A recent study by researchers from the University of Georgia has found that tree nuts have even more heart-healthy nutrients than previously thought.
The researchers studied healthful constituents of ten tree nuts: almonds, black walnuts, Brazil nuts, cashews, English walnuts, hazelnuts, macadamias, pecans, pine nuts, and pistachios. (Peanuts are legumes – not tree nuts). They found that the percentage of heart-healthy fats to be primarily unsaturated oleic and linoleic fatty acids.
Most of the nuts maintained lower than 10% saturated fats, except for Brazil nuts (24%), cashews (21%), macadamias (17%), and pistachios (13%). These are also known as the more fatty nuts.
The tree nuts also contained heart-healthy tocopherols (natural form of vitamin E), which ranged from 1 to 33 milligrams for every 100 grams of the nut meat.
The researchers also found that six nuts also contained tocotrienols (another type of natural vitamin E): Brazil nuts, cashews, English walnuts, macadamias, pine nuts, and pistachios.
They also found that all the nuts contained significant phytosterol content, and mostly above the levels that have been reported in the USDA National Nutrient Database for Standard Reference.
Heart-healthy phytosterol content was highest in pistachios, containing over 300 milligrams for every 100 grams of the nut meat. Pine nuts came in second, with 272 mg/100 g nutmeat.
While tree nuts are most known for great protein sources – most having all the essential amino acids – a number of studies have confirmed that diets with more nuts provide cardiovascular prevention. The reasons, as this study presents, are their lipid content, phytosterol content, and tocopherol and tocotrienol content.
Robbins KS, Shin EC, Shewfelt RL, Eitenmiller RR, Pegg RB. Update on the Healthful Lipid Constituents of Commercially Important Tree Nuts. J Agric Food Chem. 2011 Oct 27.