The relationship between serum concentrations of beta-cryptoxanthin and
zeaxanthin and the consumption of cigarettes and alcohol or the intake
frequencies of foods was investigated in 775 Japanese inhabitants. Serum
concentrations of beta-cryptoxanthin and beta-carotene in healthy Japanese aged 40-70 years were higher in females than in males. Serum beta-cryptoxanthin levels were inversely associated with the consumption of cigarettes and alcohol, as were the serum beta-carotene levels. Serum zeaxanthin (including lutein) levels were associated with cigarette consumption. The levels of serum beta-cryptoxanthin were positively correlated with the intake frequency of some fruits, and those of zeaxanthin, with the intake frequency of green vegetables, milk and eggs. These xanthophylls may play a role with beta-carotene in smoking-related cancer prevention.

This is a further analysis of a case-control study of 452 prostate cancer cases
and 899 population controls that was conducted in 1970-1983 among the
multiethnic population of Hawaii. Because a previous analysis had shown a
positive association with intake of beta-carotene, a nutrient presently being
tested for chemoprevention, the authors reexamined the data for consistency
among the main food sources of beta-carotene. Vegetables and fruits containing
other phytochemicals suspected to be cancer inhibitors were also examined. With the exception of papaya, which was positively associated with risk among men aged 70 years and older, consumption of other yellow-orange fruits and
vegetables, tomatoes, dark green vegetables, and cruciferous vegetables was not associated with prostate cancer risk. These results suggest that: 1) the
positive association with beta-carotene intake among older men that the authors
previously reported was essentially due to the greater papaya consumption of
cases compared with controls; and 2) intake of beta-carotene, lycopene, lutein,
indoles, phenols, or other phytochemicals is not associated with prostate cancer
risk.

This is a further analysis of a case-control study of 452 prostate cancer cases
and 899 population controls that was conducted in 1970-1983 among the
multiethnic population of Hawaii. Because a previous analysis had shown a
positive association with intake of beta-carotene, a nutrient presently being
tested for chemoprevention, the authors reexamined the data for consistency
among the main food sources of beta-carotene. Vegetables and fruits containing
other phytochemicals suspected to be cancer inhibitors were also examined. With the exception of papaya, which was positively associated with risk among men aged 70 years and older, consumption of other yellow-orange fruits and
vegetables, tomatoes, dark green vegetables, and cruciferous vegetables was not associated with prostate cancer risk. These results suggest that: 1) the
positive association with beta-carotene intake among older men that the authors
previously reported was essentially due to the greater papaya consumption of
cases compared with controls; and 2) intake of beta-carotene, lycopene, lutein,
indoles, phenols, or other phytochemicals is not associated with prostate cancer
risk.

We examined the carotenoid content of selected foods consistently found to be
associated with a lower risk for various epithelial cancers in epidemiologic
studies. Both raw and cooked samples of green, leafy vegetables and yellow or
orange vegetables were quantitatively examined by high-performance liquid
chromatography for individual carotenoid content. The results indicated that
fresh, green, leafy vegetables were moderately high in beta carotene (0.5-14.6
mg/100 g) and very high in oxygenated carotenoids or xanthophylls, primarily
lutein and its stereoisomers (2.3-63.0 mg/100g) [corrected]. The fresh, yellow
or orange vegetables examined were very high in beta carotene (16.0-120.5 mg/100 g) [corrected] but had no detectable nonhydrocarbon carotenoids. Cooking differentially reduced the lutein content compared with the beta carotene content in green, leafy vegetables. These analyses suggest that consumption of carotenoids in addition to beta carotene may be associated with a lower risk for cancer.

The incidence of adenocarcinomas of the esophagus and gastric cardia (ACEGC) has been increasing for the past 10-15 years in the United States. The reason for this increase is unknown. This hospital-based case-control study was conducted to assess the effects of dietary and nutritional factors on the risk of ACECG. A total of 95 incident cases with pathological diagnosis and 132 cancer-free controls were included in the study. Patients were recruited at Memorial Sloan-Kettering Cancer Center from 1 November 1992 to 1 November 1994. Epidemiologic data were collected by a modified National Cancer Institute Health Habits History Questionnaire. Nutritional and dietary factors were analyzed using a logistic regression model. Increased risk of ACEGC was significantly related to higher intake of dietary calories and fat after controlling for several potential confounding factors. Decreased risk of ACEGC was significantly associated with high ingestion of dietary fiber, lutein, niacin, vitamin B6, iron, and zinc. Higher intakes of vitamin A, beta-carotene, vitamin E, folate,
phosphorus, and potassium were associated with a decreased risk of the disease, but these were not statistically significant. The study suggests that ACEGC can be preventable through dietary interventions.

We have examined the carotenoid contents of several dark green vegetables found to be associated with a lower risk of various epithelial cancers in our
epidemiological study and animal study. Samples of these vegetables were
quantitatively examined by high-performance liquid chromatography (HPLC) on a C-18 reversed-phase column for individual carotenoid content. Pure reference
compounds (alpha-carotene, beta-carotent, lycopene, canthaxanthin, and lutein)
and internal standard (beta-Apo-8'-carotenal) were employed to quantify
xanthophylls and carotenes in these vegetables. The results indicated that
fresh, dark-green, leafy vegetables were high in beta-carotene (0.94-9.36 mg/100 g) and oxygenated carotenoids or xanthophylls, primarily lutein (0.94-7.39 mg/100 g), whereas lycopene and alpha-carotene were not prominent and
canthaxanthin was non existent in these vegetables. These analyses suggest that consumption of carotenoids such as lutein in addition to beta-carotene may be associated with a lower risk of cancers.

We have examined the carotenoid contents of several dark green vegetables found to be associated with a lower risk of various epithelial cancers in our
epidemiological study and animal study. Samples of these vegetables were
quantitatively examined by high-performance liquid chromatography (HPLC) on a C-18 reversed-phase column for individual carotenoid content. Pure reference
compounds (alpha-carotene, beta-carotent, lycopene, canthaxanthin, and lutein)
and internal standard (beta-Apo-8'-carotenal) were employed to quantify
xanthophylls and carotenes in these vegetables. The results indicated that
fresh, dark-green, leafy vegetables were high in beta-carotene (0.94-9.36 mg/100 g) and oxygenated carotenoids or xanthophylls, primarily lutein (0.94-7.39 mg/100 g), whereas lycopene and alpha-carotene were not prominent and
canthaxanthin was non existent in these vegetables. These analyses suggest that consumption of carotenoids such as lutein in addition to beta-carotene may be associated with a lower risk of cancers.

An evaluation of the Health Professionals Follow-Up Study has detected a lower
prostate cancer risk associated with the greater consumption of tomatoes and
related food products. Tomatoes are the primary dietary source of lycopene, a
non-provitamin A carotenoid with potent antioxidant activity. Our goal was to
define the concentrations of lycopene, other carotenoids, and retinol in paired
benign and malignant prostate tissue from 25 men, ages 53 to 74, undergoing
prostatectomy for localized prostate cancer. The concentrations of specific
carotenoids in the benign and malignant prostate tissue from the same subject
are highly correlated. Lycopene and all-trans beta-carotene are the predominant
carotenoids observed, with means SE of 0.80 0.08 nmol/g and 0.54
0.09, respectively. Lycopene concentrations range from 0 to 2.58 nmol/g, and
all-trans beta-carotene concentrations range from 0.09 to 1.70 nmol/g. The 9-cis
beta-carotene isomer, alpha-carotene, lutein, alpha-cryptoxanthin, zeaxanthin,
and beta-cryptoxanthin are consistently detectable in prostate tissue. No
significant correlations between the concentration of lycopene and the
concentrations of any other carotenoid are observed. In contrast, strong
correlations between prostate beta-carotene and alpha-carotene are noted
(correlation coefficient, 0.88; P < 0.0001), as are correlations between several
other carotenoid pairs, which reflects their similar dietary origins. Mean
vitamin A concentration in the prostate is 1.52 nmol/g, with a range of 0.71 to
3.30 nmol/g. We further evaluated tomato-based food products, serum, and
prostate tissue for the presence of geometric lycopene isomers using
high-performance liquid chromatography with a polymeric C30 reversed phase
column. All-trans lycopene accounts for 79 to 91% and cis lycopene isomers for 9 to 21% of total lycopene in tomatoes, tomato paste, and tomato soup. Lycopene concentrations in the serum of men range between 0.60 and 1.9 nmol/ml, with 27 to 42% all-trans lycopene and 58 to 73% cis-isomers distributed among 12 to 13 peaks, depending upon their chromatographic resolution. In striking contrast with foods, all-trans lycopene accounts for only 12 to 21% and cis isomers for 79 to 88% of total lycopene in benign or malignant prostate tissues. cis Isomers of lycopene within the prostate are distributed among 14 to 18 peaks. We conclude that a diverse array of carotenoids are found in the human prostate with significant intra-individual variation. The presence of lycopene in the prostate at concentrations that are biologically active in laboratory studies supports the hypothesis that lycopene may have direct effects within the prostate and contribute to the reduced prostate cancer risk associated with the reduced prostate cancer risk associated with the consumption of tomato-based foods. The future identification and characterization of geometric lycopene isomers may lead to the development of novel agents for chemoprevention studies.

In this review of the scientific literature on the relationship between
vegetable and fruit consumption and risk of cancer, results from 206 human
epidemiologic studies and 22 animal studies are summarized. The evidence for a protective effect of greater vegetable and fruit consumption is consistent for
cancers of the stomach, esophagus, lung, oral cavity and pharynx, endometrium, pancreas, and colon. The types of vegetables or fruit that most often appear to be protective against cancer are raw vegetables, followed by allium vegetables, carrots, green vegetables, cruciferous vegetables, and tomatoes. Substances present in vegetables and fruit that may help protect against cancer, and their mechanisms, are also briefly reviewed; these include dithiolthiones, isothiocyanates, indole-3-carbinol, allium compounds, isoflavones, protease inhibitors, saponins, phytosterols, inositol hexaphosphate, vitamin C, D-limonene, lutein, folic acid, beta carotene, lycopene, selenium, vitamin E, flavonoids, and dietary fiber. Current US vegetable and fruit intake, which averages about 3.4 servings per day, is discussed, as are possible
noncancer-related effects of increased vegetable and fruit consumption,
including benefits against cardiovascular disease, diabetes, stroke, obesity,
diverticulosis, and cataracts. Suggestions for dietitians to use in counseling
persons toward increasing vegetable and fruit intake are presented.

This descriptive, cross-sectional study reports the anti-oxidant activities of a
population sample of 736 individuals, randomly selected from residents of two
small towns of the Latina province of Italy (an area at low frequency of
cancer). The circulating levels of vitamins A, C and E, ceruloplasmin,
carotenoids (lutein + zeaxanthin, lycopene, alpha- and beta-carotene,
cryptoxanthin), cholesterol, high-density lipoprotein cholesterol and
triglycerides, as well as anthropometric measurements (skin-folds, height,
weight) were evaluated. A dietary interview was also performed by means of a
semi-quantitative questionnaire. All the anti-oxidants were above the cut-off
points for normality, whereas body mass index, % fat and serum lipids were not
clearly suggestive of a protected population. The data obtained could be useful
to estimate the baseline values of protective microelements and to assess
dietary profiles in populations following a Mediterranean diet.