentration of each of the three carotenoids increased one- to threefold (P < 0.001). No changes occurred in the control group. The intake of either beta-carotene or a mixture of carotenoids similarly increased total carotenoids in skin from wk 0 to wk 12. No changes in total carotenoids in skin occurred in the control group. The intensity of erythema 24 h after irradiation was diminished in both groups that received carotenoids and was significantly lower than baseline after 12 wk of supplementation. Long-term supplementation for 12 wk with 24 mg/d of a carotenoid mix supplying similar amounts of beta-carotene, lutein and lycopene ameliorates UV-induced erythema in humans; the effect is comparable to daily treatment with 24 mg of beta-carotene alone.

Macular degeneration/function

14. Ophthalmology. 2003 Jan;110(1):51-60; discussion 61.

Influence of short-term antioxidant supplementation on macular function in age-related maculopathy: a pilot study including electrophysiologic assessment.

Falsini B, Piccardi M, Iarossi G, Fadda A, Merendino E, Valentini P.

Istituto di Oftalmologia, Universita Cattolica del S. Cuore, Rome, Italy.

PURPOSE: To evaluate the influence of short-term antioxidant supplementation on retinal function in age-related maculopathy (ARM) patients by recording focal electroretinograms (FERGs). DESIGN: Nonrandomized, comparative clinical trial. PARTICIPANTS: Thirty patients with early ARM and visual acuity >/=20/30, divided into two groups, similar for age and disease severity: antioxidant group (ARM-A, n = 17) and no treatment group (ARM-NT, n = 13). Eight age-matched normal subjects divided into antioxidant (N-A, n = 4) or no treatment (N-NT, n = 4) groups. METHODS: ARM-A patients and N-A patients had oral supplementation of lutein, 15 mg; vitamin E, 20 mg; and nicotinamide, 18 mg, daily for 180 days, whereas ARM-NT patients and N-NT patients had no dietary supplementation during the same period. Eight of the 17 ARM-A patients took supplementation for an additional 180-day period. In all patients and normal subjects, FERG assessment was performed at the study entry (baseline) and after 180 days. Further testing was performed at 360 days for the eight ARM-A patients taking supplements and for one ARM-A patient who had discontinued supplementation after 180 days. FERGs were recorded in response to a 41-Hz sinusoidally modulated uniform field (93.5% modulation depth) presented to the macular region (18 degrees ) on a light-adapting background. In a subgroup of patients (11 ARM-A and 5 ARM-NT), whose responses had suitable signal-to-noise ratios, FERGs were also recorded at different stimulus modulation depths between 8.25% and 93.5%. MAIN OUTCOME AND MEASURES: Amplitude (in micro V) and phase (in degrees) of the FERG fundamental harmonic component. FERG modulation thresholds, estimated from the value of log modulation depth yielding a criterion response. RESULTS: At 180 days, FERGs of ARM-A patients and N-A patients were increased in amplitude (mean change, 0.11 and 0.15 log micro V, respectively, P </= 0.01) compared with baseline values, whereas no significant changes in FERG amplitudes of ARM-NT patients and N-NT patients were found (mean change, -0.004 and -0.023 log micro V, respectively). In all groups no changes in the FERG phase were found. FERG modulation thresholds decreased with respect to baseline values (mean change, -0.36 log units, P < 0.01) in ARM-A patients, whereas no significant change (mean change, 0.07 log units) in ARM-NT patients was seen. At 360 days, FERGs of ARM-A patients taking supplementation were still increased in amplitude with respect to baseline (P < 0.05) but did not differ from those recorded at 180 days. In the patient who had discontinued supplementation, FERG amplitude decreased from the 180 days value, approaching that recorded at baseline. CONCLUSIONS: Although this study provides no evidence for the long-term benefit of antioxidants in ARM, the results suggest that increasing the level of retinal antioxidants might influence macular function early in the disease process, as well as in normal aging.

15. Acta Ophthalmol Scand. 2002 Aug;80(4):368-71.

Neovascular age-related macular degeneration and its relationship to antioxidant intake.

Snellen EL, Verbeek AL, Van Den Hoogen GW, Cruysberg JR, Hoyng CB.

Department of Epidemiology and Biostatistics, University Medical Centre, Nijmegen, Netherlands.

PURPOSE: Experimental and epidemiological studies suggest that low antioxidant intake may be associated with the occurrence of neovascular age-related macular degeneration (AMD). METHODS: We investigated this hypothesis further with a case-control study involving 72 case and 66 control patients attending the Ophthalmology Department of the University Hospital in Nijmegen. Data were collected by interview on antioxidant intake (i.e. in fruit and vegetables), cigarette smoking, sunlight exposure and familial predisposition. Antioxidant intake was calculated according to the method described in the Framingham Eye Study. Logistic regression analysis was used to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: The prevalence rate of AMD in patients with low antioxidant intake and low lutein intake (dichotomized at the median value) was about twice as high as that in patients with high intake: OR = 1.7, 95% CI (0.8-3.7), and OR = 2.4, 95% CI (1.1-5.1). Further specification of intake data into quartiles of antioxidant intake and lutein/zeaxanthine intake showed a clear dose-response relationship. CONCLUSION: The effect of dietary antioxidants upon macular health warrants preventive studies.

16. Ophthalmologe. 2002 Apr;99(4):270-5.

[Objective determination of optical density of xanthophyll after supplementation of lutein]

[Article in German]

Schweitzer D, Lang GE, Beuermann B, Remsch H, Hammer M, Thamm E, Spraul CW, Lang GK.

Bereich Experimentelle Ophthalmologie, Augenklinik der Friedrich-Schiller-Universitat Jena. Dietrich.Schweitzer@med.uni-jena.de

BACKGROUND: It is thought that a high optical density of xanthophyll has a protective effect against the development of aggregated macular degeneration. The aim of this study was to investigate whether an increase of the optical density of xanthophyll in the macula after a supplementation of lutein can be proven by objective methods. Most methods applied for the determination of the macular pigment require the co-operation of the proband and the ability for foveal fixation. METHOD: Imaging spectrometry and the evaluation of laser scanner images taken at 488 nm will be presented. In contrast to psychophysical methods, both methods are independent of the patients ability for foveal fixation. RESULTS: Even by evaluation of laser scanner images taken as in fluorescence angiography but without inserting the blocking filter, the 2-dimensional distribution of xanthophyll can be determined. In 10 probands taking 6 mg lutein daily over 40 days, an increase of the optical density could be determined at least in some probands. The optical density reached a plateau 30 days after starting the supplementation of lutein. CONCLUSION: The assumed protective effect of xanthophyll against age-related macular degeneration can be influenced by supplementation of lutein under objective control.

17. Exp Eye Res. 2002 Mar;74(3):371-81.

Macular pigment and lutein supplementation in choroideremia.

Duncan JL, Aleman TS, Gardner LM, De Castro E, Marks DA, Emmons JM, Bieber ML, Steinberg JD, Bennett J, Stone EM, MacDonald IM, Cideciyan AV, Maguire MG, Jacobson SG.

Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA 19104, USA.

Choroideremia is an incurable X-linked retinal degeneration caused by mutations in the gene encoding Rab escort protein-1. A group of clinically defined and genotyped patients were studied to determine: (1) the degree of rod and cone dysfunction and structural abnormality in the central retina and the level of macular pigment; and (2) the response of macular pigment and foveal vision to a 6 month trial of supplementation with oral lutein (at 20 mg per day). Rod and cone-mediated function was measured with dark-adapted static perimetry; in vivo retinal structure was determined with optical coherence tomography; and macular pigment optical density was measured with heterochromatic flicker photometry. In this cohort of patients (ages 15-65 years), both rod- and cone-mediated central function declined with age as did central retinal thickness. Macular pigment levels did not differ between patients and male control subjects. Supplementation of oral lutein in a subset of patients led to an increase in serum lutein and macular pigment levels; absolute foveal sensitivity did not change. It is concluded that macular pigment density can be augmented by oral intake of lutein in patients with choroideremia. There was no short-term change in the central vision of the patients on the supplement, but long-term influences of lutein supplementation on disease natural history warrant further study. Copyright 2002 Elsevier Science Ltd.

18. Invest Ophthalmol Vis Sci. 2002 Jan;43(1):47-50.

Macular pigment density is reduced in obese subjects.

Hammond BR Jr, Ciulla TA, Snodderly DM.

Vision Science Laboratory, University of Georgia, Athens, Georgia 30602, USA. bhammond@egon.psy.uga.edu

PURPOSE: Because of the potential protective function of lutein (L) and zeaxanthin (Z) within the retina and lens, a better understanding of factors influencing tissue deposition is needed. The largest fractions of L and Z are stored in adipose tissue. Thus, higher body fat content and body mass index (BMI) may be expected to influence the quantities of L and Z in the retina (measured as macular pigment optical density, MPOD). METHODS: Six hundred eighty subjects were tested. Information on MPOD, body mass index (BMI), body fat percentage (n = 400, using bioelectric impedance), dietary intake (n = 280, using a food frequency questionnaire), and serum carotenoid content (n = 280, using reversed phase high-performance liquid chromatography) was obtained. RESULTS: There was an inverse relationship between MPOD and BMI (n = 680, r = -0.12, P < 0.0008) and between MPOD and body fat percentage (n = 400, r = -0.12, P < 0.01). These relationships were largely driven by data from the subjects with higher BMI (more than 29, 21% less MP) and higher body fat percentage (more than 27%, 16% less MP). Dietary carotenoid intake and serum carotenoid levels were also lower in subjects with higher BMI (n = 280). CONCLUSIONS: Obese subjects tend to have lower retinal L and Z. This reduction may be due to decreased dietary intake of L and Z and/or competition between retina and adipose tissue for uptake of L and Z.

19. Free Radic Biol Med. 2001 Jul 15;31(2):217-25. (Animal study)

Lipofuscin-formation in retinal pigment epithelial cells is reduced by antioxidants.

Sundelin SP, Nilsson SE.

Division of Ophthalmology, Department of Neuroscience and Locomotion, Linkoping University, Linkoping, Sweden. staffan.sudelin@lio.se

The accumulation of lipofuscin by retinal pigment epithelium may be an important feature in the pathogenesis of age-related macular degeneration, suggesting the possibility that this common cause of blindness might be prevented or delayed by antioxidants. In support of this idea, we now report significantly reduced formation of lipofuscin when the antioxidant substances lutein, zeaxanthin, lycopene (carotenoids), or alpha-tocopherol were added to rabbit and bovine (calf) retinal pigment epithelial (RPE) cells exposed to normobaric hyperoxia (40%) and photoreceptor outer segments. Rabbit and calf RPE cells were grown for 2 weeks with addition of one of the test substances every 48 h. The cellular uptake of carotenoids and alpha-tocopherol was assayed by HPLC after 2 weeks. The lipofuscin-content was measured by static fluorometry (rabbit cells) or by image analysis (calf cells). Both rabbit and calf RPE showed similar results with significantly lower amounts of lipofuscin in antioxidant-treated cells. The effect of carotenoids is especially interesting, since the result is not dependent on their protective effect against photo-oxidative reactions. The chain-breaking abilities of these antioxidants in peroxidative reactions of lipid membranes and quenching of free radicals seem to be of importance for inhibition of lipofuscin formation.

20 .Ophthalmology. 2001 Apr;108(4):730-7.

Macular pigment optical density in a midwestern sample.

Ciulla TA, Curran-Celantano J, Cooper DA, Hammond BR Jr, Danis RP, Pratt LM, Riccardi KA, Filloon TG.

Retina Service, Department of Ophthalmology, Indiana University School of Medicine, 702 Rotary Circle, Indianapolis, IN 46260, USA.

OBJECTIVE: To assess the distribution of the macular pigments (MPs) lutein (L) and zeaxanthin (Z) in a healthy sample more representative of the general population than past studies and to determine which dietary factors and personal characteristics might explain the large interindividual differences in the density of these MPs. DESIGN: Prevalence study in a self-selected population. PARTICIPANTS: Two hundred eighty healthy adult volunteers, consisting of 138 men and 142 women, between the ages of 18 and 50 years, recruited from the general population. METHODS: MP optical density was measured psychophysically at 460 nm by use of a 1 degrees test field. Serum was analyzed for carotenoid and vitamin E content with reversed-phase high-performance liquid chromatography. Usual intakes of nutrients over the past year were determined by means of a food frequency questionnaire. MAIN OUTCOME MEASURES: MP optical density. RESULTS: Mean MP optical density measured 0.211 +/- 0.13, which is approximately 40% lower than the average reported in smaller, less representative studies. MP density was 44% lower in the bottom versus the top quintile of serum L and Z concentrations. Similarly, MP density was 33% lower in the bottom compared with the top quintile of L and Z intake. MP density was 19% lower in blue-grey-eyed subjects than in subjects with brown-black irises. When all variables were considered together in a general linear model of determinants of MP, statistically significant (P < 0.05) relationships were found between MP density and serum L and Z, dietary L and Z intake, fiber intake, and iris color. CONCLUSIONS: These data suggest that MP values in this healthy adult population are lower than in smaller select samples. Moreover, these data indicate that MP is related to serum L and Z, dietary L and Z intake, fiber intake, and iris color.

21. Exp Eye Res. 2001 Apr;72(4):381-92.

Ligand-binding characterization of xanthophyll carotenoids to solubilized membrane proteins derived from human retina.

Yemelyanov AY, Katz NB, Bernstein PS.

Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT 84132, USA.

The macula of the human retina contains extraordinarily high concentrations of lutein and zeaxanthin, xanthophyll carotenoids that appear to play an important role in protecting against age-related macular degeneration, the leading cause of blindness among the elderly. It is likely that the uptake and stabilization of these carotenoids is mediated by specific xanthophyll-binding proteins. In order to purify and characterize such a binding protein, a carotenoid-rich membrane fraction derived from human macula or peripheral retina was prepared by homogenization, differential centrifugation, and detergent solubilization. Further purification was carried out using ion-exchange chromatography and gel-filtration chromatography coupled with continuous photodiode-array monitoring for endogenously associated xanthophyll carotenoids. The most highly purified preparations contained two major protein bands at 25 and 55 kDa that consistently co-eluted with endogenous lutein and zeaxanthin. The visible absorbance spectrum of the binding protein preparation closely matches the spectral absorbance of the human macular pigment, and it is bathochromically shifted about 10 nm from the spectrum of lutein and zeaxanthin dissolved in organic solvents. Binding of exogenously added lutein and zeaxanthin is saturable and specific with an apparent Kd of approximately 1 microM. Canthaxanthin and beta-carotene exhibit no significant binding activity to solubilized retinal membrane proteins when assayed under identical conditions. Other potential mammalian xanthophyll-binding proteins such as albumin, tubulin, lactoglobulin and serum lipoproteins possess only weak non-specific binding affinity for carotenoids when assayed under the same stringent binding conditions. This investigation provides the first direct evidence for the existence of specific xanthophyll-binding protein(s) in the vertebrate retina and macula. The possible roles of xanthophyll-binding proteins in normal macular function and in the pathogenesis of age-related macular degeneration remain to be elucidated.

22. Am J Epidemiol. 2001 Mar 1;153(5):424-32.

Lutein and zeaxanthin in the diet and serum and their relation to age-related maculopathy in the third national health and nutrition examination survey.

Mares-Perlman JA, Fisher AI, Klein R, Palta M, Block G, Millen AE, Wright JD.

Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School, 610 North Walnut Street, 460 WARF, Madison, WI 53705-2397, USA. maresp@epi.ophth.wisc.edu

Relations of the carotenoids lutein and zeaxanthin in the diet and serum to photographic evidence of early and late age-related maculopathy (ARM) among persons over age 40 years (n = 8,222) were examined. Inverse relations of these carotenoids in the diet or serum to any form of ARM were not observed overall. There was a direct relation of dietary levels to one type of early ARM (soft drusen). However, relations differed by age and race. In the youngest age groups who were at risk for developing early (ages 40-59 years) or late (ages 60-79 years) ARM, higher levels of lutein and zeaxanthin in the diet were related to lower odds for pigmentary abnormalities, one sign of early ARM (odds ratio among persons in high vs. low quintiles = 0.1, 95 percent confidence interval: 0.1, 0.3) and of late ARM (odds ratio = 0.1, 95 percent confidence interval: 0.0, 0.9) after adjustment for age, gender, alcohol use, hypertension, smoking, and body mass index. Relations of these carotenoids to ARM may be influenced by age and race and require further evaluation in separate populations and in prospective studies.

23. Invest Ophthalmol Vis Sci. 2000 Apr;41(5):1200-9.

Lutein and zeaxanthin concentrations in rod outer segment membranes from perifoveal and peripheral human retina.

Rapp LM, Maple SS, Choi JH.

Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas 77030, USA. lrapp@bcm.tmc.edu

PURPOSE: In addition to acting as an optical filter, macular (carotenoid) pigment has been hypothesized to function as an antioxidant in the human retina by inhibiting the peroxidation of long-chain polyunsaturated fatty acids. However, at its location of highest density in the inner (prereceptoral) layers of the foveal retina, a specific requirement for antioxidant protection would not be predicted. The purpose of this study was to determine whether lutein and zeaxanthin, the major carotenoids comprising the macular pigment, are present in rod outer segment (ROS) membranes where the concentration of long-chain polyunsaturated fatty acids, and susceptibility to oxidation, is highest. METHODS: Retinas from human donor eyes were dissected to obtain two regions: an annular ring of 1.5- to 4-mm eccentricity representing the area centralis excluding the fovea (perifoveal retina) and the remaining retina outside this region (peripheral retina). ROS and residual (ROS-depleted) retinal membranes were isolated from these regions by differential centrifugation and their purity checked by polyacrylamide gel electrophoresis and fatty acid analysis. Lutein and zeaxanthin were analyzed by high-performance liquid chromatography and their concentrations expressed relative to membrane protein. Preparation of membranes and analysis of carotenoids were performed in parallel on bovine retinas for comparison to a nonprimate species. Carotenoid concentrations were also determined for retinal pigment epithelium harvested from human eyes. RESULTS: ROS membranes prepared from perifoveal and peripheral regions of human retina were found to be of high purity as indicated by the presence of a dense opsin band on protein gels. Fatty acid analysis of human ROS membranes showed a characteristic enrichment of docosahexaenoic acid relative to residual membranes. Membranes prepared from bovine retinas had protein profiles and fatty acid composition similar to those from human retinas. Carotenoid analysis showed that lutein and zeaxanthin were present in ROS and residual human retinal membranes. The combined concentration of lutein plus zeaxanthin was 70% higher in human ROS than in residual membranes. Lutein plus zeaxanthin in human ROS membranes was 2.7 times more concentrated in the perifoveal than the peripheral retinal region. Lutein and zeaxanthin were consistently detected in human retinal pigment epithelium at relatively low concentrations. CONCLUSIONS: The presence of lutein and zeaxanthin in human ROS membranes raises the possibility that they function as antioxidants in this cell compartment. The finding of a higher concentration of these carotenoids in ROS of the perifoveal retina lends support to their proposed protective role in age-related macular degeneration.

24. Invest Ophthalmol Vis Sci. 2001 Jan;42(1):235-40.

Erratum in: Invest Ophthalmol Vis Sci 2001 Mar;42(3):548.

Macular pigment in donor eyes with and without AMD: a case-control study.

Bone RA, Landrum JT, Mayne ST, Gomez CM, Tibor SE, Twaroska EE.

Department of Physics, Florida International University, Miami, Florida 33199, USA. bone@fiu.edu

PURPOSE: To determine whether there is an association between the density of macular pigment in the human retina and the risk of age-related macular degeneration (AMD). METHODS: Retinas from 56 donors with AMD and 56 controls were cut into three concentric regions centered on the fovea. The inner, medial, and outer regions covered the visual angles 0 degrees to 5 degrees, 5 degrees to 19 degrees, and 19 degrees to 38 degrees, respectively. The amounts of lutein (L) and zeaxanthin (Z) extracted from each tissue sample were determined by high-performance liquid chromatography. RESULTS: L and Z levels in all three concentric regions were less, on average, for the AMD donors than for the controls. The differences decreased in magnitude from the inner to medial to outer regions. The lower levels found in the inner and medial regions for AMD donors may be attributable, in part, to the disease. Comparisons between AMD donors and controls using the outer (peripheral) region were considered more reliable. For this region, logistic regression analysis indicated that those in the highest quartile of L and Z level had an 82% lower risk for AMD compared with those in the lowest quartile (age- and sex-adjusted odds ratio = 0.18, 95% confidence interval = 0.05-0.64). CONCLUSIONS: The results are consistent with a theoretical model that proposes an inverse association between risk of AMD and the amounts of L and Z in the retina. The results are inconsistent with a model that attributes a loss of L and Z in the retina to the destructive effects of AMD.

25. Exp Eye Res. 2000 Sep;71(3):239-45.

Lutein and zeaxanthin in the eyes, serum and diet of human subjects.

Bone RA, Landrum JT, Dixon Z, Chen Y, Llerena CM.

Department of Physics, Florida International University, Miami, FL 33199, USA.

Inverse associations have been reported between the incidence of advanced, neovascular, age-related macular degeneration (AMD) and the combined lutein (L) and zeaxanthin (Z) intake in the diet, and L and Z concentration in the blood serum. We suggest that persons with high levels of L and Z in either the diet or serum would probably have, in addition, relatively high densities of these carotenoids in the macula, the so-called 'macular pigment'. Several lines of evidence point to a potential protective effect by the macular pigment against AMD. In this study we examined the relationship between dietary intake of L and Z using a food frequency questionnaire; concentration of L and Z in the serum, determined by high-performance liquid chromatography, and macular pigment optical density, obtained by flicker photometry. Nineteen subjects participated. We also analysed the serum and retinas, as autopsy samples, from 23 tissue donors in order to obtain the concentration of L and Z in these tissues. The results reveal positive, though weak, associations between dietary intake of L and Z and serum concentration of L and Z, and between serum concentration of L and Z and macular pigment density. We estimate that approximately half of the variability in the subjects' serum concentration of L and Z can be explained by their dietary intake of L and Z, and about one third of the variability in their macular pigment density can be attributed to their serum concentration of L and Z. These results, together with the reported associations between risk of AMD and dietary and serum L and Z, support the hypothesis that low concentrations of macular pigment may be associated with an increased risk of AMD. Copyright 2000 Academic Press.

26. Invest Ophthalmol Vis Sci. 2000 Oct;41(11):3322-6.

Influence of lutein supplementation on macular pigment, assessed with two objective techniques.

Berendschot TT, Goldbohm RA, Klopping WA, van de Kraats J, van Norel J, van Norren D.

University Medical Centre Utrecht, Department of Ophthalmology, The Netherlands. tosb@isi.uu.nl

PURPOSE: Macular pigment (MP) may protect against age-related macular degeneration. This study was conducted to determine the extent of changes in the macular pigment density as a consequence of oral supplementation with lutein. A second purpose was to compare two objective measurement techniques. METHODS: In the first technique, reflectance maps were made with a scanning laser ophthalmoscope. Digital subtraction of log reflectance maps and comparison between the foveal area and a 14 degrees temporal site provided MP density estimates. In the second technique, spectral fundus reflectance of the fovea was measured with a fundus reflectometer and analyzed with a detailed optical model, to arrive at MP density values. Eight subjects participated in this study. They took 10 mg lutein per day for 12 weeks. Plasma lutein concentration was measured at 4-week intervals. RESULTS: After 4 weeks, mean blood level of lutein had increased from 0.18 to 0.90 microM. It stayed at this level throughout the intake period and declined to 0.28 microM 4 weeks after termination. Measurement of the density of MP showed a within-subject variation of 10% with MP maps and 17% with spectral reflectance analysis. MP density showed a mean linear 4-week increase of 5.3% (P: < 0.001) and 4.1% (P: = 0. 022), respectively. CONCLUSIONS: Supplementation with lutein significantly increased the density of the MP. Analyzing reflectance maps with a scanning laser ophthalmoscope provided very reliable estimates of MP.

27. Optom Vis Sci. 1997 Jul;74(7):499-504.

Density of the human crystalline lens is related to the macular pigment carotenoids, lutein and zeaxanthin.

Hammond BR Jr, Wooten BR, Snodderly DM.

Vision Sciences Laboratory, College of Arts & Sciences, Arizona State University, Phoenix, USA. BHammond@asuvm.inre.asu.edu

PURPOSE: Although oxidative stress may play an important role in the development of age-related cataract, the degree of protection reported for antioxidant vitamins and carotenoids has been inconsistent across studies. These varied results may be due in part to the lack of good biomarkers for measuring the long-term nutritional status of the eye. The present experiments investigated the relationship between retinal carotenoids (i.e., macular pigment), used as a long-term measure of tissue carotenoids, and lens optical density, used as an indicator of lens health. METHODS: Macular pigment (460 nm) and lens (440, 500, and 550 nm) optical density were measured psychophysically in the same individuals. Groups of younger subjects--7 females (ages 24 to 36 years), and 5 males (ages 24 to 31 years)--were compared with older subjects--23 older females (ages 55 to 78 years), and 16 older males (ages 48 to 82 years). RESULTS: Lens density (440 nm) increased as a function of age (r = 0.65, p < 0.001), as expected. For the oldest group, a significant inverse relationship (y = 1.53-0.83x, r = -0.47, p < 0.001) was found between macular pigment density (440 nm) and lens density (440 nm). No relationship was found for the youngest group (p < 0.42). CONCLUSIONS: The main finding of this study was an age-dependent, inverse relationship between macular pigment density and lens density. Macular pigment is composed of lutein and zeaxanthin, the only two carotenoids that have been identified in the human lens. Thus, an inverse relationship between these two variables suggests that lutein and zeaxanthin, or other dietary factors with which they are correlated, may retard age-related increases in lens density.

28. Exp Eye Res. 1997 Jul;65(1):57-62.

A one year study of the macular pigment: the effect of 140 days of a lutein supplement.

Landrum JT, Bone RA, Joa H, Kilburn MD, Moore LL, Sprague KE.

Department of Chemistry, Florida International University, Miami, FL 33199, USA.

A low density of macular pigment may represent a risk factor for age-related macular degeneration (AMD) by permitting greater blue light damage. This study was carried out to determine the effects on macular pigment optical density of dietary supplementation with lutein, one of the pigment constituents. Two subjects consumed lutein esters, equivalent to 30 mg of free lutein per day, for a period of 140 days. Macular pigment optical density was determined by heterochromatic flicker photometry before, during, and after the supplementation period. Serum lutein concentration was also obtained through the analysis of blood samples by high-performance liquid chromatography. Twenty to 40 days after the subjects commenced taking the lutein supplement, their macular pigment optical density began to increase uniformly at an average rate of 1.13+/-0.12 milliabsorbance units/day. During this same period, the serum concentration of lutein increased roughly tenfold, approaching a steady state plateau. The optical density curve eventually levelled off 40 to 50 days after the subjects discontinued the supplement. During the same 40 to 50 days, the serum concentration returned to baseline. Thereafter, little or no decrease in optical density was observed. The mean increases in the macular pigment optical density were 39% and 21% in the eyes of the two subjects respectively. In conclusion, the modest period of supplementation has been estimated to have produced in the subjects a 30 to 40% reduction in blue light reaching the photoreceptors, Bruch's membrane, and the retinal pigment epithelium, the vulnerable tissues affected by AMD.

29. Curr Eye Res. 1999 Dec;19(6):491-5.

Lutein and zeaxanthin are associated with photoreceptors in the human retina.

Sommerburg OG, Siems WG, Hurst JS, Lewis JW, Kliger DS, van Kuijk FJ.

University of Texas Medical Branch, Department of Ophthalmology & Visual Sciences TX, Galveston 77555-1067, USA.

PURPOSE. Previous studies showed that lutein and zeaxanthin, the major human retinal carotenoids, are concentrated in the macula. In this study, the carotenoids in human macular and peripheral retina and the retinal pigment epithelium (RPE) were analyzed. They were also determined in the rod outer segments (ROS) before and after removal of extrinsic membrane proteins. METHODS. Carotenoids were extracted from the macular and peripheral sections of human retina and RPE with hexane in dim light and analyzed by high performance liquid chromatography (HPLC). ROS samples equivalent to the amount in a single retina were also analyzed. RESULTS. Retinal carotenoid amounts were similar to previous reports, but only low levels were detected in the RPE. Regional ratios of lutein:zeaxanthin were similar in the retina and RPE. Approximately 25% of the total retinal carotenoids were found in the ROS, indicating that a substantial portion of peripheral retinal carotenoids are present in the ROS. However, after removal of the extrinsic membrane proteins and subsequent analysis, carotenoids were not detected. CONCLUSIONS: Most of the carotenoids in the human peripheral retina are present in the ROS. These ROS carotenoids are associated with soluble or salt-dependently bound proteins.

Cataracts

30. Nutrition. 2003 Jan;19(1):21-4.

Lutein, but not alpha-tocopherol, supplementation improves visual function in patients with age-related cataracts: a 2-y double-blind, placebo-controlled pilot study.

Olmedilla B, Granado F, Blanco I, Vaquero M.

Unidad de Vitaminas, Seccion de Nutricion, Clinica Puerta de Hierro, Madrid, Spain. bolmedilla@hpth.insalud.es

OBJECTIVE: We investigated the effect of long-term antioxidant supplementation (lutein and alpha-tocopherol) on serum levels and visual performance in patients with cataracts. METHODS: Seventeen patients clinically diagnosed with age-related cataracts were randomized in a double-blind study involving dietary supplementation with lutein (15 mg; n = 5), alpha-tocopherol (100 mg; n = 6), or placebo (n = 6), three times a week for up to 2 y. Serum carotenoid and tocopherol concentrations were determined with quality-controlled high-performance liquid chromatography, and visual performance (visual acuity and glare sensitivity) and biochemical and hematologic indexes were monitored every 3 mo throughout the study. Changes in these parameters were assessed by General Linear Model (GLM) repeated measures analysis. RESULTS: Serum concentrations of lutein and alpha-tocopherol increased with supplementation, although statistical significance was reached only in the lutein group. Visual performance (visual acuity and glare sensitivity) improved in the lutein group, whereas there was a trend toward the maintenance of and decrease in visual acuity with alpha-tocopherol and placebo supplementation, respectively. No significant side effects or changes in biochemical or hematologic profiles were observed in any of the subjects during the study. CONCLUSIONS: Visual function in patients with age-related cataracts who received the lutein supplements improved, suggesting that a higher intake of lutein, through lutein-rich fruit and vegetables or supplements, may have beneficial effects on the visual performance of people with age-related cataracts.

31. Am J Clin Nutr. 1999 Oct;70(4):517-24.

Comment in: Am J Clin Nutr. 1999 Oct;70(4):431-2.

A prospective study of carotenoid intake and risk of cataract extraction in US men.

Brown L, Rimm EB, Seddon JM, Giovannucci EL, Chasan-Taber L, Spiegelman D, Willett WC, Hankinson SE.

Departments of Epidemiology, Nutrition, and Biostatistics, Harvard School of Public Health, Boston, MA 02115, USA. lisa.brown@channing.harvard.edu

BACKGROUND: Dietary antioxidants, including carotenoids, are hypothesized to decrease the risk of age-related cataracts by preventing oxidation of proteins or lipids within the lens. However, prospective epidemiologic data concerning this phenomenon are limited. OBJECTIVE: Our objective was to examine prospectively the association between carotenoid and vitamin A intakes and cataract extraction in men. DESIGN: US male health professionals (n = 36644) who were 45-75 y of age in 1986 were included in this prospective cohort study. Others were subsequently included as they became 45 y of age. A detailed dietary questionnaire was used to assess intake of carotenoids and other nutrients. During 8 y of follow-up, 840 cases of senile cataract extraction were documented. RESULTS: We observed a modestly lower risk of cataract extraction in men with higher intakes of lutein and zeaxanthin but not of other carotenoids (alpha-carotene, beta-carotene, lycopene, and beta-cryptoxanthin) or vitamin A after other potential risk factors, including age and smoking, were controlled for. Men in the highest fifth of lutein and zeaxanthin intake had a 19% lower risk of cataract relative to men in the lowest fifth (relative risk: 0.81; 95% CI: 0.65, 1.01; P for trend = 0.03). Among specific foods high in carotenoids, broccoli and spinach were most consistently associated with a lower risk of cataract. CONCLUSIONS: Lutein and zeaxanthin may decrease the risk of cataracts severe enough to require extraction, although this relation appears modest in magnitude. The present findings add support for recommendations to consume vegetables and fruit high in carotenoids daily.

32. Am J Clin Nutr. 1999 Oct;70(4):509-16.

Comment in: Am J Clin Nutr. 1999 Oct;70(4):431-2.

A prospective study of carotenoid and vitamin A intakes and risk of cataract extraction in US women.

Chasan-Taber L, Willett WC, Seddon JM, Stampfer MJ, Rosner B, Colditz GA, Speizer FE, Hankinson SE.

Department of Biostatistics and Epidemiology, School of Public Health and Health Sciences, University of Massachusetts, Amherst 01003, USA. LCT@schoolph.umass.edu

BACKGROUND: Oxidation of lens proteins plays a central role in the formation of age-related cataracts, suggesting that dietary antioxidants may play a role in prevention. However, the relation between specific antioxidants and risk of cataract remains uncertain. OBJECTIVE: Our objective was to examine prospectively the association between carotenoid and vitamin A intakes and cataract extraction in women. METHODS: A prospective cohort of registered female nurses aged 45-71 y and free of diagnosed cancer was followed; in 1980, 50461 were included and others were added as they became 45 y of age for a total of 77466. Information on nutrient intake was assessed by repeated administration of a food-frequency questionnaire during 12 y of follow-up. RESULTS: During 761762 person-years of follow-up, 1471 cataracts were extracted. After age, smoking, and other potential cataract risk factors were controlled for, those with the highest intake of lutein and zeaxanthin had a 22% decreased risk of cataract extraction compared with those in the lowest quintile (relative risk: 0.78; 95% CI: 0.63, 0.95; P for trend = 0.04). Other carotenoids (alpha-carotene, beta-carotene, lycopene, and beta-cryptoxanthin), vitamin A, and retinol were not associated with cataract in multivariate analysis. Increasing frequency of intakes of spinach and kale, foods rich in lutein, was associated with a moderate decrease in risk of cataract. CONCLUSIONS: Lutein and zeaxanthin and foods rich in these carotenoids may decrease the risk of cataracts severe enough to require extraction.

Lipoprotein excange

33. Int J Vitam Nutr Res. 2002 Oct;72(5):300-8.

Carotenoids, mostly the xanthophylls, exchange between plasma lipoproteins.

Tyssandier V, Choubert G, Grolier P, Borel P.

Unite Maladies Metaboliques et Micronutriments, INRA, Clermont-Ferrand/Theix, 63122 Saint-Genes-Champanelle, France.

Carotenoids are exclusively transported by lipoproteins; in vitro studies suggest that they might protect these particles against oxidation. Little is known about the factors that govern the distribution of these micronutrients among lipoproteins. The objective of this study was to assess whether carotenoids are exchanged between lipoproteins and what factors, if any, were involved. In the first experiment, different groups of trout were fed for five days with either a carotenoid-free diet or with diets containing 80 mg pure carotenoid per kilogram of feed. Lipoproteins were separated by ultracentrifugation and carotenoid-rich, high-density lipoproteins (HDL) were incubated for two hours at 37 degrees C with carotenoid-free, very low-density lipoproteins (VLDL), and vice versa. After incubation, lipoproteins were re-separated and carotenoids were quantified to measure the transfer. The same experiments were done in the presence of cholesteryl ester transfer protein (CETP) and lecithin cholesterol acyltransferase (LCAT) inhibitors. In a second experiment, the exchange was measured between human VLDL and HDL. In trout, incubation of carotenoid-rich HDL with carotenoid-free VLDL resulted in the appearance of carotenoids in VLDL, and inversely. The higher the hydrophobicity of a carotenoid, the lower its proportion in HDL after incubation. CETP and LCAT inhibitors significantly increased the proportion of carotenoids in HDL after incubation. Results obtained with human lipoproteins showed that the xanthophyll lutein transferred between lipoproteins, but could not show any carotenes (alpha-carotene, beta-carotene, and lycopene) transfer. We conclude that carotenoids, chiefly the xanthophylls, exchange between lipoproteins. The transfer depends on plasma factor(s) sensitive to CETP and/or LCAT inhibitors.

Cancer

34. Free Radic Res. 2002 Jul;36(7):791-802.

Carotenoids induce apoptosis in the T-lymphoblast cell line Jurkat E6.1.

Muller K, Carpenter KL, Challis IR, Skepper JN, Arends MJ.

Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK.

Epidemiologically, a high-carotenoid intake via a fruit- and vegetable-rich diet is associated with a decreased risk of various forms of cancer. The mechanisms by which carotenoids exert this protective effect are controversial. In this study, we examined the potency of a range of carotenoids commonly found in human plasma to induce apoptosis in Jurkat E6.1 malignant T-lymphoblast cells. At a concentration of 20 microM, the order of potency to induce apoptosis after 24 h was: beta-carotene > lycopene > lutein > beta-cryptoxanthin = zeaxanthin. Canthaxanthin failed to induce apoptosis under these conditions. beta-Carotene induced apoptosis in a time- and concentration-dependent manner with a lowest effective concentration of about 3 microM. Pre-conditioning of beta-carotene for 72 h destroyed its pro-apoptotic activity almost completely, whereas degradation for 6 h or less did not, indicating that either beta-carotene itself and/or an early degradation product of beta-carotene are the death-inducing compounds. Apoptosis induced by beta-carotene was characterized by chromatin condensation and nuclear fragmentation, DNA degradation, PARP cleavage and caspase-3 activation. The antioxidant BO-653 inhibited the degradation of beta-carotene in vitro and significantly increased its cytotoxicity, indicating that a pro-oxidant effect of beta-carotene is unlikely to cause its pro-apoptotic activity. The induction of apoptosis in transformed cells by carotenoids may explain their protective effect against cancer formation in humans. Possible pathways for induction of apoptosis by carotenoids are discussed.

35. Clin Nutr. 2002 Apr;21(2):161-4.

The relationship between reduced vitamin antioxidant concentrations and the systemic inflammatory response in patients with common solid tumours.

McMillan DC, Talwar D, Sattar N, Underwood M, O'Reilly DS, McArdle C.

University Department of Surgery, Glasgow, UK.

BACKGROUND AND AIMS: The majority of patients with advanced cancer have reduced circulating concentrations of the vitamin antioxidants including retinol, alpha-tocopherol and carotenoids. However, the basis of this reduction is not known. Vitamin antioxidant concentrations have been reported to be correlated with a systemic inflammatory response (as evidenced by C-reactive protein) in normal subjects and in patients with lung cancer. In order to determine whether this relationship was independent of tumour type patients other common solid tumours were studied. METHODS: Fasting circulating concentrations of vitamin antioxidants and C-reactive protein were measured in normal subjects (n=30) and patients with breast (n=15), prostate (n=15) and colorectal cancer (n=11). RESULTS: Concentrations of C-reactive protein were higher (P<0.0001) and vitamin antioxidants lower (P<0.0001) in the cancer patients. In normal subjects and cancer patients, C-reactive protein concentrations were inversely correlated with circulating concentrations of retinol (r(2)=0.162), alpha-tocopherol (r(2)=0.297), lutein (r(2)=0.256), lycopene (r(2)=-0.171), alpha-(r(2)=0.140) and beta-carotene (r(2)=0.254): (all P<0.001). CONCLUSIONS: Concentrations of retinol, alpha -tocopherol and carotenoids are inversely associated with the magnitude of the systemic inflammatory response. These relationships appear to be independent of the presence and type of cancer. Copyright 2002 Elsevier Science Ltd.

36. Cancer Epidemiol Biomarkers Prev. 2000 Mar;9(3):257-63.

Differential regulation of apoptosis in normal versus transformed mammary epithelium by lutein and retinoic acid.

Sumantran VN, Zhang R, Lee DS, Wicha MS.

Department of Internal Medicine and Comprehensive Cancer Center, University of Michigan, Ann Arbor 48109-0942, USA.

We examined the effects of all-trans retinoic acid (ATRA) and lutein (a nonprovitamin A carotenoid), on apoptosis and chemosensitivity in primary normal human mammary epithelial cells, SV40 transformed mammary cells, and MCF-7 human mammary carcinoma cells. ATRA and lutein selectively induced apoptosis in transformed but not normal human mammary cells. In addition, both compounds protected normal cells, but not transformed cells, from apoptosis induced by the chemotherapy agents etoposide and cisplatin. Furthermore, lutein and ATRA selectively increased the ratio of Bcl-xL:Bax protein expression in normal cells but not transformed mammary cells, suggesting a possible mechanism for selective modulation of apoptosis. The differential effects of lutein and ATRA on apoptotic pathways in normal versus transformed mammary epithelial cells may have important implications for chemoprevention and therapy.

Safety

37. Food Chem Toxicol. 2002 Nov;40(11):1535-49.

An innovative approach to the determination of safety for a dietary ingredient derived from a new source: case study using a crystalline lutein product.

Kruger CL, Murphy M, DeFreitas Z, Pfannkuch F, Heimbach J.

ENVIRON International Corporation, 4350 Fairfax Drive, Arlington, VA 22203, USA. ckruger@environcorp.com

Lutein and zeaxanthin are antioxidant carotenoids that occur naturally in the diet. A new source of these carotenoids, a crystalline lutein product, is an extract from the marigold flower (Tagetes erecta) that contains approximately 86% by weight of the carotenoids lutein and zeaxanthin. The safety of consumption of a crystalline lutein product used as an ingredient in food is determined by evaluating the safety of ingestion of the whole product, as well as safety of ingestion of the major constituents, lutein and zeaxanthin. The approach to evaluating the safety of increased lutein and zeaxanthin intake from consumption of crystalline lutein product is based on an evaluation of the incremental increase this ingestion will produce in lutein and zeaxanthin and in total carotenoids, compared to background exposure. In addition, bioavailability of lutein+zeaxanthin from crystalline lutein product, when added to food, is determined and used to adjust the estimated daily intake of lutein and zeaxanthin from this new source and standardize it to the bioavailable dose of these carotenoids from food sources. The proposed level of ingestion of lutein and zeaxanthin from the crystalline lutein product would increase intake of lutein zeaxanthin in the generally vegetable-poor American diet to a level comparable to the mean intake of individuals consuming the recommended number of servings of vegetables per day and is therefore determined to be both prudent and safe. Safety of consumption of the whole product is determined by evaluating the source of the product, production process, nature and quantity of impurities, and product specifications. Corroboration of safety is provided by animal toxicology studies of the crystalline lutein product, as well as human and epidemiologic studies of lutein and zeaxanthin intake. It can be concluded that crystalline lutein is a safe and GRAS source of lutein for its proposed uses in food.

UVB irradiation

38. Photochem Photobiol. 2002 May;75(5):503-6.

Divergent optimum levels of lycopene, beta-carotene and lutein protecting against UVB irradiation in human fibroblastst.

Eichler O, Sies H, Stahl W.

Institut fur Physiologische Chemie I and Biologisch-Medizinisches Forschunggzentrum, Heinrich-Heine-Universitat Dusseldorf, Germany.

Exposure of living organisms to UV light leads to photooxidative reactions. Peroxyl radicals are involved in the propagation of lipid peroxidation. Carotenoids are dietary antioxidants and show photoprotective effects in human skin, efficiently scavenging peroxyl radicals and inhibiting lipid peroxidation. Cultured human skin fibroblasts were used to examine the protective effects of the carotenoids, lycopene, beta-carotene and lutein on UVB-induced lipid peroxidation. The carotenoids were delivered to the cells using liposomes as the vehicle. The cells were exposed to UVB light for 20 min. Lycopene, beta-carotene and lutein were capable of decreasing UV-induced formation of thiobarbituric acid-reactive substances at 1 h to levels 40-50% of controls free of carotenoids. The amounts of carotenoid needed for optimal protection were divergent at 0.05, 0.40 and 0.30 nmol/mg protein for lycopene, beta-carotene and lutein, respectively. Beyond the optimum levels, further increases of carotenoid levels in cells led to prooxidant effects.

Serum responses

39. Clin Sci (Lond). 2002 Apr;102(4):447-56.

A European multicentre, placebo-controlled supplementation study with alpha-tocopherol, carotene-rich palm oil, lutein or lycopene: analysis of serum responses.

Olmedilla B, Granado F, Southon S, Wright AJ, Blanco I, Gil-Martinez E, van den Berg H, Thurnham D, Corridan B, Chopra M, Hininger I.

Unidad de Vitaminas, Seccion de Nutricion, Clinica Puerta de Hierro, C/San Martin de Porres 4, 28035-Madrid, Spain. bolmedilla@hpth.insalud.es

Increased levels of oxidative stress have been implicated in tissue damage and the development of chronic diseases, and dietary antioxidants may reduce the risk of oxidative tissue damage. As part of a European multicentre project, several studies were undertaken with the aim of testing whether the consumption of foods rich in carotenoids reduces oxidative damage to human tissue components. We describe here the serum response of carotenoids and tocopherols upon supplementation with carotenoids from natural extracts (alpha-carotene+beta-carotene, lutein or lycopene; 15 mg/day) and/or with alpha-tocopherol (100 mg/day) in a multicentre, placebo-controlled intervention study in 400 healthy male and female volunteers, aged 25-45 years, from five European regions (France, Northern Ireland, Republic of Ireland, The Netherlands and Spain). Supplementation with alpha-tocopherol increased serum alpha-tocopherol levels, while producing a marked decrease in serum gamma-tocopherol. Supplementation with alpha- + beta-carotene (carotene-rich palm oil) resulted in 14-fold and 5-fold increases respectively in serum levels of these carotenoids. Supplementation with lutein (from marigold extracts) elevated serum lutein (approx. 5-fold), zeaxanthin (approx. doubled) and ketocarotenoids (although these were not present in the supplement), whereas lycopene supplementation (from tomato paste) resulted in a 2-fold increase in serum lycopene. The isomer distributions of beta-carotene and lycopene in serum remained constant regardless of the isomer composition in the capsules. In Spanish volunteers, additional data showed that the serum response to carotenoid supplementation reached a plateau after 4 weeks, and no significant side effects (except carotenodermia) or changes in biochemical or haematological indices were observed throughout the study. This part of the study describes dose-time responses, isomer distribution, subject variability and side effects during supplementation with the major dietary carotenoids in healthy subjects.

40. Am J Clin Nutr. 2000 May;71(5):1187-93.

Comment in: Am J Clin Nutr. 2000 May;71(5):1029-30.

Amount of fat in the diet affects bioavailability of lutein esters but not of alpha-carotene, beta-carotene, and vitamin E in humans.

Roodenburg AJ, Leenen R, van het Hof KH, Weststrate JA, Tijburg LB.

Unilever Health Institute, Unilever Research Vlaardingen, Vlaardingen, Netherlands. annet.roodenburg@unilever.com

BACKGROUND: Fat-soluble vitamin E and carotenoids are regarded as being protective against chronic diseases. Little is known about the effect of dietary fat on the bioavailability of these compounds. OBJECTIVE: The objective of this study was to assess the effect of the amount of dietary fat on plasma concentrations of vitamin E and carotenoids after supplementation with these compounds. DESIGN: During two 7-d periods, 4 groups of 14-15 volunteers received daily, with a low-fat hot meal, 1 of 4 different supplements: vitamin E (50 mg), alpha- plus beta-carotene (8 mg), lutein esters (8 mg lutein), or placebo. The supplements were provided in a low- or high-fat spread supplied in random sequence during either of the 2 experimental periods. RESULTS: As anticipated, plasma concentrations of vitamin E, alpha- and beta-carotene, and lutein were significantly higher in the supplemented groups than in the placebo group. The amount of dietary fat consumed with the hot meal (3 or 36 g) did not affect the increases in plasma concentrations of vitamin E (20% increase with the low-fat spread and 23% increase with the high-fat spread) or alpha- and beta-carotene (315% and 139% with the low-fat spread and 226% and 108% with the high-fat spread). The plasma lutein response was higher when lutein esters were consumed with the high-fat spread (207% increase) than with the low-fat spread (88% increase). CONCLUSION: Optimal uptake of vitamin E and alpha- and beta-carotene requires a limited amount of fat whereas the amount of fat required for optimal intestinal uptake of lutein esters is higher. 2000;71:-93.

Lung function/cancer

41. Am J Epidemiol. 2002 Mar 1;155(5):463-71.

Lung function in relation to intake of carotenoids and other antioxidant vitamins in a population-based study.

Schunemann HJ, McCann S, Grant BJ, Trevisan M, Muti P, Freudenheim JL.

Department of Medicine, School of Medicine and Biomedical Sciences, State University of New York, 207 Farber Hall, 3435 Main Street, Buffalo, NY 14214-3000, USA. HJS@buffalo.edu

Accumulating evidence suggests that dietary antioxidant vitamins are positively associated with lung function. No evidence exists regarding whether dietary carotenoids other than beta-carotene are related to pulmonary function. In 1995--1998 the authors studied the association of forced expiratory volume in 1 second and forced vital capacity as the percentage of the predicted value (FEV(1)% and FVC%, respectively) after adjustment for height, age, gender, and race with the intakes of several carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin, and lycopene) in a random sample of 1,616 men and women who were residents of western New York State, aged 35--79 years, and free from respiratory disease. They observed significant associations of lutein/zeaxanthin and vitamins C and E with FEV(1)% and FVC% using multiple linear regression after adjustment for total energy intake, smoking, and other covariates. When they analyzed all of these antioxidant vitamins simultaneously, they observed the strongest association of vitamin E with FEV(1)% and of lutein/zeaxanthin with FVC%. The differences in forced expiratory volume in 1 second and forced vital capacity associated with a decrease of 1 standard deviation of dietary vitamin E or lutein/zeaxanthin were equivalent to the influence of approximately 1--2 years of aging. Their findings support the hypothesis that carotenoids, vitamin C, and vitamin E may play a role in respiratory health and that carotenoids other than beta-carotene may be involved.

42. Cancer Epidemiol Biomarkers Prev. 2000 Apr;9(4):357-65.

A prospective cohort study on antioxidant and folate intake and male lung cancer risk.

Voorrips LE, Goldbohm RA, Brants HA, van Poppel GA, Sturmans F, Hermus RJ, van den Brandt PA.

Department of Nutritional Epidemiology, TNO Nutrition and Food Research Institute, Zeist, The Netherlands. Voorrips@voeding.tno.nl

Many studies have reported inverse associations between vegetable and fruit consumption and lung cancer risk. The aim of the present study was to elucidate the role of several antioxidants and folate in this relationship. In the Netherlands Cohort Study on Diet and Cancer, 58,279 men of ages 55-69 years at baseline in 1986 returned a questionnaire including a 150-item food frequency questionnaire. After 6.3 years of follow-up, 939 male lung cancer cases were registered. A new Dutch carotenoid database was used to estimate intake of alpha-carotene, beta-carotene, lutein + zeaxanthin, beta-cryptoxanthin, and lycopene, completed with the antioxidant vitamins C and E and folate. Using case-cohort analysis, rate ratios were calculated, adjusted for age, smoking, educational level, and family history of lung cancer. Protective effects on lung cancer incidence were found for lutein + zeaxanthin, beta-cryptoxanthin, folate, and vitamin C. Other carotenoids (alpha-carotene, beta-carotene, and lycopene) and vitamin E did not show significant associations. After adjustment for vitamin C, only folate remained inversely associated, and after adjustment for folate, only beta-cryptoxanthin and vitamin C remained significantly associated. Inverse associations were strongest among current smokers and weaker for former smokers at baseline. Inverse associations with carotenes, lutein + zeaxanthin, and beta-cryptoxanthin seemed to be limited to small cell and squamous cell carcinomas. Only folate and vitamin C intake appeared to be inversely related to small cell and squamous cell carcinomas and adenocarcinomas. Folate, vitamin C, and beta-cryptoxanthin might be better protective agents against lung cancer in smokers than alpha-carotene, beta-carotene, lutein + zeaxanthin, and lycopene.

Ovarian cancer

43. Ann Oncol. 2001 Nov;12(11):1589-93.

Micronutrients and ovarian cancer: a case-control study in Italy.

Bidoli E, La Vecchia C, Talamini R, Negri E, Parpinel M, Conti E, Montella M, Carbone MA, Franceschi S.

Servizio di Epidemiologia, Centro di Riferimento Oncologico, Aviano Italy. epidemiology@cro.it

BACKGROUND: The role of selected micronutrients, vitamins and minerals in the aetiology of epithelial ovarian cancer was investigated using data from a case-control study conducted between 1992 and 1999 in five Italian areas. PATIENTS AND METHODS: Cases were 1,031 patients with histologically confirmed incident epithelial ovarian cancer. Controls were 2,411 subjects admitted for acute, non-neoplastic diseases to major hospitals in the same catchment areas. Dietary habits were elicited using a validated food frequency questionnaire including 78 food groups and recipes. Odds ratios (OR) and 95% confidence intervals (95% CI) were computed by quintiles of intake of nutrients. RESULTS: Inverse associations emerged for vitamin E (OR = 0.6; 95% CI: 0.5-0.8), beta-carotene (OR = 0.8; 95% CI: 0.6-1.0), lutein/zeaxanthin (OR = 0.6; 95% CI: 0.5-0.8 for the highest vs. the lowest quintile of intake), and calcium intake (OR = 0.7; 95% CI: 0.6-1.0). When the combined effect of calcium and vitamin E was considered, the OR reached 0.4 (95% CI: 0.3-0.7) for subjects in the highest compared to those in the lowest intake tertile of both micronutrients. Results were consistent across strata of menopausal status, parity and family history of ovarian or breast cancer. CONCLUSIONS: The intake of selected micronutrients, which were positively correlated to a diet rich in vegetables and fruits, was inversely associated with ovarian cancer.

Osteoarthritis

44. Public Health Nutr. 2001 Oct;4(5):935-42.

Serum carotenoids and radiographic knee osteoarthritis: the Johnston County Osteoarthritis Project.

De Roos AJ, Arab L, Renner JB, Craft N, Luta G, Helmick CG, Hochberg MC, Jordan JM.

National Cancer Institute, Bethesda, MD, USA.

OBJECTIVE: Antioxidant intake has been associated with less progression of radiographic knee osteoarthritis (OA), but studies of carotenoid biomarkers and OA have not been done. We examined associations between serum concentrations of nine naturally occurring carotenoids and radiographic knee OA. DESIGN: The study design was matched case-control. Sera were analysed by high-performance liquid chromatography for nine carotenoids: lutein, zeaxanthin, alpha- and beta-cryptoxanthin, trans- and cis-lycopene, alpha-carotene, and trans- and cis-beta-carotene. Conditional logistic regression was used to estimate the association between tertiles of each carotenoid and radiographic knee OA, independent of body mass index, education, serum cholesterol, and the other carotenoids. SETTING: Johnston County, North Carolina, United States of America. SUBJECTS: Two-hundred cases with radiographic knee OA (Kellgren-Lawrence grades > or = 2) and 200 controls (Kellgren-Lawrence grade = 0) were randomly selected from the Johnston County Osteoarthritis Project, and were matched on age, gender and race. RESULTS: Participants with serum levels of lutein or beta-cryptoxanthin in the highest tertile were approximately 70% less likely to have knee OA than controls (odds ratio (OR) [95% confidence interval (CI)] = 0.28 [0.11, 0.73] and 0.36 [0.14, 0.95], respectively). Those in the highest tertile of trans-beta-carotene (OR = 6.40 [1.86, 22.1]) and zeaxanthin (OR = 3.06 [1.19, 7.85]) were more likely to have knee OA. CONCLUSIONS: While certain carotenoids may protect against knee OA, others may increase the odds of knee OA. Further study of carotenoids and knee OA are warranted before clinical recommendations about these substances and knee OA can be made.

Cervical intraepithelial neoplasia

45 .Cancer Epidemiol Biomarkers Prev. 2001 Nov;10(11):1219-22.

Serum carotenoids and risk of cervical intraepithelial neoplasia in Southwestern American Indian women.

Schiff MA, Patterson RE, Baumgartner RN, Masuk M, van Asselt-King L, Wheeler CM, Becker TM.

University of Washington, Department of Epidemiology, Seattle, Washington 98115, USA.

The objective of this research was to evaluate the association between serum carotenoids and cervical intraepithelial neoplasia (CIN) among Southwestern American Indian women. Cases were American Indian women with biopsy-proven CIN II/III cervical lesions (n = 81) diagnosed between November 1994 and October 1997. Controls were American Indian women from the same clinics with normal cervical epithelium (n = 160). All of the subjects underwent interviews and laboratory evaluations. Interviews evaluated demographic information, sexual history, and cigarette smoking. Serum concentrations of alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, and lutein/zeaxanthin were measured by high performance liquid chromatography. Cervical human papillomavirus infection was detected using a PCR-based test. Increasing levels of alpha-carotene, beta-cryptoxanthin, and lutein/zeaxanthin were associated with decreasing risk of CIN II/III. In addition, the highest tertiles of beta-cryptoxanthin (odds ratio = 0.39, 95% confidence interval = 0.17-0.91) and lutein/zeaxanthin (odds ratio = 0.40, 95% confidence interval = 0.17-0.95) were associated with the lowest risk of CIN. In conclusion, specially targeted intervention efforts to increase consumption of fruits and vegetables may protect Southwestern American Indian women from developing CIN.

Endometrial cancer

46. Cancer Causes Control. 2000 Dec;11(10):965-74.

Diet in the epidemiology of endometrial cancer in western New York (United States).

McCann SE, Freudenheim JL, Marshall JR, Brasure JR, Swanson MK, Graham S.

Department of Social and Preventive Medicine, State University of New York at Buffalo, 14214, USA.

OBJECTIVES: We examined diet and risk of endometrial cancer among women in the Western New York Diet Study (1986-1991). METHODS: Self-reported frequency of use of 172 foods and beverages during the 2 years before the interview and other relevant data were collected by detailed interviews from 232 endometrial cancer cases and 639 controls, frequency-matched for age and county of residence. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by unconditional logistic regression, adjusting for age, education, body mass index (BMI), smoking history, hypertension, diabetes, age at menarche, parity, oral contraceptive use, menopausal status, menopausal estrogen use, and energy. RESULTS: Risks were reduced for women in the highest quartiles of intake of protein (OR 0.4, 95% CI: 0.2-0.9), dietary fiber (OR 0.5, 95% CI: 0.3-1.0), phytosterols (OR 0.6, 95% CI: 0.3-1.0), vitamin C (OR 0.5, 95% CI: 0.3-0.8) folate (OR 0.4, 95% CI: 0.2-0.7), alpha-carotene (OR 0.6, 95% CI: 0.4-1.0), beta-carotene (OR 0.4, 95% CI: 0.2-0.6), lycopene (OR 0.6, 95% CI: 0.4-1.0), lutein + zeaxanthin (OR 0.3, 95% CI: 0.2-0.5) and vegetables (OR 0.5, 95% CI: 0.3-0.9), but unrelated to energy (OR 0.9, 95% CI: 0.6-1.5) or fat (OR 1.6, 95% CI: 0.7-3.4). CONCLUSIONS: Our results support previous findings of reduced endometrial cancer risks associated with a diet high in plant foods.

Gastric ulcer

47. J Clin Gastroenterol. 2000 Jun;30(4):381-5.

Comment in: J Clin Gastroenterol. 2000 Jun;30(4):341-2. J Clin Gastroenterol. 2001 Jan;32(1):91-2.

Micronutrient antioxidants in gastric mucosa and serum in patients with gastritis and gastric ulcer: does Helicobacter pylori infection affect the mucosal levels?

Nair S, Norkus EP, Hertan H, Pitchumoni CS.

Division of Gastroenterology, Johns Hopkins University School of Medicine Baltimore, Maryland, USA.

Free radicals (FRs) play an important role in the pathogenesis of gastroduodenal mucosal inflammation, peptic ulcer disease, and probably even gastric cancer. Various micronutrients protect the gastric mucosa by scavenging FRs. Only limited data is available regarding the concentration of micronutrients in the gastric mucosa in patients with gastritis and peptic ulcer disease. Our aim was to analyze micronutrient antioxidant concentrations in the antral mucosa in patients with gastritis and gastric ulcer and to determine the influence of Helicobacter pylori infection on gastric mucosal antioxidants in patients with gastritis and gastric ulcer. Patients who underwent upper endoscopy for evaluation of dyspepsia were included in the study. Ascorbic acid, alpha-tocopherol, alpha-carotene, beta-carotene, total carotenoids, lutein, cryptoxanthin, and lycopene levels were measured in the sera and antral mucosal biopsies in these patients. The diagnosis of H. pylori was confirmed by histology, urease test (CLO) and serology. Patients with negative endoscopic findings and normal histology and no H. pylori infection served as controls. In patients with gastritis, alpha-tocopherol levels were reduced in serum and mucosa irrespective of H. pylori status, whereas carotenoids and ascorbic acid levels were similar to controls. However, in patients with gastric ulcer, serum and mucosal levels of all micronutrient antioxidants were markedly decreased compared with both controls and patients with gastritis. The degree of depletion of antioxidants was similar in patients with either H. pylori-induced or nonsteroidal antiinflammatory drug (NSAID)-induced ulcers. Patients with gastric ulcer have very low gastric antioxidant concentrations compared to patients with gastritis and normal mucosa. This depletion in antioxidants seems to be a nonspecific response and was not related to H. pylori infection.

Homocysteine

48. J Nutr. 2000 Jun;130(6):1578-83.

Fruits and vegetables increase plasma carotenoids and vitamins and decrease homocysteine in humans.

Broekmans WM, Klopping-Ketelaars IA, Schuurman CR, Verhagen H, van den Berg H, Kok FJ, van Poppel G.

TNO Nutrition and Food Research, 3700 AJ Zeist, The Netherlands.

Observational epidemiologic studies have shown that a high consumption of fruits and vegetables is associated with a decreased risk of chronic diseases. Little is known about the bioavailability of constituents from vegetables and fruits and the effect of these constituents on markers for disease risk. Currently, the recommendation is to increase intake of a mix of fruits and vegetables ("five a day"). We investigated the effect of this recommendation on plasma carotenoids, vitamins and homocysteine concentrations in a 4-wk dietary controlled, parallel intervention study. Male and female volunteers (n = 47) were allocated randomly to either a daily 500-g fruit and vegetable ("high") diet or a 100-g fruit and vegetable ("low") diet. Analyzed total carotenoid, vitamin C and folate concentrations of the daily high diet were 13.3 mg, 173 mg and 228.1 microg, respectively. The daily low diet contained 2.9 mg carotenoids, 65 mg vitamin C and 131.1 microg folate. Differences in final plasma levels between the high and low group were as follows: lutein, 46% [95% confidence interval (CI) 28-64]; beta-cryptoxanthin, 128% (98-159); lycopene, 22% (8-37); alpha-carotene, 121% (94-149); beta-carotene, 45% (28-62); and vitamin C, 64% (51-77) (P < 0.05). The high group had an 11% (-18 to -4) lower final plasma homocysteine and a 15% (0.8-30) higher plasma folate concentration compared with the low group (P < 0.05). This is the first trial to show that a mix of fruits and vegetables, with a moderate folate content, decreases plasma homocysteine concentrations in humans.

Crohn's

49. J Physiol Paris. 2000 Mar-Apr;94(2):159-61.

Decrease of serum carotenoids in Crohn's disease.

Rumi G Jr, Szabo I, Vincze A, Matus Z, Toth G, Mozsik G.

First Department of Medicine, University Medical School of Pecs, Hungary.

Crohn's disease (CD) is frequently complicated by various nutritional disturbances. Although it is important to correct these disturbances, the nutritional status of CD patients has been poorly documented, especially concerning vitamin status. The aims of this study were (a) to measure the serum concentrations of vitamin A and six other carotenoids (lutein, zeaxanthin, alpha-, beta-carotene, alpha-, beta-cryptoxanthin) in patients with CD and to compare them with those in healthy controls and (b) to follow the changes of serum carotenoid levels in CD patients during treatment. Twenty-eight patients with CD and 23 healthy persons were included in this study. The results of twelve patients were followed up through one year. The patients were free of any nutritional treatment. The serum concentrations of carotenoids were measured with high-pressure liquid chromatography (HPLC). The serum concentrations of five carotenoids were significantly lower in the patients than in the controls (vitamin A, zeaxanthin: P < 0.001; alpha-, beta-carotene: P < 0.01; lutein: P < 0.05). The carotenoid status of the followed patients advanced to the normal range, but this increase was not significant. These findings suggest that there is a deficiency of vitamin A and its provitamins in Crohn' s disease prior to treatment. However, because we did not evaluate the vitamin intake in this study, we could not conclude which of the factors--poor intake, increased requirement, or malabsorption--was more important in decreasing of carotenoid levels.

Prostate cancer

50. J Natl Cancer Inst. 2000 Jan 5;92(1):61-8.

Fruit and vegetable intakes and prostate cancer risk.

Cohen JH, Kristal AR, Stanford JL.

Cancer Prevention Research Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA. jcohen@fhcrc.org

BACKGROUND: There is extensive and consistent evidence that high fruit and vegetable intakes are associated with decreased risks of many cancers, but results for prostate cancer risk have been inconsistent. We studied the associations of fruit and vegetable intakes with prostate cancer risk in a population-based, case-control study of men under 65 years of age. METHODS: Case participants were 628 men from King County (Seattle area), WA, who were newly diagnosed with prostate cancer. Control participants were 602 men recruited from the same underlying population and frequency matched to case participants by age. Self-administered food-frequency questionnaires were used to assess diet over the 3- to 5-year period before diagnosis or recruitment. Daily nutrient intakes were calculated by use of a nutrient database with recently updated analytic values for carotenoids. Odds ratios for prostate cancer risk associated with foods and nutrients were calculated by use of unconditional logistic regression. RESULTS: No associations were found between fruit intake and prostate cancer risk. The adjusted odds ratio (ORs) for the comparison of 28 or more servings of vegetables per week with fewer than 14 servings per week was 0.65 (95% confidence interval [CI] = 0.45-0.94), with a two-sided P for trend =.01. For cruciferous vegetable consumption, adjusted for covariates and total vegetable intake, the OR for comparison of three or more servings per week with less than one serving per week was 0.59 (95% CI = 0.39-0.90), with a two-sided P for trend =.02. The OR for daily intake of 2000 microg or more lutein plus zeaxanthin compared with an intake of less than 800 microg was 0.68 (95% CI = 0.45-1.00). CONCLUSION: These results suggest that high consumption of vegetables, particularly cruciferous vegetables, is associated with a reduced risk of prostate cancer.