Life Extension Magazine

Life Extension Magazine May 2008

Abstracts

Mediterranean Diet

Adherence to the mediterranean diet is inversely associated with circulating interleukin-6 among middle-aged men: a twin study.

BACKGROUND: The Medite-rranean diet is protective against cardiovascular disease; a proposed mechanism is through a reduction in systemic inflammation. It is unknown to what extent the association between the Mediterranean diet and inflammation is due to genetic or other familial factors. METHODS AND RESULTS: We administered the Willett food frequency questionnaire to 345 middle-aged male twins and assessed adherence to the Mediterranean diet using a published adherence score. Fasting plasma levels of interleukin-6, C-reactive protein, and known cardiovascular risk factors were measured. Mixed-effect regression analyses were used to examine the relationship between diet score and inflammatory biomarkers after accounting for known cardiovascular risk factors. Adherence to the Mediterranean diet was associated with reduced levels of interleukin-6 (P<0.001) but not C-reactive protein (P=0.10) after adjustment for total energy intake, other nutritional factors, known cardiovascular risk factors, and use of supplements and medications. When the overall association of adherence to the diet with interleukin-6 levels was partitioned into between- and within-pair effects, the between-pair effect was not significant (P=0.9) and the within-pair effect was highly significant (P<0.0001). A 1-unit within-pair absolute difference in the diet score was associated with a 9% (95% CI, 4.5 to 13.6) lower interleukin-6 level. CONCLUSIONS: Shared environmental and genetic factors are unlikely to play a major role in the association between adherence to the Mediterranean diet and systemic inflammation. These results support the hypothesis that reduced inflammation is an important mechanism linking Mediterranean diet to reduced cardiovascular risk.

Circulation. 2008 Jan 15;117(2):169-75

The relationship between adherence to the Mediterranean diet and the severity and short-term prognosis of acute coronary syndromes (ACS): The Greek Study of ACS (The GREECS).

BACKGROUND:Although adherence to the Mediterranean diet has long been associated with lower incidence of various chronic diseases among apparently healthy individuals, its relationship with the severity and short prognosis (30 d) of patients with cardiovascular disease has rarely been investigated. OBJECTIVE: We sought to evaluate the association between adherence to the Mediterranean diet and the severity and prognosis of acute coronary syndromes. METHODS: From October 2003 to September 2004, a sample of 6 hospitals located in several urban and rural Greek regions was selected, and almost all survivors after an acute coronary syndrome were enrolled into the study (2,172 patients were included in the study; 76% were men and 24% women). Adherence to the Mediterranean diet was assessed by a diet score that incorporated the inherent characteristics of this diet. Higher values of the score (range 0-55) were closer to the Mediterranean diet. Biochemical indices of myocardial damage were also considered. RESULTS: Diet score was inversely correlated with entry values of cardiac troponin I (rho = -0.19, P < 0.001), creatine phosphokinase (rho = -0.09, P < 0.001), and creatine phosphokinase-MB (rho = -0.09, P < 0.001). An increment in the diet score was associated with significant decrease in troponin I and creatine phosphokinase-MB levels (P < 0.01) after adjusting for various potential confounders. Moreover, diet score was associated with lower risk of recurrent events (odds ratio = 0.81, 95% confidence interval 0.61-0.98). However, this association became insignificant when the discharge diagnosis of the patients was taken into account. CONCLUSION: Background dietary habits close to the Mediterranean diet seem to be associated with lower severity of coronary heart disease.

Nutrition. 2006 Jul-Aug;22(7-8):722-30

Mediterranean dietary pattern and prediction of all-cause mortality in a US population: results from the NIH-AARP Diet and Health Study.

BACKGROUND: The Medite-rranean diet has been suggested to play a beneficial role for health and longevity. However, to our knowledge, no prospective US study has investigated the Mediterranean dietary pattern in relation to mortality. METHODS: Study participants included 214,284 men and 166,012 women in the National Institutes of Health (NIH)-AARP (formerly known as the American Association of Retired Persons) Diet and Health Study. During follow-up for all-cause mortality (1995-2005), 27,799 deaths were documented. In the first 5 years of follow-up, 5,985 cancer deaths and 3,451 cardiovascular disease (CVD) deaths were reported. We used a 9-point score to assess conformity with the Mediterranean dietary pattern (components included vegetables, legumes, fruits, nuts, whole grains, fish, monounsaturated fat-saturated fat ratio, alcohol, and meat). We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) using age- and multivariate-adjusted Cox models. RESULTS: The Mediterranean diet was associated with reduced all-cause and cause-specific mortality. In men, the multivariate HRs comparing high to low conformity for all-cause, CVD, and cancer mortality were 0.79 (95% CI, 0.76-0.83), 0.78 (95% CI, 0.69-0.87), and 0.83 (95% CI, 0.76-0.91), respectively. In women, an inverse association was seen with high conformity with this pattern: decreased risks that ranged from 12% for cancer mortality to 20% for all-cause mortality (P = .04 and P < .001, respectively, for the trend). When we restricted our analyses to never smokers, associations were virtually unchanged. CONCLUSION: These results provide strong evidence for a beneficial effect of higher conformity with the Mediterranean dietary pattern on risk of death from all causes, including deaths due to CVD and cancer, in a US population.

Arch Intern Med. 2007 Dec 10;167(22):2461-8

Effect of a traditional Mediterranean diet on lipoprotein oxidation: a randomized controlled trial.

BACKGROUND: Despite the richness in antioxidants of the Mediterranean diet, to our knowledge, no randomized controlled trials have assessed its effect on in vivo lipoprotein oxidation. METHODS: A total of 372 subjects at high cardiovascular risk (210 women and 162 men; age range, 55-80 years), who were recruited into a large, multicenter, randomized, controlled, parallel-group clinical trial (the Prevención con Dieta Mediterránea [PREDIMED] Study) directed at testing the efficacy of the traditional Mediterranean diet (TMD) on the primary prevention of coronary heart disease, were assigned to a low-fat diet (n = 121) or one of 2 TMDs (TMD + virgin olive oil or TMD + nuts). The TMD participants received nutritional education and either free virgin olive oil for all the family (1 L/wk) or free nuts (30 g/d). Diets were ad libitum. Changes in oxidative stress markers were evaluated at 3 months. RESULTS: After the 3-month interventions, mean (95% confidence intervals) oxidized low-density lipoprotein (LDL) levels decreased in the TMD + virgin olive oil (-10.6 U/L [-14.2 to -6.1]) and TMD + nuts (-7.3 U/L [-11.2 to -3.3]) groups, without changes in the low-fat diet group (-2.9 U/L [-7.3 to 1.5]). Change in oxidized LDL levels in the TMD + virgin olive oil group reached significance vs that of the low-fat group (P = .02). Malondialdehyde changes in mononuclear cells paralleled those of oxidized LDL. No changes in serum glutathione peroxidase activity were observed. CONCLUSIONS: Individuals at high cardiovascular risk who improved their diet toward a TMD pattern showed significant reductions in cellular lipid levels and LDL oxidation. Results provide further evidence to recommend the TMD as a useful tool against risk factors for CHD.

Arch Intern Med. 2007 Jun 11;167(11):1195-203

A pilot study of a Mediterranean-type diet intervention in female patients with rheumatoid arthritis living in areas of social deprivation in Glasgow.

BACKGROUND: A Medite-rranean-type diet rich in fish, fruit and vegetables and low in saturated fats has been associated with health benefits, including improved cardiovascular profile and benefit in RA. OBJECTIVE: To overcome obstacles to healthy eating by a community-based intervention promoting a Mediterranean-type diet in patients with RA living in socially deprived areas of Glasgow. METHODS: 130 female patients with RA aged 30-70 years (median 55), disease duration 8 years were recruited from three hospital sites. The intervention group (n = 75) attended weekly 2-hour sessions for 6 weeks in the local community, including hands-on cooking classes backed up with written information. The control group (n = 55) were given dietary written information only. Both groups completed food frequency questionnaires (FFQs), and clinical and laboratory measures were assessed at baseline, 3 and 6 months. RESULTS: Significant benefit was shown in the intervention group compared with controls for patient global assessment at 6 months (p = 0.002), pain score at 3 and 6 months (p = 0.011 and 0.049), early morning stiffness at 6 months (p = 0.041) and Health Assessment Questionnaire score at 3 months (p = 0.03). Analysis of the FFQs showed significant increases in weekly total fruit, vegetable and legume consumption and improvement in the ratio of monounsaturated:saturated fat intake and systolic BP in the intervention group only. The cooking classes were positively received by patients and tutors; cost/patient for the 6 week course was 84 pounds (124 euro). CONCLUSIONS: Results demonstrate that a 6 week intervention can improve consumption of healthier foods. If implemented more widely it may prove a popular, inexpensive and useful adjunct to other RA treatment.

Ann Rheum Dis. 2007 Sep;66(9):1239-43

There are many Mediterranean diets.

Interest in Mediterranean diet began 30 years ago, when Ancel Keys published the results of the famous Seven Countries Study, Since 1945, almost 1.3 million people have come to Australia from Mediterranean countries as new settlers. There are 18 countries with coasts on the Mediterranean sea: Spain, southern France, Italy, Malta, Croatia, Bosnia, Albania, Greece, Cyprus, Turkey, Syria, Lebanon, Egypt, Libya, Malta, Tunisia, Algeria, and Morocco. This study from which this report derives aims to investigate the influence of the food habits of immigrants from Mediterranean countries on Australian food intake. Here we look at the ‘traditional’ food habits of the above Mediterranean countries as told by 102 people we interviewed in Sydney, who came from 18 Mediterranean countries to Sydney. Most of the informants were women, their age ranged from 35 to 55 years. The interview was open-ended and held in the informant’s home. It usually lasted around 1 1/2 hours. The interview had three parts. Personal information was obtained, questions relating to the food habits of these people back in their original Mediterranean countries and how their food intake and habits have changed in Australia were also asked. From the interviews, we have obtained a broad picture of ‘traditional’ food habits in different Mediterranean countries. The interview data was checked with books of recipes for the different countries. While there were similarities between the countries, there are also important differences in the food habits of the Mediterranean countries. Neighbouring countries’ food habits are closer than those on opposite sides of the Mediterranean Sea. We suggest that these food habits can be put into four groups. The data here refer to food habits in Mediterranean countries 20 or 30 years ago, as they were recovering from the Second World War. There is no single ideal Mediterranean diet. Nutritionists who use the concept should qualify the individual country and the time in history of their model Mediterranean diet.

Asia Pac J Clin Nutr. 2001;10(1):2-9

Association of drinking pattern and alcohol beverage type with the prevalence of metabolic syndrome, diabetes, coronary heart disease, stroke, and peripheral arterial disease in a Mediterranean cohort.

The purpose of this study was to investigate the relationship between alcohol consumption and the prevalence of the metabolic syndrome (MetS), type 2 diabetes mellitus (DM), coronary heart disease (CHD), stroke, peripheral arterial disease (PAD), and overall cardiovascular disease (CVD) in a Mediterranean cohort. It consisted of a cross-sectional analysis of a representative sample of Greek adults (n = 4,153) classified as never, occasional, mild, moderate, or heavy drinkers. Cases with overt CHD, stroke, or PAD were recorded. In our population, 17% were never, 23% occasional, 27% mild, 24% moderate, and 9% heavy drinkers. Moderate alcohol consumption was associated with a lower trend for the prevalence of the MetS (P = .0001), DM (P < .0001), CHD (P = .0002), PAD (P = .005), and overall CVD (P = .001) but not stroke compared with no alcohol use. Heavy drinking was associated with an increase in the prevalence of all of these disease states. Wine consumption was associated with a slightly better effect than beer or spirits consumption on the prevalence of total CVD, and beer consumption was associated with a better effect than spirits consumption. Alcohol intake was positively related with body weight, high-density lipoprotein cholesterol levels, and hypertension. Moderate alcohol consumption is associated with a lower prevalence of the MetS, DM, PAD, CHD, and overall CVD but not stroke compared with no alcohol use in a Mediterranean population. Heavy drinking was associated with an increase in the prevalence of all of these disease states. Advice on alcohol consumption should probably mainly aim at reducing heavy drinking.

Angiology. 2007 Dec-2008 Jan;58(6):689-97

The association between adherence to the Mediterranean diet and fasting indices of glucose homoeostasis: the ATTICA Study.

OBJECTIVE: We investigated the association between adherence to Mediterranean diet and fasting indices of glucose homoeostasis, in a Greek adult population. METHODS: During 2001-2002 we randomly enrolled 1,514 men and 1,528 women (18-89 years old) without history of CVD, from the Attica area. Diabetes mellitus (type 2) and impaired fasting glucose (IFG) were defined according to the established ADA criteria. Insulin resistance was evaluated by HOMA-IR. Dietary habits were assessed through a validated food frequency questionnaire and a diet score (range 0-55) was developed (higher values means greater adherence to the Mediterranean diet). RESULTS: The overall prevalence of diabetes type 2 was 7.9% in men and 6.0% in women (P = 0.05). Mean diet score was 26.3 +/- 6.8 in normoglycemic, 25.7 +/- 6.4 in IFG and 22.2 +/- 5.8 in diabetic subjects (p < 0.001). In normoglycemic subjects who were in the upper tertile of the diet score we observed 7% lower glucose (p < 0.05), 5% lower insulin (p < 0.05) and 15% lower HOMA-IR (p < 0.01) levels compared to subjects in the lower tertile of the diet score. Additionally, in diabetic/IFG participants who where in the upper tertile of the diet score we observed 15% lower glucose (p < 0.05), 15% lower insulin (p < 0.05) and 27% lower HOMA-IR (p < 0.01) levels compared to those in the lower tertile. However, multiple regression analysis, adjusted for age, sex, BMI, waist-to-hip ratio, physical activity, smoking status, and presence of hypertension and hypercholesterolemia, confirmed the previous associations in normoglycemic, but not in diabetic/IFG people. CONCLUSION: An inverse association was observed between adherence to Mediterranean diet and indices of glucose homeostasis, only in normoglycemic people.

J Am Coll Nutr. 2007 Feb;26(1):32-8

Association between the prevalence of obesity and adherence to the Mediterranean diet: the ATTICA study.

OBJECTIVE: We evaluated the prevalence of obesity in relation to adherence to a Mediterranean diet. METHODS: We conducted a cross-sectional survey that randomly enrolled 1,514 men (18 to 87 y old) and 1,528 women (18 to 89 y old) with no history of cardiovascular disease. Anthropometric indices were measured and frequency of various foods consumed during a usual week was recorded. Adherence to a Mediterranean diet was assessed by a diet score that incorporated the inherent characteristics of this diet. RESULTS: Prevalences of overweight and obesity were 53% and 20% in men and 31% and 15% in women. An inverse relation was observed between diet score, waist-to-hip ratio (r = -0.31, P < 0.001), and body mass index (r = -0.4, P < 0.001) after adjusting for sex and age. Greater adherence to the Mediterranean diet (i.e., highest tertile) was associated with a 51% lower odds of being obese (odds ratio 0.49, 95% confidence interval 0.42 to 0.56) and a 59% lower odds of having central obesity (odds ratio 0.41, 95% confidence 0.35 to 0.47) compared with a non-Mediterranean diet (i.e., lowest tertile) after controlling for age, sex, physical activity status, metabolism, and other variables. CONCLUSION: We observed an inverse relation between adherence to a Mediterranean dietary pattern and prevalence of obesity in a free-eating, population-based sample of men and women, irrespective of various potential confounders.

Nutrition. 2006 May;22(5):449-56

Mediterranean diet and insulin sensitivity, lipid profile and blood pressure levels, in overweight and obese people; the Attica study.

BACKGROUND: We aimed to investigate if overweight and obese adults “close” to Mediterranean diet present better insulin, lipids profile and better pressure levels, compared to individuals close to a more Westernized diet. METHODS: The ATTICA study is a population-based cohort that has randomly enrolled 3,042 adult men and women, stratified by age - gender, from the greater area of Athens, during 2001-2002. Of them, in this work were have studied 1,762 participants with excess body weight, meaning overweight (BMI: 25-29.9 kg/m2) and obese (BMI>30 kg/m2). 1,064 were men and 698 women (20-89 years old). Adherence to Mediterranean diet was assessed through a diet-score that was based on a validated food-frequency questionnaire. Blood pressure was measured and also fasting glucose, insulin and blood lipids. Insulin sensitivity was also assessed by the homeostasis model assessment (HOMA) approach (glucose x insulin/22.5). RESULTS: Individuals with excess bodyweight in the highest tertile of diet score, were more insulin sensitive than those in the lowest tertile (11.4% lower HOMA, p = 0.06), had 13% lower levels of total cholesterol (p = 0.001) and 3 mmHg decrease of systolic blood pressure levels (p < 0.001), when adjusted for age, sex and BMI. Multivariate analysis after taking into account several confounders demonstrated that insulin sensitivity, total cholesterol and systolic blood pressure were independently but only modestly correlated with Mediterranean diet in people with excess bodyweight. CONCLUSION: Adherence to Mediterranean diet is modestly associated with a better insulin sensitivity, lower levels of total cholesterol and lower levels of systolic blood pressure in overweight and obese subjects. This may suggest that compared to general population, the beneficial effect of this diet in cardiovascular system of excess body weight people is limited.

Lipids Health Dis. 2007 Sep 19;6:22

Mediterranean diet and the metabolic syndrome.

The metabolic syndrome (also referred to as syndrome X or the insulin resistance syndrome) has emerged as an important cluster of risk factors for atherosclerotic disease. Patients with the syndrome also are at increased risk for developing type 2 diabetes mellitus. Common features are central (abdominal) obesity, insulin resistance, hypertension, and dyslipidemia. Weight reduction deserves first priority in individuals with abdominal obesity and the metabolic syndrome. Both weight reduction and maintenance of a lower weight are best achieved by a combination of reduced caloric intake and increased physical activity. Dietary patterns close to the Mediterranean diet and rich in fruit and vegetables, and high in monounsaturated fats are negatively associated with features of the metabolic syndrome. Some recent studies dealing specifically with the effect of interventions on the resolution of the metabolic syndrome have demonstrated a 25% net reduction in the prevalence of the syndrome following lifestyle changes mainly based on nutritional recommendations. Similar rates of resolution have been obtained with drugs, such as rosiglitazone and rimonabant. The favourable benefit/hazard ratio makes Mediterranean-style diets particularly promising to reduce the cardiovascular burden associated with the metabolic syndrome.

Mol Nutr Food Res. 2007 Oct;51(10):1268-74

Mediterranean diet and osteoporosis prevention.

As a result of the demographic shift towards an ageing population, all industrialized countries face a growing prevalence of chronic age-related conditions, particularly osteoporosis. This multifaceted disease is defined as “a systemic skeletal disorder” characterized by low bone mass and micro-architectural deterioration of bone tissue, which results in increased bone fragility and susceptibility to fracture. Two main categories have been suggested: post-menopausal and senile osteoporosis. The prevention of osteoporosis through dietary means is especially challenging in technologically advanced societies. Indeed, within Europe, conspicuous differences are encountered in the severity of osteoporosis, the lowest incidence being reported in the Mediterranean area. The beneficial effect is attributed mainly to specific eating pattern. These food items contain a complex array of naturally occurring bioactive molecules with antioxidant, anti-inflammatory and alkalinising properties, that may contribute to the bone-sparing effect of Mediterranean diet.

Med Sci (Paris). 2007 Aug-Sep;23(8-9):756-60

Mediterranean diet in relation to body mass index and waist-to-hip ratio.

OBJECTIVE: The Medite-rranean diet is rich in fat and starch, and hence may be related to overweight. We therefore investigated the relationship between adherence to a Mediterranean diet and body mass index (BMI) and waist-to-hip ratio (WHR). DESIGN AND SETTING: Data were obtained from the control group of a network of case-control studies on cancer conducted in major teaching and general hospitals in four Italian areas between 1991 and 2002. An interviewer-administered validated 78-item food-frequency questionnaire was used to obtain information on the subjects’ habitual diet. Information on socio-economic factors, lifestyle habits and anthropometric measures was also collected. A Mediterranean diet score (MDS) was derived on the basis of eight characteristics of the Mediterranean diet. SUBJECTS: Subjects were 6,619 patients (3,090 men, 3,529 women) admitted to hospital for a wide spectrum of acute, non-neoplastic conditions, unrelated to known risk factors for cancer and long-term modifications of diet. RESULTS: In multiple linear regression models adjusted for age, study centre, education, tobacco smoking, occupational physical activity and total energy intake, the MDS was not related to BMI (beta = 0.05 for men and -0.04 for women) or WHR (beta = 0.000 and 0.001, respectively) in both sexes. CONCLUSIONS: Adherence to the major characteristics of the Mediterranean diet is unrelated to BMI and WHR, confirming previous data from Greece and Spain.

Public Health Nutr. 2008 Feb;11(2):214-7