The Scientific Evidence for a Beneficial Health Relationship between Walnuts and Coronary Heart Disease
This report was prepared by the LSRO for the California Walnut Commission. Authored by Elaine B. Feldman, M.D., Professor Emeritus Medical College of Georgia, and reviewed by four independent experts, the intent and quality of scientific evidence are evaluated for a potential beneficial health relationships between the intake of walnuts and the reduction and prevention of coronary heart disease. The report also addresses the supporting evidence for the health benefit of other tree nuts and selected legumes. Dr. Feldman and the LSRO Expert Panel of reviewers followed the FDA guidance document regarding the significant scientific agreement standard for the relationship between a food substance and a disease or health-related condition (Food and Drug Administration. Center for Food Safety and Applied Nutrition, 2000).
Conclusions of the report are that walnuts, as part of a heart-healthy diet, lower blood cholesterol concentrations in humans and animals. Compared to most other nuts, which contain monounsaturated fatty acids, walnuts are unique because they are predominate in n-6 (linoleate) and n-3 (linolenate) polyunsaturated fatty acids. Walnuts contain multiple health-benefit components, such as having a low lysine:arginine ratio and high levels of arginine, folate, fiber, tannins, and polyphenols. Furthermore, clinical dietary intervention studies show that walnut consumption does not cause a net gain in body weight when eaten as a replacement food. Human clinical walnut intervention studies suggest reduced relative risk of coronary heart disease. Yet, these studies are inconclusive because only five controlled, peer-reviewed, published trials with few subjects were identified. However, the existing studies considered in their totality, represent 51% of the adult human population in the United States at higher risk of coronary heart disease and suggest that walnuts, as part of a heart-health diet, lower blood cholesterol concentrations. This strong trend needs to be substantiated.
You can download the report, which was published as a Supplement to the Journal of Nutrition in May 2002, in PDF format.
