The
New England Journal of Medicine recently published an
article by University of Barcelona professor of medicine Dr. Ramon Estruch and colleagues claiming that a Mediterranean diet can help prevent heart attacks, strokes, and death in high risk people. Such a diet “is characterized by a high intake of olive
oil, fruit, nuts, vegetables, and cereals; a moderate intake of fish and poultry; a low intake of dairy products, red meat, processed meats, and sweets; and wine in moderation, consumed with meals,” defines the article.
The study’s methodology involved assigning 7,447 men and women between the ages of 55 and 80 to one of three dietary intervention groups. The participants were free of cardiovascular problems at the time of enrolling in the trial, but were considered high
risk due type 2 diabetes, or to a combination of factors such as obesity, smoking, hypertension, and family history of heart disease. Of the
dietary intervention groups, one was asked to follow recommendations for a low-fat diet. The other two were asked to follow recommendations for a Mediterranean diet and provided either a liter of free extra-virgin olive oil per week or 30 g of mixed nuts
per day. For all groups, no calorie restrictions or physical activities were specified. The rates of heart attack, stroke, and death were measured in each group over about 5 years, at the end of which researchers found about a 30% percent relative risk reduction
for the Mediterranean dieters versus the low-fat control.
According to Rachel Johnson, a professor of nutrition at the University of Vermont and a spokeswoman for the American Heart Association, the study is impressive for its salient endpoints. “They did not look at risk factors like cholesterol or hypertension
or weight. They looked at heart attacks and strokes and death. At the end of the day, that is what really matters,” she says in this
New York Times article.
Nevertheless, there are some methodological concerns with the study, which Larry Husten outlines in this
Forbes
article. The low fat control group wasn’t given the same support as the Mediterranean diet groups. Also, according to Dean Ornish, president of the Preventive Medicine Research Institute and a well-known advocate of the low-fat diet, the control group
was not following a low fat diet at all. “In the ‘low-fat’ group, total fat consumption decreased insignificantly, from 39 percent to 37 percent,” says Ornish in this
Huffington Postarticle. “This doesn’t even come close to the American Heart Association guidelines of a low-fat diet (
Husten points out that, since the Mediterranean dieters were being given free, healthy provisions, the most productive lesson to take from the study might be for public health policy. “Make healthy foods available to people,” says Husten. “If people substitute
walnuts or olive oil for a candy bar or french fries then they will benefit.”
To learn more about how scientists study the effects of diets, check out this podcast,
A Thought for Food: How Do We Know What We Know? And, since wine is a component of the Mediterranean diet, try
Getting Behind the Resveratrol Hype, which looks at what science does—and does not—recommend about this compound found in red wine and chocolate.
Plant geneticist Paul Gepts, economic journalist Fred Kaufman, ethicist Paul Root Wolpe, and intellectual property lawyer Rochelle Dreyfuss discuss hot-button issues in food security, including GMOs, biotech, trade, and patents.
