Nuts are concentrated sources of protein, healthy unsaturated oils, omega-3s, sterols, trace minerals and more. In a nutshell, they’re a whole lot of health.
Studied for decades, nuts have had their nutritional value pretty well established. But they’re also nutrient-dense, which means high calories. Some believed this trade-off means nuts should still be used sparingly. New research not only indicates the benefits of nuts outweigh any caloric load, they don't necessarily lead to weight gain either.
For example, research conducted on walnuts at Loma Linda University (Calif.) School of Public Health is just one of a number of studies on the connection between satiety and nuts.
"Walnuts help alleviate hunger (providing) many essential nutrients for a relatively small percentage of daily calories," said Joan Sabate, M.D., chair and professor of nutrition at the university. According to the study, eating even a few walnuts before meals decreased reported levels of hunger in subjects and could influence consumption of fewer total calories at meals.
There's More Inside
Nuts are excellent sources of vitamin E and contain folate and heart-healthy B vitamins as well. Walnuts are an especially good source of alpha-linolenic acid, a plant-derived omega-3 fatty acid.
Nuts are also a good source of plant protein and the amino acid arginine, shown to have beneficial effects on vascular health. They also are an excellent source of trace minerals such as magnesium and selenium. (see "Without a Trace.")
Nuts and peanuts are a source of plant sterols known to block cholesterol absorption and stimulate increased excretion of bile acids, two metabolic mechanisms which decrease LDL cholesterol levels. Also, nuts - including peanuts - are a good source of dietary fiber.
The Almond Board of California detailed a number of new studies that increase the attraction of this already popular nut. Almond board figures show the nut appeared in a record number of primary, secondary, private label and non-food products in 2004 (the most recent year for which data are available).
The research the board cites includes evidence almonds help reduce inflammation of blood vessels by about the same level as taking a first-generation statin drug.
The antioxidants in almonds are also a unique combination, featuring 20 identified flavonoid compounds alone, including catechins like those found in green tea, and a particularly high level of vitamin E. Both of these components "could have significant health implications, especially as people age," according to the almond board.
Not Some Kind of Nut
Although botanically a legume, peanuts are king of the nuts when it comes to consumption in the American diet. And the health benefit of the "lowly ground nut" is significant.
|A recent study suggests walnuts can boost blood levels of antioxidants and the hormone melatonin - at least in lab animals. Melatonin, naturally produced in the pineal gland, is connected with inducing and regulating sleep, and supplements of the hormone have become popular as a natural sleep aid and reliever of jet lag. In humans, melatonin levels diminish as we age. An insomnia prescription could soon read, "Take two walnuts and call me in the morning."|
"On the basis of the epidemiologic literature, there is a large data base showing a dose-response relationship between nut consumption and reduced risk of cardiovascular disease (CVD)," says Penny Kris-Etherton, Ph.D., distinguished professor of nutrition at Penn State University, University Park, Pa. "In fact, consuming nuts and peanuts five times a week or more decreases risk of CVD 40 to 50 percent. A recent study has shown as little as two servings per week decreases risk of sudden death.
Research on peanut butter suggests a protective effect against diabetes and gallstone risk, too, according to Kris-Etherton. One study showed that five or more servings of peanuts and/or peanut butter per week decreases risk of type 2 diabetes by 21 percent, and one to four servings per week decreases risk about 10 percent.
Controlled clinical studies consistently show nuts and peanuts lower total and LDL cholesterol levels. In addition, they increase HDL cholesterol and decrease triglycerides with a low fat diet. Thus, a moderate fat (with monosaturated and polyunsaturated fats from nuts and peanuts) diet that is low in saturated fat and cholesterol decreases risk of CHD more so than does a low fat, blood cholesterol lowering diet.
Nuts, peanut butter and nut butters are often associated with weight-gain risk because of their high fat content. Yet research shows the opposite to be true.
"High consumers of nuts and peanuts have a lower body mass index - not a higher one - compared with non-nut and non-peanut consumers," notes Kris-Etherton. "Nuts and peanuts are calorically dense. However, when eaten in moderation and incorporated in the diet to meet energy needs, there is no reason to expect weight gain," she explains. It should be noted that nut and peanut calories are like any other, in that if added to daily calories instead of substituted, weight gain is a risk.
"The fat from nuts is a heart-healthy fat that is an excellent means to decrease risk of chronic disease, notably heart disease, says Kris-Etherton." Nuts and peanuts also deliver many nutrients that help achieve nutrient adequacy of the diet, and promote health."