Incorporating a handful of walnuts into a healthy diet may help people with type 2 diabetes (search) improve their cholesterol levels and reduce their risk of heart disease, a new study suggests.

Researchers found including walnuts (search) as part of a balanced, low-fat diet helped people with diabetes increase their “good” HDL cholesterol levels while lowering their “bad” LDL cholesterol levels.

But don’t reach for the nut bowl just yet. Experts say merely adding walnuts to an already unhealthy diet won’t necessarily undo the damage. Instead, they say it’s important to substitute walnuts for other sources of fat in the diet in order to achieve the best results.

Walnuts contain an omega-3 fatty acid (search) called alpha-linolenic acid (search) or ALA, which is similar to the omega-3 fatty acids found in fatty fish, such as salmon. Previous studies have shown that alpha-linolenic acid has a number of heart-healthy effects, including improving cholesterol levels.

Researchers say this is one of the first studies to look at the effects of the fatty acids found in walnuts in people with type 2 diabetes.

Walnuts May Aid in Diabetes Management

In the study, which appears in the December issue of Diabetes Care, researchers looked at the effects of three different diets on cholesterol levels in older adults with type 2 diabetes.

Nearly 60 men and women were divided into three groups that followed three different diet plans: a low-fat diet, a modified-fat diet, or a modified-fat diet that included eight to 10 walnuts per day (30 grams). All of the diets were based on eating a variety of whole foods, such as cereals and breads, fruits and vegetables, lean meat, fish, and low-fat dairy products with no more than 30 percent of total calories from fat.

After six months of the diet, the results showed that the people who ate the modified-fat diet including walnuts experienced a bigger increase in “good” HDL cholesterol levels than those in the other two diets. People who ate walnuts as part of a balanced diet also experienced an average 10 percent reduction in “bad” LDL cholesterol levels.

Researchers say the study suggests that incorporating walnuts into a healthy diet may be an easy way for people with type 2 diabetes to get the right kinds of fats and fatty acids into their diet.

“Walnuts are an easy and convenient way of getting polyunsaturated omega-3 fatty acids into the diet. And they're particularly important for people with diabetes because they're a simple snack food, which is an integral component of managing the diet in diabetes," says researcher Linda Tapsell, PhD, of the University of Wollongong in Australia, in a news release.

Although the walnut diet appeared to help improve cholesterol levels in people with type 2 diabetes, no significant differences were found between the groups in terms of body weight or body fat.

Funding for the study was provided by the California Walnut Commission.

By Jennifer Warner, reviewed by Brunilda Nazario, MD

SOURCES: Tapsell, L. Diabetes Care, December 2004; vol 27: pp 2777-2783. News release, University of Wollongong.