Nuts: consumption, composition, health benefits and safety.

Abstract

Abstract Nuts are nutrient-dense foods rich in unsaturated fatty acids; most nuts contain monounsaturated fatty acids, whereas walnuts are rich in both n -6 (linoleic acid) and n -3 (α-linolenic acid) poly-unsaturated fatty acids. The complex matrices of nuts contain many bioactive compounds: vegetable protein (including L-arginine, the amino acid precursor of nitric oxide the endogenous vasodilator), fibre, minerals, tocopherols and phytochemicals, such as phytosterols and phenolic compounds. By virtue of their unique composition, nuts are likely to beneficially impact health outcomes. Epidemiological studies have consistently associated frequent nut intake with a reduced incidence of coronary heart disease. Decreased rates of sudden cardiac death and diabetes development in association with nut consumption have also been reported. Many small feeding trials have clearly demonstrated that intake of all kinds of nuts has a cholesterol-lowering effect, even in the context of healthy diets. There are emerging evidences that nut consumption has a positive effect on oxidative stress, inflammation and vascular reactivity. Blood pressure, visceral adiposity and the metabolic syndrome also appear to be positively influenced by nut consumption. Thus, it is clear that nuts beneficially impact cardiovascular risk factors beyond cholesterol lowering. Contrary to expectations, epidemiological studies and clinical trials suggest that regular consumption of nuts is unlikely to contribute to obesity or increase the risk of diabetes. Safety concerns are limited to the infrequent occurrence of nut allergy in children. In conclusion, nuts are densely packaged nutrients with wide-ranging cardiovascular and metabolic benefits, which can be readily incorporated into healthy diets.