Effect of a Mediterranean Diet and Omega-3 Fatty Acids on Oxidative Stress and Endothelial Progenitor Cells (EPC's)

Problem of Interest:

A typical American diet that is high in an intake of fats (especially saturated fats and
cholesterol) is known to lead to high blood levels of cholesterol, hardening of the
arteries, and increases the risk of heart disease. The American Heart Association
recommendations to follow a diet that is low in the amount of fat, and specifically
cholesterol, that is eaten can improve blood levels of cholesterol but can lead to a high
intake of sugars (especially processed sugars) that can lead to obesity and continued heart
problems.

Studies of people who eat a diet that is typical of the Mediterranean region have shown that
this type of diet leads to reductions in heart disease as well as forms of cancer. A
typical Mediterranean diet has a large amount of fruit, vegetables, whole grain breads and
cereals, beans, potatoes and seeds. Olive oil is the main source of fat and there is a
daily use of dairy products (such as cheese and yogurt) in low to moderate amounts. The
main meats are fish or poultry with rare red meat. Desserts are usually fruits with rare
sweets. Wine is also used in low to moderate amounts with meals.

No isolated aspect of the diet explains all of its benefits, but it is believed that the
ingredient of the diet that most helps to reduce the risk of heart disease is the high
amount of omega-3 fatty acids. Omega-3 fatty acids are found in fatty fish as well as in
nuts and certain oils. Several studies of patients with either known heart disease or risk
factors for heart disease have shown a reduction in heart disease events, such as heart
attacks, as well as markers of heart disease risk when patients followed a Mediterranean
diet. Other studies have shown that giving a supplement that contains omega-3 fatty acids to
patients with heart disease or risk factors for heart disease also reduces heart disease
events and markers of heart disease risk.

In this current study we, the investigators at Emory University, plan to compare the effects
of following a Mediterranean diet versus continuing to follow an American type diet and
supplementing parts of the Mediterranean diet, including omega-3 fatty acids, on markers of
heart disease risk. A third group will continue to follow their usual diet without
supplements to serve as a control.

How Problem Will be Studied:

In this initial study we will compare three groups. One group will receive one month of
prepared meals that will follow a Mediterranean diet. This group will also receive
extensive counseling and education on how to maintain a Mediterranean diet. During the
second month of the study this group will be encouraged to continue following a
Mediterranean diet by themselves with assistance from a nutritionist. The second group will
be asked to continue on their current diet and receive supplements that are important parts
of the Mediterranean diet. These supplements will include an omega-3 fatty acid capsule,
walnuts and grape juice. A third group will be asked to continue their current diet and
level of activity without supplements to serve as a control. We will follow the effects on
markers of heart disease risk. We will also determine if patients are able to continue
following a Mediterranean diet on their own or whether simply taking supplements is easier.

Advancement in Scientific Knowledge:

This study will advance scientific knowledge by comparing the effects of following a
Mediterranean diet versus simply taking supplements of the believed to be important aspects
of the Mediterranean diet. We will also be able to determine if it is easier to follow a
Mediterranean diet or take supplements for patients who are currently ingesting a typical
American diet.

Standard of Care:

Currently the recommended diet for all Americans is a Step 1 American Heart Association diet
that is low in fat and specifically low in saturated fats and cholesterol. As stated above,
despite these recommendations, there is a growing problem of obesity in the United States
and there is evidence to suggest that a Mediterranean diet may be better.