Almonds, Glycemic Index, Dietary Antioxidants and Risk Factors for Coronary Heart Disease

Abstract

Background Low glycemic index (GI) diets may be of benefit in reducing risk of coronary heart disease (CHD) and diabetes, possibly by reducing postprandial glucose, insulin and oxidative stress. Objective To assess whether almonds reduce the glycemic response, insulinemia, and oxidative stress more than the same reduction by a low GI food (parboiled rice) without endogenous antioxidants. Methods Two studies were undertaken. The first study (n=10) assessed the dose-response effect of almonds in reducing postprandial glycemia. The second study (n=15) assessed a high GI meal (mashed potatoes) compared to two low GI meals (parboiled rice, almonds) on postprandial glucose, insulin and measures of oxidative stress. All meals contained 50g available carbohydrates and were balanced for protein and fat. Results The first study found that 60g almonds significantly reduced the glycemic response of white bread. In the second study, the glycemic responses (mean±SE) of the low GI almond (54.5±6.9, P<0.001) and rice (37.5±6.3, P<0.001) meals were significantly reduced compared to white bread, while the high GI potato (94.3±11.1, P=0.61) meal showed no significant difference. Insulin values reflected the glycemic responses. Protein thiols tended to be higher following the almond meal indicating less oxidative damage. Conclusion Low GI foods lower postprandial glycemic and insulinemic response curves, and tend to reduce oxidative stress. Preliminary data indicate that low GI foods as part of a healthy diet may reduce risk factors for CHD and diabetes. Support: Almond Board of California