Pistachios may lower vascular response to stress in type 2 diabetes

Among people with type 2 diabetes, eating pistachios may reduce the body’s response to the stresses of everyday life, according researchers. “In adults with diabetes, two servings of pistachios per day lowered vascular constriction during stress and improved neural control of the heart,” said the lead investigator. “Although nuts are high in fat, they contain good fats, fiber, potassium and antioxidants. Given the high risk of heart disease in people with diabetes, nuts are an important component of a heart healthy diet in this population.”

After two weeks on the typical American diet — containing 36 percent fat and 12 percent saturated fats — participants were randomized to one of two test diets. During the four-week test diets, participants ate only food supplied by the study. The researchers reported the results of this study in a recent issue of the Journal of the American Heart Association.

Test diets included a standard heart-healthy diet — 27 percent fat and 7 percent saturated fat — and a diet containing two servings per day of pistachios — about 3 ounces or 20 percent of calories from pistachio nuts. The typical research participant consumed about 150 pistachio nuts per day. The pistachio diet contained 33 percent fat and 7 percent saturated fat. Half of the nuts consumed each day were salted and half were unsalted. At the end of each four-week diet period, the researchers measured blood pressure and total peripheral vascular resistance at rest and during two stress tests — a cold water challenge and a confusing mental arithmetic test.

Although laboratory measurements of blood pressure were not affected by pistachios, real-world measures of blood pressure (measured by an automated monitor) were significantly lower after the pistachio diet. Katherine A. Sauder, former graduate student in biobehavioral health, conducted these measurements.