Good oil in walnuts helps diabetes patients

Dec 4 2004

People developing Type 2 Diabetes know they need more than an apple a day to keep the doctor away. But a handful of walnuts might help.

Walnuts are rich in polyunsaturated fats, Omega oils and vitamins.

Researchers at the University of Wollongong's Smart Foods Centre today released the results of a study that shows how to harness the nutritional value of walnuts, especially the “good” oils, to help people manage their diet better in the early stages of Type 2 Diabetes Mellitus.

The research showed that including walnuts in the diet improves the relative amounts of “good” cholesterol in this group of patients.

The research findings are in the December issue of the international journal Diabetes Care, published in the United States.

That's good news for Australia's 1.2 million people suffering from Diabetes, and the further two million estimated to have pre-Diabetes and be at risk of developing the disease.

National Centre of Excellence for Functional Foods and former Smart Foods Centre Director Professor Linda Tapsell said the research had demonstrated how a diet including 8-10 walnuts a day delivered the right kinds of fats and fatty acids that might help the body address one of the problems associated with early stage Type 2 Diabetes - insulin resistance - which hinders the absorption of glucose from the bloodstream into human cells.

“We understood the relationship between insulin resistance and fatty acids, and when we looked at the composition of walnuts we thought that they could be useful in delivering the right kinds of fatty acids. We knew walnuts contained substantial amounts of these fats, so our challenge was to prove that the theoretical benefits were real,” Professor Tapsell said.

The team of dietitians from the Smart Foods Centre and the Illawarra Diabetes Service developed individualised diets for around 60 people with Type 2 Diabetes for the six-month study. The diets were based on the core food groups of cereals and breads, fruit and vegetables, lean meat, fish, low-fat dairy products, oils, avocadoes, peanut butter and nuts. Each diet in the treatment group included 30g of walnuts (equivalent to around 8-10 nuts) per day.

The diets were carefully modelled to balance all the other dietary factors such as carbohydrates, proteins, calories and fats from the other foods to ensure the benefit was correctly attributed to the walnuts.

“The walnuts took the guesswork out of getting the right fats into the diet. We knew walnuts would deliver,” Professor Tapsell said. “Thus, people with type 2 diabetes could ask their doctor or dietitian about the benefits of including walnuts in their dietary management.”

Professor Tapsell said the study had been important because it confirmed the theoretical benefits of a certain food. “Food companies need this kind of research because it assists them in making legitimate claims about the benefits of certain foods. This particular research finding is also useful for doctors and dietitians when they provide advice to people on how to get good fatty acids into their diets,” she said.