Olive Oil and Nuts Fight Off Diabetes

Diabetes risk may decrease with unrestricted Mediterranean diet supplemented by olive oil and nuts

/ Author:  / Reviewed by: Robert Carlson, M.D Beth Bolt, RPh

(RxWiki News) To ward off diabetes, people generally avoid all-you-can eat menus. Counting calories, however, may not be such a problem for those who follow a Mediterranean diet. Which inclues olive oil and nuts.

For years now, health advocacy groups such as the American Diabetes Association and the American Heart Association have been touting the health benefits of “The Mediterranean Diet,” which is rich in vegetables, fruits, grains, beans and fish.

"So the real end result is if you give people initially on a high fat diet free olive and free nuts so that their polyphenol levels increase and their inflammation levels decrease, then they will probably have less heart attacks or diabetes compared to those on a high-fat die without extra free polyphenols," Dr. Sears said.

While consuming too many calories typically leads to weight gain and increases diabetes risk, scientists have recently found that diabetes risk may be lowered for those who followed a Mediterranean diet without any calorie restrictions.

"Eat healthy to lower diabetes risk."

Jordi Salas-Salvadó, MD, a professor of nutrition at Rovira i Virgili University and the head of the Department of Nutrition at the Hospital de Sant Joan de Reus in Spain, and his colleagues followed 3,541 men and women who were at a high risk of heart disease but had no diabetes at the beginning of the study.

Ranging in age from 55 to 80, these subjects had at least three cardiovascular risk factors, such as smoking, being overweight and high cholesterol.

The scientists set out to find how olive oil and nuts, which are rich in heart-healthy unsaturated fats, might affect the onset of diabetes, regardless of how many calories participants consumed.

People with diabetes are at high risk of heart disease, so the American Diabetes Association recommends eating more healthy unsaturated fat and less saturated fat, which can be found in dairy products (such as butter and ice cream), red meats, lard and coconut oil.

Participants in this study were randomly assigned to follow one of three diets — 1,154 stuck to a Mediterranean diet including just over three tablespoons of extra-virgin olive oil daily; 1,147 followed a Mediterranean diet plus about two tablespoons of mixed nuts daily; and 1,240 were assigned to a control group.

The control group received recommendations to reduce intake of all types of fat (from both animal and vegetable sources), but they were not assigned to follow a Mediterranean diet.

Those following a Mediterranean eating plan had dietary training sessions, seasonal shopping lists, meal plans and recipes.

Dietitians advised participants on use of extra-virgin olive oil for cooking and dressing; weekly nut consumption; increased intake of vegetables, fruits, beans and fish; recommended eating of white meat instead of red or processed meat; avoiding butter, fast food, sweets, pastries or sugar-sweetened beverages; and enhancing dishes with a “sofrito” sauce that uses tomato, garlic, onion and spices simmered in olive oil.

All participants were encouraged to drink fewer alcoholic beverages other than wine.

Although diet and exercise may possibly cut diabetes risk further, participants were not asked to decrease their calorie consumption or increase their exercise. After about four years, the researchers observed that 273 individuals had developed diabetes — 80 (6.9 percent) from the olive oil group, 92 (7.4 percent) from the nut group and 101 (8.8 percent) from the control group.

Based on these results, the authors concluded, “A Mediterranean diet without calorie restrictions that is supplemented with extra-virgin olive oil or nuts may reduce the risk for type 2 diabetes.”

"The diabetes study was flawed from the start. The groups who got free extra-virgin olive oil and free nuts were also essentially getting free polyphenols. The group supposedly on a low fat diet never changed their diet from the initial high fat diet," explained Dr. Barry Sears, President of the non-profit Inflammation Research Foundation in Marblehead, MA and creator of The Zone Diet.

This study was published in the January 7 issue of the Annals of Internal Medicine. Grant support was provided by the official funding agency for biomedical research of the Spanish government, Instituto de Salud Carlos III.

Review Date: 
January 7, 2014
Last Updated:
March 16, 2015