The Role of Nuts in Coronary Heart Disease

Coronary heart disease (CHD) is the leading cause of death worldwide. The basis for developing CHD is the onset and progression of atherosclerosis caused by abnormal lipoprotein metabolism and uncontrolled cycles of inflammation and oxidative stress. Risk factors for the manifestation of atherosclerosis and consequent development of CHD remain to be hypertension, poor dietary habits, hypercholesterolemia, smoking, diabetes, and obesity. Strong evidence suggesting that dietary patterns, such as the Mediterranean diet or the consumption of fruit and vegetables, play an important preventative role against CHD have generated much interest in elucidating the “optimal” diet for the prevention of CHD. Among foods that are considered to be cardioprotective, nuts have generated considerable interest in the last decades. First investigated by Fraser et al. in 1992, individuals who consumed nuts had significantly lower risks of non-fatal myocardial infarction and fatal coronary events compared to those who did not consume nuts. Subsequent large epidemiological investigations and intervention studies corroborated this finding and have consistently demonstrated that nut consumption protects against CHD. In light of the substantial evidence, nuts have been recommended by the American Heart Association since the year 2000 and were approved for a qualified health claim for reducing the risk of CDH by the Food and Drug Administration in 2003. The strong epidemiological evidence supporting the role of nuts in reducing the risk of CHD has inspired many investigations elucidating their mechanisms of action. In vivo and in vitro evidence suggests that nuts influence lipoprotein and lipid metabolism, atherosclerosis, and oxidative stress in a cardioprotective manner. These beneficial effects are generally ascribed to the ideal nutrient composition of nuts. Nuts are energy dense and are a source of monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA), protein, fiber, folate, vitamins E and K, potassium, selenium, magnesium, and copper. They also contain a vast array of bioactive compounds such as catechins, resveratrol, flavonols and flavonones.