Cholesterol, a waxy, fatty substance manufactured by the liver but also found in foods, is essential to the body. Excess levels of cholesterol, however, can build up on the sides of blood vessels and cause blockages. Some foods, including several types of nuts, can help reduce high cholesterol levels and thereby reduce the risk of heart disease. Nuts appear to help lower cholesterol because they contain unsaturated fats and omega-3 fatty acids, as well as L-arginine, which improves flexibility of blood vessels and decrease blood clot formation. Nuts also contain fiber, which reduces cholesterol levels.
Walnuts
The Food and Drug Administration suggests that eating 1.5 oz., or 42 g of walnuts a day may reduce the risk of heart disease, although conclusive proof is still lacking. Walnuts, one of the best studied nuts in respect to cholesterol levels, according to the Mayo Clinic, have very high levels of omega-3 fatty acids, essential fatty acids that the body can't manufacture; they must be obtained from foods. Omega-3 fatty acids reduce inflammation and also help prevent heart disease.
Almonds
Almonds also may help lower cholesterol levels. An article published by lead author David J.A. Jenkins, M.D., of St. Michael's Hospital, Canada, in Circulation, an American Heart Association publication, in 2002, reported an overall reduction in low-density lipoprotein cholesterol levels, the "bad" cholesterol, of around 1 percent per 7 g of almonds after review of several studies. Almonds, like other nuts, are high in both calories and fat, so eating almonds as a substitute for other high fat foods such as cheese or meat helps keep calories within a normal range while reducing cholesterol levels.
Pecans
Pecans, like walnuts and almonds, have also been found to lower cholesterol levels in studies. An ounce of pecans is slightly higher in calories and fat than most other nuts, the Mayo Clinic reports. Although pecans consist of 70 percent fat, according to nutritionist Leslie Beck, the fat they contain is beneficial unsaturated fat. Pecans also supply large amounts of anti-oxidants and vitamin E, which may slow oxidation of LDL cholesterol. This type of cholesterol may stick more readily to artery walls, Beck adds.
References
- MayoClinic.com: High Cholesterol
- Leslie Beck, RD: Pecans
- MayoClinic.com: Nuts and Your Heart
- Food and Drug Administration: Qualified Claims About Cardiovascular Disease Risk
- "Circulation": Dose Response of Almonds on Coronary Heart Disease Risk Factors: Blood Lipids, Oxidized Low-Density Lipoproteins, Lipoprotein(a), Homocysteine, and Pulmonary Nitric Oxide ; D. Jenkins, M.D. et al; 2002
