Walnut advice helps diabetics protect their hearts
helps them achieve a dietary fat profile with optimal amounts of
polyunsaturated fatty acids, which helps protect against heart
disease, say researchers in Australia.
A study at the University of Wollongong's Smart Food Center, published in the July issue of the Journal of the American Dietetic Association, set out to test the clinical feasibility of advice strategies aimed at increasing the fatty acid intake of type-2 diabetes patients.
Such patients are advised to consume dietary fats that have been shown to deliver cardiovascular health benefits - that is unsaturated fatty acids in place of trans- and saturated fats.
The American Diabetes Association estimates that 18.2 million percent of Americans suffer from the disease (6.3 percent of the population), the majority of whom have type-2 diabetes. Only around 13 million of these have actually been diagnosed, however.
On a worldwide basis, the WHO reports that at least 171 million people have diabetes, but incidence is on the increase and the figure is expected to reach 366 million by 2030.
One of the complications arising from diabetes is an increased risk of cardiovascular disease. In fact, 65 percent of diabetes patients in the US die of heart disease. Diabetes can also lead to blindness, nerve damage and kidney damage.
According to lead researcher Lynda Gillen, an important aspect of weight management for diabetics is the achievement of energy balance despite increased intake of high fat foods.
Gillen's trial involved 55 men and women with type-2 diabetes, who were randomly assigned to one of three groups. One group was advised to follow a general low-fat diet, a second to follow a modified low-fat diet, including foods rich in polyunsaturated fatty acids (PUFAs) and a third to follow a diet including 30g of walnuts, making up 31 percent of dietary fat, plus 350g of oily fish a day.
The team observed that few of the participants were consuming sufficient amounts of PUFAs at baseline, with meat making up 22 percent of total dietary fat. It set out to track whether advice to include walnuts in the diet would result in free-living patients being able to follow a low-fat energy-controlled diet with optimal dietary fat proportions.
At three months, the walnut and fish group had the greatest proportion of subjects achieving PUFA targets and these were maintained for longer.
After six months, those in the walnut group were consuming almost half their dietary fat intake from PUFA-rich foods. Walnuts provided almost one third of total fat intake and one half omega-3 polyunsaturated fat intake. The low fat group, on the other hand, continued to consume foods rich in saturated fat as the main sources of fat in the diet.
The conclusion drawn from this was that specific advice for the regular inclusion of walnuts in the total diet could help type-2 diabetes patients achieve optimal fat intake proportions without adverse effects on total fat or energy intakes.
"Individuals consuming walnuts were more likely to achieve a beneficial fat profile than those consuming a larger quantity of oily fish (500g/wk) or those following standard 'low fat' advice," said Gillen.
The study results have been commended by professions in the field of diabetes care.
"It is important and challenging, for people with type 2 diabetes to eat the right types and balance of fats," said Marion Franz, former director of nutrition and health professional education at the International Diabetes Center.
"The fact that achieving nutrition goals became easier by including walnuts is helpful and useful news for persons with diabetes, and the clinicians and diabetes educators who provide nutrition counsel."
