A Penn State study has shown that a diet rich in alpha-linolenic acid from walnuts, walnut oil and flaxseed oil not only lowered bad cholesterol but also decreased markers for blood vessel inflammation in men and women representative of typical Americans at cardiovascular risk.
While previous studies have shown that walnut supplementation favorably affects cholesterol and other lipids that are signs of cardiovascular risk, this new study is the first to demonstrate that a diet high in walnuts decreases C-reactive protein (CRP), a marker of inflammation strongly associated with heart disease.
Dr. Penny Kris-Etherton, distinguished professor of nutrition who led the study. says, "In a heart healthy diet, you need different unsaturated fatty acids that come from a variety of vegetable sources. Walnuts are a good source of two essential unsaturated fatty acids, alpha-linolenic acid and linoleic acid. They are a source of dietary fiber and a small amount of plant protein and other important vitamins and minerals. This research shows that walnuts, with their unique nutrient profile, can play a role in reducing cardiovascular risk factors as part of eating plans that also control saturated fat, trans fat, dietary cholesterol and calories."
The study is detailed in a paper, Dietary Alpha-Linolenic Acid Reduces Inflammatory and Lipid Cardiovascular Risk Factor in Hypercholesterolemic Men and Women, in the current issue of the Journal of Nutrition. The authors are Guixiang Zhao, former doctoral student in nutritional sciences at Penn State; Dr. Terry D. Etherton, distinguished professor and head of the Department of Dairy and Animal Sciences; Dr. Keith R. Martin, assistant professor of nutritional sciences; Dr. Sheila G. West, assistant professor of biobehavioral health; Dr. Peter J. Gillies, director, Health Science Strategy, DuPont Haskell Laboratory for Health and Environmental Sciences, DuPont; and Kris-Etherton.
The study included 20 men and 3 women, average age about 50, who were overweight, had moderately elevated cholesterol and LDL cholesterol and were representative of individuals at risk for cardiovascular disease. On average their total cholesterol was 225, LDL cholesterol 154, HDL cholesterol 45 and triglycerides 137 mg/dl.