Walnuts may be heart-healthy nuts

According to Spanish researchers, walnuts may be heart-healthy nuts. While both raw walnuts and olive oil decreased the sudden onset of arterial inflammation and oxidation after an unhealthy meal, the walnuts were better at keeping arteries flexible, they found.

But patients should not take this as an excuse to regularly eat fat-filled meals, followed by a handful of walnuts, said Emilio Ros, M.D., Ph.D., of the Lipid Clinic at Hospital Clínico here, and colleagues, in the Oct. 17 Journal of the American College of Cardiology.

The study, they pointed out, was small, and it looked at the effect of a single meal on individuals whose regular fare was a healthy Mediterranean diet, reports MedPage Today.

According to News-Medical, the Spanish researchers by using ultrasound examinations were able to see that both the olive oil and the walnuts decreased the onset of inflammation and oxidation in the arteries following a high-fat meal, but the walnuts preserved the blood vessels' flexibility while olive oil did not.

Lead researcher Dr. Emilio Ros, director of the clinic attributes the beneficial effect to the alpha-linolenic acid found in walnuts which is similar to the omega-3 fatty acids found in fish.

Dr. Ros said: "Many people forget that walnuts are an important part of the Mediterranean diet, providing numerous health benefits."

The Med diet, rich in cereals, fruits, nuts, legumes and whole grains, fish and olive oil, has been linked to longer life, less heart disease, and protection against some cancers. The diet's main nutritional components include beta-carotene, vitamin C, tocopherols, polyphenols, and essential minerals.

In fact, "walnuts, unlike olive oil and other nuts, contain significant amounts of polyunsaturated fatty acids, specifically alpha-linolenic acid (ALA), an essential plant based omega-3. They also provide antioxidants and L-arginine, components identified in past studies as potential nutrients that improve artery function,” he said.

Robert Vogel, a researcher from the University of Maryland, who did not participate in the study, said: "This demonstrates that the protective fat from walnuts actually undoes some of the detrimental effects of a high-saturated-fat diet, whereas a neutral fat, such as olive oil, does not have as much protective ability.

"This raises a very interesting issue because many people who eat a Mediterranean diet believe the olive oil is providing the benefits. But this research and other data indicate that's not true.

“There are probably other factors in the diet, including that it is a relatively rich source of nuts. This is not to say that olive oil is bad, but it's not the key protective factor in the Mediterranean diet," said Vogel in a statement, informs Nutraingredients.