Studies have shown walnuts boost endothelial function, and now new research indicates walnuts may even be better for the cardiovascular system than olive oil.
In Barcelona, investigators randomized 24 nonsmoking, middle-aged, healthy adults to one of two groups of 12. Each group was provided with two high-fat meals, eaten under supervision one week apart. The meals were identical, consisting of a salami-and-cheese sandwich on white bread and a small serving of full-fat yogurt. For one meal, the researchers added about five teaspoons (25 mL) of olive oil. For the other meal, they added 40 g of walnuts, or about eight shelled nuts.
Both the olive oil and the walnuts lessened the sudden onset of inflammation and oxidation in the arteries. But unlike olive oil, walnuts also helped to preserve the elasticity and flexibility of the arteries, regardless of the subject’s cholesterol levels (half the volunteers had moderately high LDL and triglyceride levels).