(NaturalNews) A large, multicenter clinical trial has provided some of the strongest evidence yet that a Mediterranean diet plus added olive oil or nuts protects all parts of the cardiovascular system, helping to prevent heart attack, stroke and peripheral artery disease. The most recent findings were published in the Journal of the American Medical Association.
The Mediterranean diet emphasizes high consumption of beans, whole grains, seeds and nuts, and olive oil; yogurt and cheese as the main dairy sources; moderate fish and poultry consumption; low red meat consumption; and low to moderate consumption of red wine.
The trial was conducted between October 2003 and December 2010 on 7,477 participants of average age 67 (58 percent women). All of the participants were free of cardiovascular disease or peripheral artery disease at the study's start, but all were considered at high risk of cardiovascular disease (either because they were diabetic or because they had at least three other cardiovascular risk factors).
Participants were randomly assigned to follow one of three diets: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with nuts or a control consisting simply of counseling on how to follow a low-fat diet. Four times a year, a dietitian met with the participants to review their eating habits and help them set dietary goals for the next quarter. At these meetings, participants in the Mediterranean diet groups were given free olive oil or nuts, as well as shopping lists, menus and recipes.
Diet halves risk
The study's most recent findings concern peripheral artery disease, which occurs when plaque builds up in the arteries carrying blood to the legs and feet. Symptoms include fatigue and leg pain, particularly while walking.
The researchers found that participants consuming a Mediterranean diet plus nuts were 50 percent less likely to develop peripheral artery disease than participants in the control group. Those on the Mediterranean diet plus olive oil were 64 percent less likely.
"To our knowledge, this is the first randomized primary prevention trial to suggest an association between a dietary intervention and [reduction in] PAD," the researchers wrote. "These results are consistent with previous observational studies."
In results from the same trial previously published in The New England Journal of Medicine, the researchers found that participants on both Mediterranean diets were also 28 to 30 percent less likely to develop cardiovascular disease than participants in the control group.
"Now we have this very strong reduction in the risk of peripheral artery disease," researcher Miguel Martinez-Gonzalez of the University of Navarra in Pamplona, Spain, said. "This is very reassuring."
"From a biological, mechanistic point of view, the underlying disease process for peripheral artery disease is exactly the same as for stroke or [heart attack]," Martinez-Gonzalez said. "It is atherosclerosis, or disease of the arteries."
It's easy to switch
The Mediterranean diet has previously been linked to a number of health benefits including a reduced risk of type 2 diabetes and cognitive decline, and overall better health and a longer lifespan.
Martinez-Gonzalez suggested that people wanting to switch over to a Mediterranean diet start with small, achievable changes, such as drinking a glass of red wine each night, increasing their consumption of vegetables cooked with olive oil, substituting fish or poultry for red meat or substituting fruits for sweets as desserts.
Nutrition researcher Teresa Fung of Simmons College, who was not involved in the study, had another suggestion: snacking on a handful of nuts, rather than on cookies or chips.
"All of these steps are making, at the end of the day, a big difference," Martinez-Gonzalez said.