Nuts are a delicious part of an anti-aging diet, helping you ward off chronic diseases like cardiovascular disease, diabetes, and certain cancers—and thanks to a review of two large-scale, long-term studies published in theNew England Journal of Medicine in 2013, there’s strong evidence that nuts of all kinds can help you live longer, too. In that research, eating just an ounce of nuts daily was linked to a 20 percent lower risk of death over a 30-year period.
Further, a 2015 paper published in JAMA Internal Medicine—involving more than 200,000 people in the U.S. and China—also found that eating nuts can improve longevity.
Nuts and General Health
Nuts have been a regular component of the human diet for thousands of years. A growing body of evidence that nuts are healthy prompted the U.S. Food and Drug Administration (FDA) in 2003 to issue a qualified health claim saying that current scientific data suggest that eating 1.5 oz (42g) of nuts each day may reduce the risk ofheart disease.
More recent research has shown that eating nuts is linked to a lower risk of colon cancer, gallbladder disease, and diverticulitis, along with lower rates of some disease markers like inflammation, insulin resistance,metabolic syndrome, and dangerous belly fat.
Could Nuts Keep You Living Longer, Too?
To determine whether eating nuts might lower mortality rates, researchers from the Harvard School of Public Health, Brigham and Women’s Hospital and elsewhere examined data from two major longitudinal studies.
The first was the Nurses’ Health Study, an epidemiological investigation into lifestyle factors influencing the long-term health of women. The second data set involved male adults recruited for the Health Professionals Follow-Up Study.
Detailed diet questionnaires from more than 76,000 women and 42,000 men were compiled over three decades.
On the question of nut consumption, participants were asked how often they ate approximately a 1oz (28g) serving of nuts: never, one to three times each month, once a week, all the way up to several times per day.
After analyzing 30 years’ worth of data, the results linked eating 1oz (28g) of nuts each day to a 20 percent reduced risk of death from any cause, including cancer, heart disease, and respiratory disease.
Which Nuts Were Best?
The diet surveys asked only whether the subjects ate tree nuts like walnuts, almonds, cashews, and hazelnuts, or whether they were eating peanuts (actually a legume, not a true nut). The lowered death risk was consistent, whether participants regularly ate tree nuts or peanuts.
Weren’t these just really healthy people to begin with? Indeed, the female participants were nurses, and the male subjects recruited from health professions like optometry, dentistry, and pharmaceutical science—an intentional bias aimed at gathering adults who would be motivated and willing to make a long-term commitment to the health studies.
The research revealed that nut-eaters are generally leaner, less likely to smoke, and more likely to eat fresh produce, and get regular exercise. To account for this, the researchers adjusted for, or ruled out, many potentially confounding risk factors, such as the subjects’ overall energy intake, their consumption of alcohol and red or processed meat, activity level, body mass index, family medical history, etc.
While it’s possible that there are lifestyle factors not accounted for in the analysis, the researchers point out that they did find a “dose” relationship. That is, the more often subjects ate nuts, the lower the death risk. For example, eating nuts only once a week was linked to a 7 percent lower risk of mortality in both men and women, but eating nuts once or more each day was associated wth a 20 percent lower death risk. While this doesn’t prove that nuts keep people alive longer, the trend suggests that eating nuts more often correlates with better longevity.
What Makes Nuts So Healthy?
Nuts are a great source of healthy unsaturated fat, longevity-boosting dietary fiber, protein, and vitamins and minerals, including antioxidants—all of which are associated with less disease. Nuts are featured in the FDA’sMyPlate food guidelines in the same protein category as meat and beans.
Some people worry they will gain weight if they eat nuts, but surprisingly, the body weight of people who regularly eat nuts has not been shown to be higher than that of non-nut eaters, according to a 2008 article inThe Journal of Nutrition. This is true despite the fact that calories consumed by regular nut eaters total an average of 250 more calories per day than that of people who don’t eat any nuts.
Bottom line: There’s strong evidence that eating nuts regularly can boost your health and your longevity. These surveys did not distinguish between roasted or raw, or salted or unsalted nuts. Consuming too much salt is linked to higher blood pressure, however, so best to choose unsalted or low-sodium nuts when possible.