Walnuts, Cholesterol, LDL & Triglycerides
Walnuts are rich in anti-inflammatory nutrients, including omega-3 fatty acids and ellagic acid. Previous research has shown that the regular consumption of walnuts appears to improve cardiovascular function following high-fat meals. In diabetics, who face an increased risk of cardiovascular disease, walnuts also appear to improve cardiovascular function.
A newly published prospect, randomized clinical research trial, which appears in the European Journal of Clinical Nutrition, evaluated the effects of a walnut-supplement diet on 87 adults with normal-to-high cholesterol levels in their blood. This study used a "crossover" approach, in which all of the patient volunteers received walnut supplements for 6 months, and were then switched to a walnut-free diet for another 6 months. During this 12-month study, blood tests were performed at the beginning of the study, and then at 4, 6, 10 and 12 months into the study. Because of the crossover design of this study, the researchers were able to directly compare the effects of walnut supplementation on body weight, total cholesterol, LDL cholesterol (the "bad cholesterol"), HDL cholesterol (the "good cholesterol"), and fatty acids (triglycerides). Together, these compounds are referred to as "lipids."
As has been observed in previous clinical studies of shorter duration, this study found that a 6-month period of walnut supplementation resulted in significant reductions in total cholesterol and triglyceride levels. LDL levels were also reduced, although this finding just barely failed to reach statistical significance. Importantly, these favorable changes in blood lipid levels were found to be more pronounced in patients with elevated total cholesterol and LDL cholesterol levels. I should note that significant reductions in LDL blood levels have been observed in response to adding walnuts to the diet of patients with elevated LDL levels, in other studies.
While statins, and other lipid-lowering drugs, have revolutionized the management of elevated cholesterol and triglycerides, and have been shown to significantly reduce the risk of cardiovascular disease (and death due to cardiovascular disease), not all patients with hyperlipidemia can tolerate these drugs . Moreover, as with all medications, these lipid-lowering drugs are not equally effective in all patients, and many patients with hyperlipidemia will continue to have elevated LDL cholesterol and / or triglyceride levels since taking lipid-lowering drugs.
Studies such as this one suggest that the addition of walnuts to one's diet may be a useful adjunct in lowering elevated LDL cholesterol and triglyceride levels. (As always, I encourage everyone to check with their doctor before making any significant alterations in their diet, especially if you have one or more chronic illnesses.)
For a detailed and comprehensive assessment of the role of nuts, omega-3 fatty acids, ellagic acid, and other dietary modifications, as part of a cancer prevention lifestyle, look for the publication of my new book, "A Cancer Prevention Guide for the Human Race, "in the spring of this year.