Mediterranean Diet May Fight Heart and Diabetes Risks

Foods common in the Mediterranean diet may fight metabolic syndrome

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Good food is essential to good health. By following the Mediterranean diet, patients may be able to reduce obesity, high blood sugar and other factors that promote heart disease and type 2 diabetes, a new study found.

The American Heart Association estimates that more than 1 in 3 US adults have metabolic syndrome. This cluster of conditions can have a serious impact on heart health.

Researchers recently found that a Mediterranean-based meal plan with olive oil or nuts may reverse metabolic syndrome. This, in turn, may lower the risk of diabetes and heart disease.

"Metabolic syndrome is usually defined as increased abdominal girth (weight), low HDL (good cholesterol), high glucose/diabetes and high blood pressure," explained Rohit Parmar, MD, FACC, a cardiologist at Baylor Heart and Vascular Hospital and Assistant Professor of Medicine at the Texas A&M College of Medicine.

"Research shows that a Mediterranean diet with olive oil reduces obesity and blood sugar. These, in turn, could help curb the propensity for heart disease," said Dr. Parmar, who was not involved in this study.

The new study was written by Jordi Salas-Salvadó, MD, PhD, of the Universitat Rovira i Virgili in Spain, and colleagues.

A total of 7,447 patients were divided into three groups. One followed a Mediterranean diet supplemented with olive oil. One followed the same diet with the addition of nuts. The third group — the control group — followed a low-fat diet.

After an average follow-up of almost five years, the study authors observed that the olive oil group significantly lowered their obesity and high blood sugar. The nut group had a significant drop in obesity.

At the start of the research, 3,707 patients had metabolic syndrome. At follow-up, 958 (about 28 percent) among all three groups no longer had the condition.

Metabolic syndrome is a cluster of factors that can lead to heart disease and type 2 diabetes. They include high blood pressure, high blood sugar, excess body fat around the waist and abnormal cholesterol levels.

“Compared with the control group, participants on either Mediterranean diet were more likely to undergo reversion,” the authors wrote.

A total of 2,543 patients were in the olive oil group. The nut group had 2,454. The remainder were in the control group.

The study authors noted, however, that the Mediterranean diet did not seem to affect the number of new cases of metabolic syndrome. They reviewed data on 2,094 people who did not have the condition at the start of the study. They found no differences in incidence of metabolic syndrome among the groups.

Patients in this study ranged in age from 55 to 80. They either had type 2 diabetes or at least three heart disease risk factors. These factors included high blood pressure, high low-density lipoprotein (or “bad”) cholesterol levels and low high-density lipoprotein (or “good”) cholesterol levels. Other risks factors were being overweight or obese, a history of smoking and a family history of coronary artery disease.

A person with type 2 diabetes produces the hormone insulin but does not use it effectively. Insulin normally helps cells use blood sugar (glucose). With type 1 diabetes, the body does not produce insulin.

Those assigned to a Mediterranean diet were given information on foods, seasonal shopping lists, meal plans and recipes. In the control, low-fat diet group, patients were told to reduce their intake of all types of fat.

“[Mediterranean] diets may be useful in reducing central obesity and [high blood sugar] in patients with high risk of cardiovascular disease,” the authors wrote.

"I would recommend the Mediterranean diet to reduce the likelihood of worsening heart disease," Dr. Parmar said. "I believe that the diet can have multiple positive effects including weight loss, better glucose control and potentially better blood pressure control as well. This, in turn, could translate to reduction in heart disease."

The study was published Oct. 14 in CMAJ.

The authors disclosed several conflicts of interest, such as support received from the Research Foundation on Wine and Nutrition, Mediterranean Diet Foundation, International Nut Council, International Nut and Dried Fruit Council and the California Walnut Commission.

Review Date: 
October 14, 2014
Last Updated:
March 16, 2015