Pistachios are about 20 percent protein and 50?55 percent fat and have good levels of thiamine, niacin, folic acid, and a little vitamin A. The potassium and iron levels are both very high; sodium is very low; phosphorus, magnesium, and calcium are all present in pretty fair amounts; while zinc, copper, and manganese are at modest levels.

Walnuts . Another of the great nuts, walnuts are a real brain food (they even look like little brains). The fatty acids and the 15?20 percent protein level nourish the nervous system, and the walnut when shelled looks remarkedly like the human cerebral cortex. The walnut is about 65 percent fat. It can be eaten raw or used in baking, and the pressed walnut oil can be used in cooking or even for oiling wood. It should be used fresh, though, as it is not very resistant to spoilage.

Walnuts have a modest mix of vitamin A, the Bs (including biotin), C, and E. Their mix of minerals is similar to that of most of the other nuts, with many at good levels. Probably iron and potassium are the best in this very balanced nut, which grows on large trees as high as 40?50 feet in many parts of the world, including the United States.