March 8, 2011 -- The Mediterranean diet is known to help prevent heart disease. Now new research extends these benefits to metabolic syndrome, a cluster of risk factors that includes high blood pressure, abdominal obesity, high cholesterol levels, and insulin resistance that increase risk for diabetes and heart disease.
Researchers analyzed the results of 50 studies comprising more than 500,000 people to show that the Mediterranean diet can reduce the risk of metabolic syndrome. The new findings appear in Journal of The American College of Cardiology.
A Mediterranean-style diet is rich in heart-healthy fats (such as olive oil), colorful fruits and vegetables, whole grains, low-fat dairy, and moderate amounts of alcohol. This diet also incorporates leaner proteins like poultry and fish instead of red meat. This diet has numerous sources of antioxidants and anti-inflammatory compounds, which may account for its positive health effects.
“Encouraging adherence to the Mediterranean diet might be a solution to the problem [of metabolic syndrome] because the foods comprising this dietary pattern -- apart from its various health benefits -- are tasty and it is easy to follow in the long term,” conclude researchers, who were led by Demosthenes Panagiotakos, PhD, associate professor at Harokopio University of Athens in Greece. “These results are of considerable public health importance because this dietary pattern can be easily adopted by all population groups and various cultures and cost-effectively serve for the primary and secondary prevention of the [metabolic syndrome] and its individual components.”
In addition to effects on markers of metabolic syndrome, the study revealed that the Mediterranean diet also boosts levels of high-density lipoprotein or "good” cholesterol. Physical activity enhances the positive benefits of the diet, the new study showed.
Mediterranean Diet Helps Prevent and Treat Metabolic Syndrome
“Does the Mediterranean diet prevent heart disease and make you live longer? The answers are yes and yes,” says Marc Gillinov, MD, a staff cardiac surgeon at The Cleveland Clinic Heart and Vascular Institute in Ohio. The new study “includes more patients than any previous study, and it addresses specifically metabolic syndrome, which previous studies haven’t looked at.”
“It broadens the message about the Mediterranean diet,” he says. “If someone says ‘I want to avoid heart disease or I have heart disease, what diet should I choose?’ I would say the Mediterranean diet. And now, with this study, if someone has some abdominal obesity, a little high blood pressure, and is developing diabetes and asks ‘what diet should I choose?’ based on this study, I can say the Mediterranean diet,” Gillinov says.
“This is an excellent study in terms of depth -- to combine 50 studies for a total of over half a million participants is tremendous and gives excellent ... information,” says Jessica Bartfield, MD, an internist at Gottlieb Memorial Hospital, part of Loyola University Health System in Maywood, Ill.
“The conclusion that consumption of a Mediterranean diet lowers the prevalence and progression of the metabolic syndrome helps better support data from trials that already suggest this,” she says in an email. “We know omega-3 fatty acids, which are found in olive oil and other monounsaturated fats, are anti-inflammatory.”
Inflammation is a known risk factor for heart disease and stroke, she says. “It makes sense that a Mediterranean diet can tame this inflammation and provide a protective benefit,” she says.
That said, the new study does have its share of limitations. “The studies varied greatly in terms of length with some as short as four weeks, some as long as four years, and only a few were conducted in the U.S. population where the food culture varies tremendously by region,” she says.
But “in the never-ending quest for the ‘perfect diet’ -- low-fat, high-protein, low-carb, no-sugar ... I would say that the Mediterranean diet comes pretty close,” she says.
Simple Changes, Big Benefits
Suzanne Steinbaum, MD, director of women and heart disease at Lenox Hill Hospital in New York City, is a big advocate of the Mediterranean lifestyle. “This is the only thing I recommend for people,” she says. “This is a lifestyle, not a diet."
Little changes go a long, long way, she says.
“Fats don’t have to be creamy,” she says. “Cook with a tomato-based sauce with olive oil, and get rid of fried foods and grill with olive oil instead,” she says. “Choose different grains instead of white rice, and eat more fish and nuts and legumes and vegetables."
Being more active is also a part of this lifestyle, she says.