TUESDAY, March 8 (HealthDay News) -- The Mediterranean diet, long known to be heart-healthy, also reduces the risk of metabolic syndrome, a cluster of risk factors that boost the risk of heart disease, stroke and diabetes, according to a new review.

Researchers from Greece and Italy reviewed the results of 50 published studies with a total of more than 500,000 participants as part of a meta-analysis -- a statistical analysis of the findings of similar studies -- on the Mediterranean diet.

Among their findings: the natural foods-based diet is associated with a lower risk of hikes in blood pressure, blood sugar and triglycerides, as well as a reduced risk of a drop in good cholesterol -- all of which are risk factors in metabolic syndrome.

"It is one of the first times in the literature, maybe the first, that someone looks through a meta-analysis at the cardiovascular disease risk factors and not only the hard outcome" of heart disease and other conditions, said Dr. Demosthenes Panagiotakos, an associate professor at Harokopio University of Athens in Greece.

The study is published in the March 15 issue of the Journal of the American College of Cardiology.

The Mediterranean diet is a pattern marked by daily consumption of fruits, vegetables, whole grain cereals, and low-fat dairy products; weekly consumption of fish, poultry, tree nuts, and legumes; high consumption of monounsaturated fatty acids, primarily from olives and olive oils; and a moderate daily consumption of wine or other alcoholic beverages, normally with meals. Red meat intake and processed foods are kept to a minimum.

Metabolic syndrome -- increasingly common in the United States -- occurs if someone has three or more of the following five conditions: blood pressure equal to or higher than 130/85, fasting blood glucose equal to or higher than 100 mg/dL, a waist measuring 35 inches or more in women and 40 inches or more in men, a HDL ("good") cholesterol under 40 in men and under 50 in women, triglycerides equal to or higher than 150 mg/dL.

In the review, Panagiotakos and his team found the Mediterranean diet "is strongly associated with decreased metabolic syndrome risk," declining to pinpoint an exact percentage because the data would not fully support it.

The research team also noted that further study was needed, as a few of the studies reviewed also included interventions such as physical activity and smoking cessation.

The findings come as no surprise, said Dr. Ronald Goldberg, professor of medicine at the Diabetes Research Institute, University of Miami Miller School of Medicine, who reviewed the findings. Since many studies have confirmed the role of the Mediterranean diet on reducing heart disease, he noted, it makes sense that the diet would also reduce the risks that lead up to heart disease.

But since Americans are fond of processed and fast foods, how willing would they be to adopt the diet? "Not particularly," Goldberg acknowledged. But, he added, nutrition experts, recognizing that reluctance, have recently begun efforts to adapt the diet to different cultures -- for example, including many traditional Hispanic foods into a Mediterranean diet adapted for those of Hispanic descent.

By doing so, the diet not only provides the same nutrients as the Mediterranean diet, but the familiar food of one's ethnicity, Goldberg said.

Panagiotakos says even U.S. fast-food-lovers can eat more like Mediterranean's. "Even in fast-food, we can introduce healthy eating, like salads, fruits and vegetables, cereals and legumes, and use good sources of fat. We can replace burgers with all these products -- it is a matter of nutrition education."

More information

To learn more about metabolic syndrome visit the U.S. National Institutes of Health.