A new study from Penn State suggests that eating a few walnuts daily can help counteract unhealthy responses to stress, including rising blood pressure. The 22 healthy adult participants all had previously diagnosed high cholesterol and were provided all their meals and snacks during three diet periods of six weeks each. One diet period reflected "an average American" plan containing no nuts; a second substituted 1.3 ounces of walnuts and a tablespoon of walnut oil for some of the fat and protein in the average American diet; the third diet added 1.5 tablespoons of flaxseed oil to the second version. The calories in all three diets were calibrated to avoid weight loss or gain. After each diet period, the participants took two stress tests: the first was a three-minute videotaped speech given after only two minutes preparation; the second was a standard stress test in which one foot is submerged in ice-cold water. Blood pressure readings taken during the tests showed that the "bottom" (diastolic) number was significantly lower after consuming the diet that incorporated walnuts and walnut oil. Adding flaxseed oil didn’t further reduce blood pressure but did lower C-reactive protein, a marker for inflammation in the blood; it also improved artery dilation, a positive change, seen on vascular ultrasound.
My take? This is further evidence that walnuts are good for you (as long as you don't overdo it -they're relatively high in calories). Earlier studies have shown that adding walnuts to the diet is beneficial to heart health, and the FDA permits this qualified health claim on packages of walnuts: eating 1.5 ounces daily "as part of a low saturated fat and low-cholesterol diet, and not resulting in increased caloric intake, may reduce the risk of coronary heart disease." I usually eat a handful of walnuts a day.
Try Garlic Walnut Dip at your next dinner party, or just for an everyday snack.