According to a Spanish study eating a Mediterranean diet rich in fruit, vegetables and fish along with a handful of mixed nuts daily could help reduce risk factors for heart disease. Also known as metabolic syndrome, it includes problems like abdominal obesity, high cholesterol, high blood pressure and high glucose levels all of which are risk factors for cardiovascular disease. Previously researchers believed that a typical Mediterranean diet which includes lots of cereals, vegetables, fruits and olive oil, moderate consumption of fish and alcohol, and low intake of dairy, meats and sweets helped reduce the risk of metabolic syndrome. In the recent study researchers found that by adding nuts to the diet the results were better than boosting olive oil in the Mediterranean diet or a low fat diet.

The study was on 1224 people in the age group of 55 to 80 who were at high risk for cardiovascular disease. They were randomly divided into three groups in which the control group received a low fat diet, and the other two groups were advised on the Mediterranean diet. Out of these two one Mediterranean diet groups was given one liter per week of virgin olive oil while the other group was given 30 grams of mixed nuts per day.

The researchers found that at the start of the study 61.4 % of the participants met the criteria for metabolic syndrome which after a year decreased by 13.7 % in the mixed nut group, 6.7 % in the olive oil group and by 2 % in the control group. No weight change was noted in any of the groups over the one year period of the study but there was a significant decrease in the waist circumference, high triglycerides or high blood pressure of those in the Mediterranean diet as compared to the control group.

Dr. Jordi Salas-Salvado, of the University of Rovira i Virgili, and colleagues said, "Traditionally, dietary patterns recommended for health have been low-fat, high-carbohydrate diets, which generally are not palatable. The results of the present study show that a non-energy-restricted traditional Mediterranean diet enriched with nuts, which is high in fat, high in unsaturated fat and palatable, is a useful tool in managing the metabolic syndrome."

Dr. JoAnn Manson, chief of preventive medicine at Harvard's Brigham and Women's Hospital who wasn't involved in the study, cautioned that adding nuts to a Western diet with too many calories and junk food could lead to weight gain and more health risks. "But using nuts to replace a snack of chips or crackers is a very favorable change to make in your diet," Manson said.

"Nuts could have an effect on metabolic syndrome by multiple mechanisms," Salas-Salvado said. Nuts are rich in anti-inflammatory substances, such as fiber, and antioxidants, such as vitamin E. They are high in unsaturated fat, a healthier fat known to lower blood triglycerides and increase good cholesterol.

The study was funded by the Spanish Ministry of Health and the government of Valencia, Spain and published Dec. 8 in the journal Archives of Internal Medicine.