2 Recent Studies Support the Mediterranean Diet

olivesMore information keeps coming out about the benefits of eating in the Mediterranean style, broadly defined as rich in fresh fruits and vegetables, healthy fats, avoiding red meat and processed foods, drinking wine in moderation, and eating with friends and family.  Given the many variables that go into a cuisine, it is hard to tease out what exactly accounts for this risk reduction, and it might just be more general principles like small portions, daily exercise, and an emphasis on freshness, balance, and pleasure in food.

Studies demonstrating the health benefits, lower cancer risk, and lower heart disease risk of those following the Mediterranean diet are becoming more numerous, with a few of the major ones summarized on Wikipedia and in this meta-analysis in the BMJ.

The first of the two new studies I’m going to highlight found that the Mediterranean diet can reduce the need for medications among people newly diagnosed with diabetes. From a summary of the study published in the Annals of Internal Medicine:

Researchers in Naples, Italy, compared a low-carbohydrate Mediterranean-style diet with a low-fat American Heart Association (AHA) diet in a 4-year randomized trial that involved 215 adults with newly diagnosed type 2 diabetes (not yet on medication), body-mass index >25 kg/m2, and glycosylated hemoglobin (HbA1c) levels <11%. Both diets were rich in whole grains and provided 1500 kcal daily for women and 1800 kcal daily for men. The Mediterranean diet was rich in vegetables and low in red meat (emphasis on poultry and fish), had no less than 30% of calories from fat (30–50 g olive oil daily), and allowed no more than 50% of calories from complex carbohydrates. The AHA diet was restricted in sweets and high-fat snacks and allowed no more than 30% of calories from fat and no more than 10% of calories from saturated fat.

Fewer Mediterranean diet than AHA diet participants required medication to achieve HbA1c levels <7% at 18 months (12% vs. 24%) and at the end of the study (44% vs. 70%). Mediterranean diet participants also had more weight reduction from baseline (by 2 kg) and had greater improvements in levels of HbA1c, fasting plasma glucose, HDL cholesterol, and triglycerides.

The notions that “all fat” is bad for you, and that a low fat diet will necessarily help you live longer have been debunked by recent studies. Instead, an emphasis on healthy fats seems more evidence-based. Olive oil, canola oil, nuts like walnuts and almonds, fatty fish, avocadoes, and flaxseed are examples of foods with “good” fat profiles.

The second study, just published last month, found a lower incidence of depression among people who most closely followed the tenets of the Mediterranean diet.  From Journal Watch‘s summary of the Archives of General Psychiatry article:

Some 10,000 young adults in Spain completed food-frequency questionnaires to assess how well they followed a Mediterranean dietary pattern (i.e., high in fruits, vegetables, fish, nuts, cereal, and legumes; low in meat and whole-fat dairy; moderate alcohol intake; and high ratio of monounsaturated-to-saturated fatty acids).

After a median 4 years’ follow-up, people in the top three quintiles of diet adherence had lower hazard ratios for incident self-reported depression than those in the lowest quintile. High consumption of fruits and nuts, legumes, and fish were each separately associated with lower depression risk.

The authors speculate that the observed effect may be explained by the diet’s beneficial impact on endothelial function, which may, in turn, improve production of brain-derived neurotrophic factor — reported to be reduced in depression.

So how does one incorporate the Mediterranean diet into one’s lifestyle?  A few consistent patterns emerge.  Most characterizations include:

– fresh, healthy, non-processed food
– small portions
– healthy fats
– high in omega 3 fatty acids
– olive oil as the main cooking oil and component of dressings
– more vegetables
– less meat, especially red meat
– fish or shellfish at least twice per week
– wine in moderation
– whole grains, beans, and legumes
– fruit for dessert

I realize these kinds of studies are very difficult to analyze, since so many factors are in play in a cuisine or lifestyle. But incorporating these general principles does not seem that burdensome, especially when compared to other diets that micromanage specific nutrients and treat all fat as sinful, while elevating the chaste misery of the rice cake to dogmatic perfection.

Now if we could all just get private villas on the Mediterranean Sea, surrounded by fresh foods, wine, and family, there would be a lot fewer heart attacks I’m certain.