They’re good for us, but which nut
is the best?
Health-conscious people are mad about nuts these days. The enthusiasm
comes from a steady drumbeat of studies over the past decade showing
that they’re genuine health food. Their most salient effect seems
to be heart attack prevention. Some studies suggest they give you some
protection against diabetes, too.
True, nuts are high in calories: Just an ounce of most varieties has
more than the 140 or so calories contained in 12 ounces of many brands
of soda. Ideally, you should incorporate them into regular meals as a
protein source. About 80% of the calories come from fat. Much of the
fat, though, is “good” monounsaturated and polyunsaturated
fat, not the “bad” saturated variety in meat and dairy products — or
worse yet, dreaded trans fat. In research studies, cholesterol-lowering
diets that contain nuts reduce “bad” LDL cholesterol by 9%–20%,
regardless of the amount of fat or nuts.
Other healthful ingredients in nuts include copper, fiber, folate, and
vitamin E. They have lots of arginine, an amino acid that the body uses
to make nitric oxide. Nitric oxide relaxes blood vessels so blood flows
easily. An ounce of most varieties of nuts has about 10%–20% of
the recommended daily intake of magnesium. Studies have shown that many
Americans don’t get enough of the mineral, with average intake
falling about 100 milligrams shy of daily recommendations (420 mg for
men, 320 mg for women). Magnesium is important to maintaining the proper
proportion of calcium to potassium. Also, low levels of magnesium in
the diet may contribute to heart attacks and hypertension.
Which nut comes out on top? Almonds, peanuts, walnuts — each
has its own association or board, primarily composed of growers and related
companies. Of course health claims are a major selling point. So the
associations sponsor studies of their particular nut’s boon effects
on cholesterol levels, blood vessels, and other cardiovascular factors.
Competing studies are difficult to compare. But the United States Department
of Agriculture has a database of the nutrient content of individual foods
that sheds a little light on the subject. Almonds have slightly more
vitamin E than walnuts, and much more magnesium. Walnuts, stand out as
the only nut with an appreciable amount of alpha-linolenic acid, the
only type of omega-3 fat you’ll find in a plant-based food. Peanuts
(which technically are legumes) lead in the folate category. Cashews
have even more magnesium than almonds (83 milligrams per ounce vs. 73)
but they lag behind in vitamin E. If it’s selenium you’re
after — as many men are, because the mineral might protect against
prostate cancer — then look to Brazil nuts: One ounce has almost
10 times the Recommended Dietary Allowance (RDA) of 55 micrograms. When
it comes to taste, macadamia nuts are hard to beat. But they’re
also high in saturated fat (3.4 grams per ounce) compared with other
Nobody has done a comprehensive side-by-side comparison of the cholesterol-lowering
effect of nuts. But citing individual studies, the authors of an almond
study published in Circulation a couple of years ago said that,
ounce for ounce, walnuts, peanuts, and pistachios are equally effective.
Almonds are a close second, they said. Pecans and macadamia nuts, which
are a bit higher in calories, lagged far behind.
So far, no nut is the clear hands-down winner. But there is always the
noncompetitive approach: mixed nuts. Unsalted, of course.
October 2004 Update
Back to Previous Page