People who eat a plant-based Mediterranean diet supplemented with nuts or virgin olive oil can enjoy long-term benefits that potentially include a 30% reduction in the risk of cardiovascular disease, according to a landmark global study.
The study, released Feb. 25 at the sixth International Congress on Vegetarian Nutrition, hosted by Loma Linda (Calif.) University, involved 7,447 individuals (ages 55 to 80) at high risk of cardiovascular disease but with no symptoms.
The results favor two Mediterranean diets (one supplemented with nuts, the other with virgin olive oil) over a low-fat diet for beneficial effects on intermediate outcomes that include body weight, blood pressure, insulin resistance, blood lipids, lipid oxidation and systemicinflammation.
The study, conducted by Spanish researchers and called PREDIMED for PREvención con Dieta MEDiterránea (Prevention with Mediterranean Diet), began in 2003 and was completed in 2011. Participants were followed for an average of 4.8 years. Results also appeared Feb. 25 on the website of the New England Journal of Medicine.
The aim of PREDIMED was to determine whether a plant-based Mediterranean diet, supplemented with either tree nuts such as walnuts, almonds and hazelnuts or virgin olive oil, when compared to a low-fat diet, can help prevent cardiovascular diseases such as cardiovascular death, heart attack and stroke, Miguel Angel Martinez, MD, PhD, of the University of Navarra in Spain, AND a lead investigator of the study, said in a news release.
What we found was that a Mediterranean diet offers a preventive efficacy that was also assessed on secondary variables, including death from all causes, and incidence of diabetes and metabolic syndrome, added Martinez, a physician, epidemiologist and nutrition researcher.
The Mediterranean diet is a pattern of eating similar to the traditional dietary habits of people living in the countries bordering the Mediterranean Sea: fresh fruits and vegetables, seafood, whole grains and nutritious fats, including walnuts and olive oil.
PREDIMED is a parallel group, multi-center, single-blind, randomized clinical trial conducted by 16 research groups in seven communities in Spain. Participants were given dietetic support and quarterly education sessions to ensure compliance. Energy intake was not specifically restricted in any intervention group.
Participants were randomly assigned to one of three groups: low-fat diet (control group), Mediterranean diet supplemented with virgin olive oil (50 milliliters per day), or Mediterranean diet supplemented with 30 grams of mixed nuts per day (15 g walnuts, 7.5 g almonds and 7.5 g hazelnuts).
The study is available at www.nejm.org/doi/full/10.1056/NEJMoa1200303?query=featured_home.