Mediterranean Diet May Be Effective in Reducing Metabolic Syndrome and Associated Symptoms

CHICAGO, IL -- September 22, 2004 -- In a study in the September 22/29 issue
of JAMA, Katherine Esposito, M.D., of the Second University of Naples, Italy,
and colleagues demonstrated that a Mediterranean-style diet had beneficial
effects on endothelial (a layer of flat cells lining the closed internal spaces of
the body, including the blood vessels) function and in reducing vascular
inflammatory markers in patients with the metabolic syndrome.

According to background information in the article, the metabolic syndrome
consists of several factors that increase the risk of cardiovascular disease
and type 2 diabetes. Recent estimates indicate that the metabolic syndrome
is highly prevalent in the United States, with an estimated 24 percent of the
adult population affected. Its clinical identification is based on measures of
abdominal obesity, atherogenic dyslipidemia (the formation of high levels of
lipid deposits in the arteries), elevated blood pressure, and glucose
intolerance. The metabolic syndrome has been identified as a target for
dietary therapies to reduce risk of cardiovascular disease; however, the role
of diet as contributing to the metabolic syndrome is poorly understood.

The randomized trial was conducted from June 2001 to January 2004 at a
university hospital in Italy among 180 patients (99 men and 81 women) with
the metabolic syndrome. Patients in the intervention group (n=90) were
instructed to follow a Mediterranean-style diet and received detailed advice
about how to increase daily consumption of whole grains, fruits, vegetables,
nuts, and olive oil; patients in the control group (n=90) followed a prudent diet
(carbohydrates, 50 percent-60 percent; proteins, 15 percent-20 percent; total
fat, less than 30 percent).

The researchers found that after 2 years, patients in the Mediterranean diet
intervention group had significant decreases in body weight, blood pressure,
levels of glucose, insulin, total cholesterol, and triglycerides and a significant
increase in levels of high-density lipoprotein cholesterol, all of which were
greater than those recorded in the control group. Serum concentrations of
interleukins 6 (IL-6), 7 (IL-7), and 18 (IL-18) and high-sensitivity C-reactive
protein (hs-CRP) were significantly reduced in patients in the intervention
group compared with those in the control group. Endothelial function score
improved in the intervention group but remained stable in the control group.
Forty patients consuming the intervention diet still had features of the
metabolic syndrome, compared with 78 patients consuming the control diet.
Participants who followed the intervention diet showed a reduction in the
number of the components of the syndrome such that the overall prevalence
of the metabolic syndrome was reduced by approximately one half.

"The results of this study represent the first demonstration, to our knowledge,
that a Mediterranean-style diet rich in whole grains, fruits, vegetables,
legumes, walnuts, and olive oil might be effective in reducing both the
prevalence of the metabolic syndrome and its associated cardiovascular
risk," the authors conclude.

This study was funded by the Second University of Naples.


SOURCE: JAMA and Archives Journals Website