Mediterraan dieet voor een langer leven*
Uit een studie onder ruim 28.000 Grieken blijkt dat een mediterraan dieet goed is voor een lang en gezond leven. De Grieken in de leeftijd van 20 tot 86 jaar werden 8½ jaar gevolgd. In die periode stierven 1.075 deelnemers. Slechts 39% daarvan waren deelnemers die zich het best aan een mediterraan dieet hielden tegen 61% die zich het slechts aan een mediterraan dieet hielden. Een mediterraan dieet bestaat hoofdzakelijk uit weinig vlees, veel groenten, fruit, noten, olijfolie en het gematigd drinken van wijn. Als gekeken werd naar de verschillende bestanddelen in het dieet bleken die ook een verschillende lagere kans op sterven te geven. Het gematigd drinken van wijn tijdens de maaltijd gaf een lager percentage van 23,5, weinig vlees gaf 16,6%, veel groenten 16,6%, fruit en noten 11,2%, veel olijfolie 10,6% en veel peulen en bonen 9,7%.
Moderate Wine, Little Meat, Many Vegetables May Be Key Mediterranean Diet Items Linked to Longer Life
A population-based cohort study of individuals in Greece has teased out items in the Mediterranean diet that appear to contribute to the increased longevity associated with this diet [1].
The largest effects on reduced mortality came from drinking moderate amounts of alcohol, eating little meat, eating lots of vegetables, eating fruits and nuts, and using olive oil. However, the individual components of the Mediterranean diet had an additive protective effect.
"Overall diet is more important than individual components, with emphasis on moderate--but not excessive--wine consumption, particularly during meals, preference for olive oil as the main added lipid, low consumption of meat, and high consumption of vegetables, fruits, and legumes," author Dr Dimitrios Trichopoulos (Harvard School of Public Health, Boston, MA) told heartwire .
The researchers examined data from healthy individuals in Greece who participated in the European Prospective Investigation into Cancer and Nutrition (EPIC) trial.
Although this study did not examine causes of death, previous studies in this cohort showed that the Mediterranean diet has the greatest effect on cardiac mortality, Trichopoulos said.
The study is published online in BMJ.
A Toast to Long Life
To investigate the relative importance of each of the components of the Mediterranean diet on longevity, the researchers looked at data from the Greek segment of EPIC, from over 23 000 healthy men and women aged 20 to 86 at enrollment.
The researchers calculated a Mediterranean diet score from a diet questionnaire filled in by the participants at study entry.
The diet score was based on nine components of the Mediterranean diet: vegetables, legumes, fruit and nuts, dairy products, cereals, meat and meat products, fish and seafood, monounsaturated-to-saturated lipid ratio, and ethanol consumption.
High consumption of a beneficial food, low consumption of a harmful food (meat or dairy products), and moderate consumption of alcohol were each assigned a value of 1; other levels of consumption were assigned a value of 0, for a score of 0 to 9.
The researchers compared longevity for individuals with scores above or below the median, where the median was about five servings of vegetables and three to four servings of fruits and nuts a day, said Trichopoulos. Moderate intake of alcohol was one to five small glasses of wine (10 g/day to less than 50 g/day) for men and half that for women.
As is typical in the Greek population, many individuals were overweight or obese and many men were smokers. Most were moderately active.
After a mean follow-up of 8.5 years, more deaths occurred in the participants with low vs high Mediterranean-diet scores.
The contribution of each of the diet components to lower mortality were: moderate consumption of alcohol (23.5% of the effect), low consumption of meat (16.6%), high consumption of vegetables (16.2%), high consumption of fruits and nuts (11.2%), high monounsaturated-to-saturated lipid ratio (10.6%), and high consumption of legumes (9.7%).
Eating lots of cereal products and few dairy products contributed to only 5% of the effect, and consumption of fish was associated with a nonsignificant increase in mortality.
Trichopoulos was not surprised that the study found that moderate consumption of alcohol--mostly wine drunk with meals--was such a prominent contributor to longevity. Wine consumed in the Greek diet is comparable to wine consumption that is part of the "French paradox," he noted.
The researchers acknowledge that the long follow-up means that diets could have changed over the study. In addition, the effects of each food might be synergistic.
No Single Miracle Food
Commenting on the study for heartwire , Dr Teresa T Fung (Harvard School of Public Health, Boston, MA), who was not involved with the study, said that she was surprised that moderate consumption of alcohol--which is known to reduce risk of cardiac disease--had such a strong contribution to reduced risk of mortality.
Importantly, this work confirms that it is not one single component of the Mediterranean diet that is driving reduced risk of mortality, she added. "In order to promote longevity, people have to do several things at the same time. They just can't focus on one food--just eat blueberries or take a folic-acid pill. It's a whole lifestyle, whole diet approach for health promotion."
However, the study does not indicate whether each of the components of the Mediterranean diet linked to decreased risk of mortality are also linked to reduced risk of incidence of the diseases that cause the mortality, Fung added.
The authors disclosed having no conflict of interest. The study was supported by the Europe Against Cancer Program of the European Commission, the Greek Ministries of Health and Education, and a grant to the Hellenic Health Foundation by the Stavros Niarchos Foundation.
References
1. Trichopoulou A, Bamia C, Trichopoulos D. Anatomy of health effects of Mediterranean diet: Greek EPIC prospective cohort study. BMJ; 2009: 338:b2337. Abstract
Clinical Context
Adherence to the Mediterranean diet has been shown to be protective for mortality. The effects have been stronger in Mediterranean countries vs western European countries and Sweden, but the relative contribution of each component of the Mediterranean diet to overall survival duration is not well known.
This is a prospective longitudinal cohort study of the Greek segment of the EPIC study that examined the role of biological, dietary, lifestyle, and environmental factors to cancer and other chronic diseases.
Study Highlights
· The EPIC study consisted of participants from 23 research centers in 10 European countries.
· The Greek cohort consisted of 28,572 health men and women aged 20 to 86 years recruited between 1994 and 1997.
· Trained interviewers administered diet and lifestyle questionnaires, and health professionals made anthropometric measurements.
· Dietary intakes during the year before enrollment were assessed, and 150 foods and beverages commonly consumed in Greece were examined with use of standard portion sizes.
· 9 nutritional components of the Mediterranean diet were evaluated: vegetables, legumes, fruits and nuts, dairy products, cereals, meat and meat products, fish and seafood, monounsaturated-to-saturated lipid ratio, and ethanol.
· Conformity to the Mediterranean diet was assessed with a 10-unit scale.
· Ethanol is consumed as part of meals in Greece; median consumption was awarded 1 unit or more, and less than the median consumption was given 0 units.
· Median consumption of alcohol was defined as 10 to 50 g per day for men and 5 to 25 g for women.
· For other components, a score of 1 unit was assigned to consumption of desirable components above the median and 0 for consumption below the median.
· The reverse designation was given for undesirable components such as meat and meat products.
· The total score was summed with a range from 0 to 9 for adherence to the Mediterranean diet, with a higher score representing closer adherence.
· Physical activity was represented as metabolic equivalent of task products representing amount of energy per kilogram of body weight.
· The final sample consisted of 23,349 men and women who were healthy and without cancer, diabetes, or cardiovascular disease at baseline.
· Follow-up occurred for a mean of 8.5 years and a total of 199,726 person-years.
· One third were 45 years and younger at baseline, half had little education, 28% were current smokers, and 30% had moderate ethanol intake.
· A high proportion was overweight or obese (three quarters) and smoked, and the sample had more women than men.
· 1075 deaths occurred in the cohort, of which 652 occurred among 12,694 with Mediterranean diet scores of 0 to 4 and 423 in those with diet scores of 5 or higher.
· The mortality rate was higher in those with lower Mediterranean diet scores.
· There was a significant reduction in total mortality rates per 2-unit increase in Mediterranean diet score (adjusted mortality ratio, 0.864).
· Moderate ethanol consumption contributed the largest portion to this protective effect (23.5%) followed by low consumption of meat and meat products (16.6%) and high vegetable consumption (16.2%).
· High fruit and nut consumption contributed 11.2%, high monounsaturated oil consumption 10.6%, and high legume consumption 9.7%.
· Fish and seafood consumption was associated with a nonsignificant increase in mortality rates, and the authors speculated that this was because of the very low consumption of these items in the Greek population.
· Of 28 two-by-two combinations of components, there was a clear additive effect of 2 or more components in 13 combinations.
· Moderate ethanol consumption, high lipid ratio, and low consumption of meat and meat products were each present 5 times in the 26 possible entries.
· The authors concluded that adherence to the Mediterranean diet was associated with a reduction in mortality rates and the components that contributed the most were moderate ethanol consumption; low intake of meat and meat products; and high intake of vegetables, fruits and nuts, and olive oil and legumes.
Clinical Implications
· Greater adherence to the Mediterranean diet is associated with a decrease in mortality rates.
· The reduction in mortality rates seen with adherence to the Mediterranean diet is attributable to moderate ethanol; low meat and meat product consumption; and high vegetable, fruit, and nut
consumption. (Juli
2009)
