"To put it simply, a healthy artery is like an elastic rubber pipe that allows changes in flow, while an artery with impaired endothelial function is like a rigid lead pipe that has a constant flow. The walnut diet in this study actually restored the elasticity of the artery, allowing increased blood flow on demand," explains Dr. Ros. "Anyone who has risk factors for heart disease, such as smoking, high blood cholesterol, diabetes, hypertension or obesity, is in a situation where the arteries do not dilate properly when they need to. That's what is called endothelial dysfunction. The patients in our study had high blood cholesterol, a known cause of endothelial dysfunction, and this abnormality was corrected by the walnut diet. The encouraging results of this study provide physicians and patients with a powerful, yet simple, nutritional tool in their fight against heart disease," he says.

Conducted by the Lipid Clinic at the Hospital Clinic of Barcelona, the study is entitled, "A walnut diet improves endothelial function in hypercholesterolemic subjects: a randomized crossover trial." 21 men and women (ages 25-75) with high cholesterol followed a cholesterol-lowering Mediterranean diet, and a diet of similar energy and fat content in which approximately 1.4-2.3 ounces of walnuts daily (equivalent to 40-65 grams or 8-13 walnuts), based on subjects' total caloric intake, replaced roughly 32 percent of the energy from monounsaturated fat. Participants followed each diet for four weeks.

University of Barcelona is one of the two most productive scientific institutions in Spain according to statistics recently published by the European Union. With regard to scientific output, the Hospital Clinic of Barcelona is among the top 10 leading hospitals in the European Union and is first place among hospitals in Spain.