In the past, many have avoided nuts because of their high fat content. The
Dietary Approaches to Stop Hypertension (DASH) diet, however, recommends re
gular consumption of this food along with seeds and dried beans (4-5 servin
gs per week) as part of a diet to control hypertension. Nuts ate nutrient-d
ense and most of their fat is unsaturated. They are also perhaps the best n
atural source of vitamin E and are relatively concentrated repositories of
dietary seer, magnesium, potassium, and arginine, the dietary precursor of
nitric oxide. Human feeding studies have demonstrated reductions of 8-12% i
n low-density lipoprotein (LDL) cholesterol when almonds and walnuts are su
bstituted for more traditional fats. Other studies show that macadamias and
hazelnuts appear at least as beneficial as fats in commonly recommended di
ets. Whether consuming modest quantities of nuts daily may promote weight g
ain is not known with certainty, but preliminary data suggest that this is
unlikely. Four of the best and largest cohort studies in nutritional epidem
iology have now reported that eating nuts frequently is associated with a d
ecreased risk of coronary heart disease of the order of 30-50%. The finding
s are very consistent in subgroup analyses and unlikely to be due to confou
nding. Possible mechanisms include reduction in LDL cholesterol, the antiox
idant actions of vitamin E, and the effects on the endothelium and platelet
function of higher levels of nitric oxide. Although nuts may account for a
relatively small percentage of dietary calories, the potential interacting
effects of these factors on disease risk may be considerable.