Back to the future: the Mediterranean diet paradigm.

The Mediterranean diet was introduced to the scientific community by the classic Seven Countries study. Since then data on the association between this diet and cardiovascular disease, cancer and other chronic diseases have been accumulating. The Mediterranean diet is characterized by a high intake of olive oil, plant products, fish and seafood; a low intake of dairies, meat and meat products; and a moderate ethanol intake. The Mediterranean diet has been operationalized through various computational scores (e.g. the Mediterranean diet score for adults and the KIDMED index for children) which are all based on the dietary components that capture its essence. Next to evidence generated through both observational studies and intervention trials on the inverse association between Mediterranean diet and several risk factors, inflammatory markers and mortality or incidence of disease, there is increasing evidence that Mediterranean populations are abandoning their traditional eating habits. Publications presenting changes over time in the diet of populations participating in the Seven Countries Study point towards an increase in the intake of processed foods and saturated fat and a decrease in the intake of plant foods and monounsaturated fatty acids. Findings are alarming, particularly in relation to younger generations. Studies among children and adolescents in the Mediterranean region clearly indicate that the largest proportions of these populations poorly adhere to their traditional diet. Mediterraneans have clearly not been the major benefactors in the research on the effects of the Mediterranean lifestyle and younger populations in the regions are already following the wrong path.

Impact of thearubigins on the estimation of total dietary flavonoids in the European Prospective Investigation into Cancer and Nutrition (EPIC) study.

Thearubigins (TR) are polymeric flavanol-derived compounds formed during the fermentation of tea leaves. Comprising ∼70% of total polyphenols in black tea, TR may contribute majorly to its beneficial effects on health. To date, there is no appropriate food composition data on TR, although several studies have used data from the US Department of Agriculture (USDA) database to estimate TR intakes. We aimed to estimate dietary TR in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort and assess the impact of including TR or not in the calculation of the total dietary flavonoid intake. Dietary data were collected using a single standardized 24-h dietary recall interviewer-administered to 36 037 subjects aged 35-74 years. TR intakes were calculated using the USDA database. TR intakes ranged from 0.9 mg/day in men from Navarra and San Sebastian in Spain to 532.5 mg/day in men from UK general population. TR contributed <5% to the total flavonoid intake in Greece, Spain and Italy, whereas in the UK general population, TR comprised 48% of the total flavonoids. High heterogeneity in TR intake across the EPIC countries was observed. This study shows that total flavonoid intake may be greatly influenced by TR, particularly in high black tea-consuming countries. Further research on identification and quantification of TR is needed to get more accurate dietary TR estimations.

Dietary intakes and food sources of phytoestrogens in the European Prospective Investigation into Cancer and Nutrition (EPIC) 24-hour dietary recall cohort.

BACKGROUND/OBJECTIVES: Phytoestrogens are estradiol-like natural compounds found in plants that have been associated with protective effects against chronic diseases, including some cancers, cardiovascular diseases and osteoporosis. The purpose of this study was to estimate the dietary intake of phytoestrogens, identify their food sources and their association with lifestyle factors in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. SUBJECTS/METHODS: Single 24-hour dietary recalls were collected from 36,037 individuals from 10 European countries, aged 35-74 years using a standardized computerized interview programe (EPIC-Soft). An ad hoc food composition database on phytoestrogens (isoflavones, lignans, coumestans, enterolignans and equol) was compiled using data from available databases, in order to obtain and describe phytoestrogen intakes and their food sources across 27 redefined EPIC centres. RESULTS: Mean total phytoestrogen intake was the highest in the UK health-conscious group (24.9 mg/day in men and 21.1 mg/day in women) whereas lowest in Greece (1.3 mg/day) in men and Spain-Granada (1.0 mg/day) in women. Northern European countries had higher intakes than southern countries. The main phytoestrogen contributors were isoflavones in both UK centres and lignans in the other EPIC cohorts. Age, body mass index, educational level, smoking status and physical activity were related to increased intakes of lignans, enterolignans and equol, but not to total phytoestrogen, isoflavone or coumestan intakes. In the UK cohorts, the major food sources of phytoestrogens were soy products. In the other EPIC cohorts the dietary sources were more distributed, among fruits, vegetables, soy products, cereal products, non-alcoholic and alcoholic beverages. CONCLUSIONS: There was a high variability in the dietary intake of total and phytoestrogen subclasses and their food sources across European regions.

Olive oil and health: summary of the II international conference on olive oil and health consensus report, Jaén and Córdoba (Spain) 2008.

Olive oil (OO) is the most representative food of the traditional Mediterranean Diet (MedDiet). Increasing evidence suggests that monounsaturated fatty acids (MUFA) as a nutrient, OO as a food, and the MedDiet as a food pattern are associated with a decreased risk of cardiovascular disease, obesity, metabolic syndrome, type 2 diabetes and hypertension. A MedDiet rich in OO and OO per se has been shown to improve cardiovascular risk factors, such as lipid profiles, blood pressure, postprandial hyperlipidemia, endothelial dysfunction, oxidative stress, and antithrombotic profiles. Some of these beneficial effects can be attributed to the OO minor components. Therefore, the definition of the MedDiet should include OO. Phenolic compounds in OO have shown antioxidant and anti-inflammatory properties, prevent lipoperoxidation, induce favorable changes of lipid profile, improve endothelial function, and disclose antithrombotic properties. Observational studies from Mediterranean cohorts have suggested that dietary MUFA may be protective against age-related cognitive decline and Alzheimer's disease. Recent studies consistently support the concept that the OO-rich MedDiet is compatible with healthier aging and increased longevity. In countries where the population adheres to the MedDiet, such as Spain, Greece and Italy, and OO is the principal source of fat, rates of cancer incidence are lower than in northern European countries. Experimental and human cellular studies have provided new evidence on the potential protective effect of OO on cancer. Furthermore, results of case-control and cohort studies suggest that MUFA intake including OO is associated with a reduction in cancer risk (mainly breast, colorectal and prostate cancers).

Dietary beta-carotene, vitamin C and E intake and breast cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC).

So far, studies on dietary antioxidant intake, including beta-carotene, vitamin C and vitamin E, and breast cancer risk are inconclusive. Thus, we addressed this question in the European Prospective Investigation into Cancer and Nutrition. During a median follow-up time of 8.8 years, 7,502 primary invasive breast cancer cases were identified. Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI). All analyses were run stratified by menopausal status at recruitment and, additionally, by smoking status, alcohol intake, use of exogenous hormones and use of dietary supplements. In the multivariate analyses, dietary intake of beta-carotene, vitamin C and E was not associated with breast cancer risk in premenopausal [highest vs. lowest quintile: HR, 1.04 (95% CI, 0.85-1.27), 1.12 (0.92-1.36) and 1.11 (0.84-1.46), respectively] and postmenopausal women [0.93 (0.82-1.04), 0.98 (0.87-1.11) and 0.92 (0.77-1.11), respectively]. However, in postmenopausal women using exogenous hormones, high intake of beta-carotene [highest vs. lowest quintile; HR 0.79 (95% CI, 0.66-0.96), P (trend) 0.06] and vitamin C [0.88 (0.72-1.07), P (trend) 0.05] was associated with reduced breast cancer risk. In addition, dietary beta-carotene was associated with a decreased risk in postmenopausal women with high alcohol intake. Overall, dietary intake of beta-carotene, vitamin C and E was not related to breast cancer risk in neither pre- nor postmenopausal women. However, in subgroups of postmenopausal women, a weak protective effect between beta-carotene and vitamin E from food and breast cancer risk cannot be excluded.

Use of dietary supplements in the European Prospective Investigation into Cancer and Nutrition calibration study.

BACKGROUND: Dietary supplement use is increasing, but there are few comparable data on supplement intakes and how they affect the nutrition and health of European consumers. The aim of this study was to describe the use of dietary supplements in subsamples of the 10 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC). METHODS: Specific questions on dietary supplement use were asked as a part of single 24-h recalls performed on 36,034 men and women aged 35-74 years from 1995 to 2000. RESULTS: Between countries, the mean percentage of dietary supplement use varied almost 10-fold among women and even more among men. There was a clear north-south gradient in use, with a higher consumption in northern countries. The lowest crude mean percentage of use was found in Greece (2.0% among men, 6.7% among women), and the highest was in Denmark (51.0% among men, 65.8% among women). Use was higher in women than in men. Vitamins, minerals or combinations of them were the predominant types of supplements reported, but there were striking differences between countries. CONCLUSIONS: This study indicates that there are wide variations in supplement use in Europe, which may affect individual and population nutrient intakes. The results underline the need to monitor consumption of dietary supplements in Europe, as well as to evaluate the risks and benefits.

Plasma phyto-oestrogens and prostate cancer in the European Prospective Investigation into Cancer and Nutrition.

We examined plasma concentrations of phyto-oestrogens in relation to risk for subsequent prostate cancer in a case-control study nested in the European Prospective Investigation into Cancer and Nutrition. Concentrations of isoflavones genistein, daidzein and equol, and that of lignans enterolactone and enterodiol, were measured in plasma samples for 950 prostate cancer cases and 1042 matched control participants. Relative risks (RRs) for prostate cancer in relation to plasma concentrations of these phyto-oestrogens were estimated by conditional logistic regression. Higher plasma concentrations of genistein were associated with lower risk of prostate cancer: RR among men in the highest vs the lowest fifth, 0.71 (95% confidence interval (CI) 0.53-0.96, P trend=0.03). After adjustment for potential confounders this RR was 0.74 (95% CI 0.54-1.00, P trend=0.05). No statistically significant associations were observed for circulating concentrations of daidzein, equol, enterolactone or enterodiol in relation to overall risk for prostate cancer. There was no evidence of heterogeneity in these results by age at blood collection or country of recruitment, nor by cancer stage or grade. These results suggest that higher concentrations of circulating genistein may reduce the risk of prostate cancer but do not support an association with plasma lignans.

Mediterranean diet and longevity.

While several investigations have focused on the association between individual foods and nutrients upon the development of chronic diseases, few have examined the role that entire dietary patterns may play in health and disease. A dietary pattern generally considered to have beneficial health effects is that of the Mediterranean diet. In this paper, five cohort studies exploring the association of Mediterranean diet with overall mortality and hence longevity are reviewed. A number of conclusions can be drawn. First, there appears to exist sufficient evidence that diet does indeed influence longevity. Secondly, an optimal diet for the prevention of both coronary heart disease and cancer is likely to extensively overlap with the traditional Mediterranean diet. It is not yet clear which components in the Mediterranean diet are more important for its apparent health effects, but olive oil, plant foods and moderate wine consumption are likely candidates.

Plasma carotenoid levels in relation to the Mediterranean diet in Greece.

In the context of the Greek segment of the European Prospective Investigation into Cancer and Nutrition (EPIC), we conducted a cross-sectional study to examine the effects of the intake of plant foods central in the traditional Mediterranean diet on plasma levels of alpha-carotene, beta-carotene, lycopene, beta-cryptoxanthin, and lutein-zeaxanthin. Study subjects were a random sample of 45 men and 68 women, aged 30-82 years, from the Greek EPIC cohort of 27,953 volunteers. Linear regression models were fitted, with the carotenoid blood levels as dependent variables. Independent variables were selected food items, as well as body mass index, controlling for energy intake and a set of demographic factors. Body mass index was inversely associated with plasma levels of the studied carotenoids. The association was highly significant for alpha-carotene and beta-carotene, significant for lutein-zeaxanthin, and borderline significant (p approximately 0.07) for lycopene. Tomato intake was significantly positively associated with plasma lycopene, and beta-carotene. Other fruity vegetables and non-fruity vegetables were significantly positively associated, the former with alpha-carotene and the latter with both alpha- and beta-carotene plasma levels. Fruits showed a highly significant positive association with plasma beta-cryptoxanthin, as well as with beta-carotene. No association was found between the intake of olive oil or other added lipids and plasma carotenoids. We conclude that among the studied components of the Mediterranean diet, fruits and vegetables tend to increase levels of some carotenoids, but olive oil has no apparent effect.

Mediterranean diet: the past and the present.

Mortality statistics from the World Health Organization have provided early evidence that diet in the Mediterranean countries has been affecting the health of the respective populations and, in particular, their coronary health. Keys (1) has taken the lead arguing that the traditional Mediterranean diet has beneficial effects on health. Recent studies, capturing the evidence accumulated over the last three decades, have documented that the traditional Mediterranean diet meets several important criteria for a healthy diet. An attempt to conceptualize the proper diet and to make it able to function has been reported and a score has been developed and evaluated. Studies among the elderly in Greece, Denmark, Australia, Spain and China have shown that the overall Mediterranean dietary pattern was more important for longevity than single nutrients. These findings suggest, therefore, that a Mediterranean diet is associated with longer survival. Two additional questions should be addressed at this time: Is the Mediterranean diet an integral entity, or the sum of identifiable components that can and should be separately considered in the development of guidelines? Is the Mediterranean diet or its major components transferable to populations living far from the Mediterranean area? Answers to these questions would be important for scientific and policy reasons. The dietary patterns that prevail in the Mediterranean area have many common characteristics, most of which stem from the fact that olive oil plays an important role in all of them. Thus, although different regions in the Mediterranean basin have their own diets, it is legitimate to consider them as variants of a single entity, the Mediterranean diet. The Mediterranean diet can be described as the dietary pattern found in the olive growing areas of the Mediterranean region, in the late '50s and early '60s, when the consequences of World War II were overcome, but the fast-food culture had not reached the area yet (2). Olive oil is important both because of its several beneficial properties and because it allows the consumption of large quantities of vegetables and legumes in the form of salads and of cooked foods. Other essential components of the Mediterranean diet are wheat, grapes, and their derived products. Total lipid consumption may be high, around 40% of total energy intake as in Greece, or moderate, around 30% of total energy intake as in Italy. In all instances, however, the ratio of monounsaturated to saturated dietary lipids is much higher than in other places of the world, including northern Europe and North America (3).

Cancer and Mediterranean dietary traditions.

The incidence of cancer overall in Mediterranean countries is lower than in Scandinavian countries, the United Kingdom, and the United States. This is mostly accounted for by the lower incidence among Mediterranean countries of cancer of the large bowel, breast, endometrium, and prostate. These forms of cancer have been linked to dietary factors, particularly low consumption of vegetables and fruit, and to a certain extent, high consumption of meat. The traditional Mediterranean diet is characterized by high consumption of foods of plant origin, relatively low consumption of red meat, and high consumption of olive oil, which in several studies has been reported to be more beneficial against cancer than other forms of added lipids. By taking into account the established or presumed nutritional causation of major forms of cancer and the composition of the traditional Mediterranean diet, estimates can be derived concerning the fraction of cancer occurrence in highly developed Western countries that could be attributed to their diets in comparison with the healthy traditional Mediterranean diet. Although estimates can only be crude, it can be calculated that up to 25% of the incidence of colorectal cancer, approximately 15% of the incidence of breast cancer, and approximately 10% of the incidence of prostate, pancreas, and endometrial cancer could be prevented if the populations of highly developed Western countries could shift to the traditional healthy Mediterranean diet.

Mediterranean diet and longevity.

Mortality statistics from the WHO database covering the period 1960 to 1990 have provided intriguing evidence that something unusual has been affecting in a beneficial way the health of the Mediterranean population. In recent papers, which evaluated the evidence accumulated over the last three decades, it was concluded that the traditional Mediterranean diet meets several important criteria for a healthy diet. Direct evidence in support of the beneficial properties of the Mediterranean diet has also become available. These data were derived from three studies, which have used a diet score, devised a priori on the basis of eight desirable key features of the traditional common diet in the Mediterranean region. The conclusion of these studies is that a diet that adheres to the principles of the traditional Mediterranean one is associated with longer survival. The Greek version of the Mediterranean diet is dominated by the consumption of olive oil and by high consumption of vegetables and fruits. Antioxidants represent a common element in these foods and an antioxidant action provides a plausible explanation for the apparent benefits. Wild edible greens frequently eaten in rural Greece in the form of salads and pies contain very high quantities of flavonoids-- considerably higher than those found in red wine or black tea. While there is no direct evidence that these antioxidants are central to the benefits of the Mediterranean Diet, indirect evidence from epidemiological data and the increasing understanding of their mechanisms of action suggest that antioxidants may play a major role.

Energy intake and monounsaturated fat in relation to bone mineral density among women and men in Greece.

BACKGROUND: Several variables have been established as risk factors for osteoporosis: it is more common among women and the gender difference increases with age and with years since menopause. Estrogens, androgens, physical activity, and body mass index have been previously shown to be positively associated with bone mineral density and inversely with risk for fractures. METHODS: To assess the effect on bone mineral content of energy-generating nutrients, healthy men (n = 36) and women (n = 118) ages 25-69 years were interviewed among visitors and staff of the University of Athens Department of Medical Physics. Bone mineral density (BMD) was measured by single photon absorptiometry. RESULTS: Demographic and lifestyle variables were not significantly related to BMD in this study, although the patterns were consistent with those previously reported by other investigators. Total energy intake, which also reflects energy expenditure through physical activity, was positively associated with BMD among both men (P = 0.003) and women (P = 0.04). After adjustment for nonnutritional variables and energy intake, monounsaturated fat, which in the Greek population is mostly derived from olive oil, was associated with BMD. The association was positive among both men (P = 0.01) and women (P = 0.03). There was evidence for an inverse association between carbohydrate intake and BMD, but the association was significant only with respect to mono- and disaccharides. CONCLUSIONS: In this population, consumption of monounsaturated fat and physical activity were predictive of bone mineral density, but larger studies are needed.

Computed and chemically determined nutrient content of foods in Greece. The Foods and Nutrients Working Group.

Energy-generating nutrients and total energy were computed and analytically determined for four widely used foods in Greece (mousaka, bean soup, infant food, and feta cheese), as well as for the individual food items necessary for their preparation. Standard procedures were used for chemical analyses, whereas computed values were generated through the Unilever Dietary Analysis Program--UNIDAP (Barrow et al., 1988) on the basis of the British food composition tables. Pesticides and pesticide residues were also determined in the studied samples. A very good agreement was noted with respect to the nutrient composition of the four prepared foods, whereas the agreement was somewhat weaker for the individual food items used for the preparation of the composite foods. It is concluded that the UNIDAP program generates reliable nutrient composition data for composite foods and for time integrated dietary intakes in Greece. The concentrations of several of the determined pesticides were towards the higher end of the spectrum of levels reported in the literature. This project has demonstrated the value of collaboration between academic institutions, industry, and state laboratories towards the development and validation of food composition databases.

Consumption of olive oil and specific food groups in relation to breast cancer risk in Greece.

BACKGROUND: Experimental animal studies suggest that olive oil consumption, as contrasted to consumption of other fat types, does not enhance the occurrence of chemically induced mammary tumors, but human data are sparse. Furthermore, evidence is inconclusive concerning the role of food groups, as distinct from that of major nutrients, in the etiology of breast cancer in women. PURPOSE: This analysis was conducted to evaluate and quantify the effect of consumption of olive oil, margarine, and a range of food groups on the risk of breast cancer. METHODS: Data from a comprehensive, semiquantitative food-frequency questionnaire administered to 820 women with breast cancer and 1548 control women from the study base were used to calculate odds ratios (ORs) and X statistics of linear trend for the consumption of olive oil, margarine, and a series of food groups classified in quintiles. Adjustment for the effects of reproductive risk factors, energy intake, and mutual confounding influences was implemented through unconditional logistic regression modeling. RESULTS: Vegetable consumption and fruit consumption were independently associated with statistically significant reductions of breast cancer risk by 12% and 8%, respectively, per quintile increase; no significant associations were evident for the other food groups examined. Increased olive oil consumption was associated with significantly reduced breast cancer risk (OR = 0.75 [95% confidence interval = 0.57-0.98] for more than once a day versus once a day), whereas increased margarine consumption was associated with significantly increased risk (OR = 1.05 [95% confidence interval = 1.00-1.10] for an increment of four times a month). The olive oil association was apparently concentrated among postmenopausal women, but the relevant interaction term was not statistically significant; there was no suggestion of interaction with menopausal status for consumption of either vegetables, fruits, or margarine. CONCLUSIONS: Although major categories of macronutrients do not show significant associations with breast cancer risk in most studies, including the present one, vegetables and fruits are inversely, significantly, and strongly associated with this risk. There also is evidence that olive oil consumption may reduce the risk of breast cancer, whereas margarine intake appears to be associated with an elevated risk for the disease.

The association of fat and other macronutrients with breast cancer: a case-control study from Greece.

The Greek diet is characterized by a high total fat but low saturated fat intake. In a hospital-based case-control study of female breast cancer conducted in Athens (1989-91), 820 patients with confirmed cancer of the breast were compared with 795 orthopaedic patient controls and 753 hospital visitor controls, matched to the cases by age and interviewer. Diet was ascertained through a semiquantitative food frequency questionnaire; macronutrient intakes were estimated from the nutrient content of a selected typical portion size for each specified food item, summed for all items. Logistic regression was used to analyse the data, controlling for demographic and reproductive risk factors for breast cancer as well as for total energy intake and mutual confounding influences among nutrients. There was no significant or suggestive association of total protein, total fat, categories of fat or total carbohydrates with breast cancer risk. Thus, the mutually adjusted relative risk per quintile and (in parenthesis) 95% confidence interval were: for protein, 1.06 (0.94-1.20); saturated fat, 0.99 (0.89-1.11); monounsaturated fat, 0.97 (0.88-1.07), polyunsaturated fat, 1.05 (0.97-1.13); and total carbohydrates, 1.03 (0.94-1.12). In alternative analytical approaches only total protein appeared to be positively associated to the occurrence of breast cancer with some consistency, but the results were far from statistically significant. These findings do not support a role for fat or other energy-generating nutrients in the aetiology of breast cancer.