Peanuts: An Inexpensive Health Secret Weapon

Some people erroneously avoid nuts because of their high fat content, but when portioned reasonably, these mono- and polyunsaturated fat-rich, all-natural treats can and should be a regular dietary staple.

Tree nuts like almonds, pecans and walnuts are gaining attention for their robust quantities of vitamins and minerals, alongside their LDL cholesterol-lowering unsaturated omega-3 fatty acids. Eating these nuts may reduce your risk of developing blood clots that can cause a fatal heart attack. Because they are so packed with nutrients within their tiny shells, an ounce a day of nuts (about a quarter cup or a small handful) is a generally healthy portion. Nuts also appear to improve the health of the lining of your arteries. And all nuts contain fiber, which binds to and helps remove dietary fat as the fiber passes through your body.

A legume that acts like a nut
The peanut is not a tree nut; it is a legume. Peanuts are more closely related to soybeans and lentils than to almonds and walnuts. Botanically, peanuts are not nuts—but nutritionally it turns out that they are very similar to tree nuts.

Daniel Pendick, the executive editor of Harvard Men's Health Watch, points out in the Harvard Health Blog that a study published online in March in JAMA Internal Medicine “puts the humble peanut squarely in the same nutritional league as its upscale cousins. This work makes the health benefits of nuts more accessible to lower-income shoppers.” The downside to tree nuts, after all, is that they can be expensive.

Pendick reports that an international team of researchers found that in more than 200,000 people worldwide, those who regularly ate peanuts and other nuts were substantially less likely to have died of any cause—particularly heart disease—over the study period than those who rarely ate nuts.

Controlling for genes through diversity
The JAMA Internal Medicine study looked at nut and peanut consumption in two large groups of people spanning geographic, racial, ethnic, and income boundaries:

  • 72,000 Americans, ages 40 to 79, living in 12 Southern states. Most lived on low incomes and two-thirds were African American.
  • 135,000 men and women in Shanghai, China, ages 40 to 74.

The researchers used surveys to tally nut and peanut consumption. They followed the groups for several years and counted how many participants died and from what causes. In the U.S. Southern states group, those who regularly ate peanuts were 21% less likely to have died of any cause over a period of about five years. In the Chinese groups, who were followed for six to 12 years, the death rate in nut-eaters was 17% lower.

For all the groups, the researchers accounted for unhealthy influences like smoking, obesity, high blood pressure and diabetes, which were especially common in the Southern states group.

Daniel Pendick writes, “The diversity of the participants in this new study is important. Those in the earlier Harvard studies were mostly white health professionals who were more educated and earned higher incomes than most people in the Southern states group. And in studies that just observe large groups of people over time and what they eat, such as the Harvard studies, scientists can’t be certain whether any health improvements have more to do with the participants’ lifestyles or genes rather than what the food is doing. Seeing the same health benefit across diverse groups can be reassuring.”

Though observational studies can never be sure of exact causation, eating peanuts appears to be just as potent for preventing heart disease as eating other nuts. Since peanuts generally cost less than premium tree nuts, people on lower incomes can reap the health benefits of nuts on a budget.

Harvard Health Blog, “Peanuts Linked to Same Heart, Longevity Benefits as More Pricey Nuts,” by Daniel Pendick, March, 2015, http://tinyurl.com/onoj5on

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