Walnuts May Help Protect the Heart of Diabetics
The daily consumption of walnuts may help improve the function of the blood vessels and decrease both total and bad cholesterol in patients with type 2 diabetes, according to a study presented at the American College of Preventive Medicine (ACPM) annual meeting and published in the February issue of Diabetes Care.
The small trial involved 24 diabetic patients, 14 women and 10 men, with a mean age of 58 years. Those in the intervention group received a diet enriched with 56 grams of walnuts per day (about ¼ cup).
Those consuming the daily serving of walnuts showed a significant improvement to flow-medicated dilatation, meaning that when blood flowed through the vessel, it appropriately dilated, decreasing the force on the epithelium, or inner lining of the blood vessels. The walnut-eaters also had a reduction in total cholesterol and LDL cholesterol levels.
Walnuts are an excellent source of omega-3 fatty acids – a quarter-cup provides 90% of the daily value. These fats have been shown in previous studies to have many cardiovascular benefits such as preventing blood clotting, reducing inflammation that promotes atherosclerosis, and improving the ratio of HDL to LDL cholesterol. Walnuts also contain arginine, an essential amino acid that may be beneficial to reducing hypertension.
The U.S. Food and Drug Administration has recently cleared the health claim that "eating 1.5 ounces per day of walnuts as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease."
Diabetic measures were also evaluated, including HbA1C, fasting blood glucose, and insulin sensitivity, but researchers did not find any significant differences between the intervention and the control groups. The additional calories provided by the walnut serving, about 365 per day, did not result in any significant weight gain.
"If you're adding a nutritious food to the diet, the benefits of the food might sometimes be offset if weight gain occurs, and obviously, with diabetics, the last thing you want to do is cause weight gain," lead researcher Dr. Katz explained. "But our study suggests you can make room for a highly nutritious food in your diet, particularly if it tends to fill you up, as nuts do."