Mediterranean diet cuts heart disease risk - update

Eating a Mediterranean diet can reduce the risk of heart disease, researchers have confirmed in the November 1 issue of American Journal of Clinical Nutrition. 

Previous studies of people that follow a Mediterranean diet have already shown that this type of diet is associated with a reduced risk of heart disease as well as some forms of cancer. 

In the current study, Dr. Denis Lairon of the Faculty of Medicine Timone in Marseille, France and colleagues found that eating a Mediterranean diet for three months can lower the cardiovascular risk by 15 percent. 

A typical Mediterranean diet contains a large amount of whole grain breads and cereals, fruit, beans, potatoes, seeds. Olive oil is the main source of fat. The main meat is poultry and fish with little red meat. Wine is used in low or moderate amounts along with meals. 

In the study, 212 men and women at moderate risk were assigned a Mediterranean diet or a standard low-fat diet for three months. 

The Mediterranean diet group was instructed to have fish four times a week and red meat once a week. Researchers recommended two glasses of red wine daily for men and one drink a day for women. 

The control group ate poultry, but no beef, pork and other mammal meats; ate fish twice or three times a week, but did not use animal fat-rich products; and ate fruit and vegetables, low-fat dairy products, and vegetable oils. 

Overall, both groups had a lower calorie intake and consumed more proteins and carbohydrates, but less total fat and saturated fat. As a result, both groups showed a small, yet significant decrease in body mass index. 

The total cholesterol was measured before and after meals. Among those using the Mediterranean diet, the total cholesterol dropped by 7.5 percent compared with 4.5 percent in the low-fat group. This reduction can be translated, according to the authors, into a 15 percent cut in the cardiovascular disease risk in the Mediterranean diet group and 9 percent in the low-fat diet group. 

The researchers conclude that eating good diets can significantly reduce cardiovascular disease risk. 

Previous studies indicate that Mediterranean diet benefits may be attributed in part to its unique profile of fatty acids such as monounsaturated fatty acids in olive oil and omega-3 fatty acids in fish, and naturally occurring antioxidants such as phenols. 

A recent study, conducted by Dr. Francisco Perez Jimenez of the Hospital Universitario Reina Sofia in Cordoba and colleagues showed phenols found in the olive oil commonly used in a Mediterranean diet are responsible for the heart healthy effects although other beneficial factors were not be excluded. 

The study involved 21 people with high cholesterol. The participants were given a meal with either untreated olive oil or phenolic acid-stripped olive oil. They measured the functionality of the participants' blood vessels, that is, ability of the blood vessels to respond to rapid changes in blood flow after a relatively high-fat meal with either type of olive oil. 

The blood vessel response and function was improved in the group using the high phenol olive oil meal while no improvement was observed in the control group. The finding was published in the November issue of Journal of the American College of Cardiology. 

Other studies have shown that a supplement of omega-3 fatty acids, which are commonly found in fish, reduces heart disease events and markers of heart disease risk in patients with heart disease or risk factors for heart disease, according to clinicaltrials.gov. 
http://www.clinicaltrials.gov/ct/gui/show/NCT00166088

Some other studies of patients with either known heart disease or risk factors for heart disease have shown a reduction of heart disease events, such as heart attacks, as well as markers of heart disease risk when patients followed a Mediterranean diet. 

In sharp contrast to the Mediterranean diet, a typical American diet has high intake of fats such as saturated fats, cholesterol, and trans fat and low intake of fish and omega-3 fatty acids. Such a diet is known to raise high blood levels of cholesterol, harden the arteries, and increase the risk of heart disease. 

Due to a variety of its benefits, the Mediterranean diet has been intriguing the academic community. Emory University has been recruiting patients for a clinical trial "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," according to Clinicaltrials.gov. 

While olive oil is an indispensable ingredient in the Mediterranean diet, Consumers, who are interested in reducing the risk of heart disease, should remember that the maximum heart healthy benefit comes from virgin or extra virgin olive oil.