Legend says the Queen of Sheba loved pistachios. But modern health fans may swoon more about the boost to heart health this pea-sized nut offers to type 2 diabetics, according to recent findings in the Journal of the American Heart Association.

For the study, researchers first fed patients who had well-controlled type 2 diabetes a typical American diet for two weeks. Next, scientists supplied participants with a standard heart-healthy diet along with about 150 pistachios (half salted, half unsalted) each day. Then, researchers measured blood pressure—in the lab and in a real-world setting—as well as blood vessel resistance during two stress tests. (In one test, participants dunked one hand into icy water for two minutes; in the other, they engaged in a challenging and confusing mental arithmetic test.)

Findings showed participants who ate the diet with pistachios as a treat suffered a much less negative physical response to the stresses of both tests compared with those who didn’t eat the nuts. In adults with diabetes, two servings of pistachios each day reduced tightening of the blood vessels during stress and improved the nervous system’s control of the heart.