People who ate a daily handful of nuts were 20% less likely to die from any cause over a 30-year period than those who didn’t, according to the largest study of its kind by scientists from the Dana-Farber Cancer Institute, Bringham & Women’s Hospital and the Harvard School of Public Health.
The report, published in the New England Journal of Medicine last week, also showed that those who ate nuts daily also weighed less.
“I think the results are very exciting,” said Peter Pribis, assistant professor of nutrition and dietetics at the University of New Mexico, applauding the “extensive adjustments” made by the researchers during the study in order to best represent a long-term diet and minimize individual variations.
“The message is getting slowly through that nuts are very healthy and something we should eat in small amounts every day. And it’s very easy to do. We talk about exercise, and it can be hard for a lot of people to commit to doing it. But eating nuts takes a few seconds. And look at the huge benefits this group of food can do for us health wise.”
For the study, the researchers analyzed nut consumption with total and cause-specific mortality among 76,464 women in the Nurses' Health Study and 42,498 men in the Health Professionals Follow-up Study. Consumption of a handful of nuts—which included both groundnuts such as peanuts and tree nuts including almonds, Brazil nuts, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts—was inversely associated with total mortality in both men and women, independent of other predictors for death.
In this case, a “handful” translated to 1 ounce or three tablespoons, seven or more times per week. This shouldn't be hard to achieve, according to the NPD Group, which recently found that 77% of U.S. households have nuts or seeds on-hand and 19% of individuals eat nuts at least once in a two-week period.
In addition, the study found that there were significant inverse associations for deaths due to cancer (11% reduction), heart disease (29% reduction) and respiratory disease. And those who regularly ate nuts also tended to have a healthy lifestyle, such as smoking less and exercising more.
Nuts contain an optimal lipid profile, but portion size is important
“One truth is that all nuts contain a very optimal lipid profile,” Dr. Pribis noted. “They have done careful studies to examine the weight issue. Looking at the Nurse’s Health Study, when we age, we tend to gain weight. Those people who ate nuts tended to gain less.”
Indeed, Jenny Heap, MS, RD, manager of global health and nutrition communications at the Almond Board of California, said that the study “adds to the strong body of evidence showing that eating tree nuts regularly is part of a healthy lifestyle.” She also pointed to recent research published in the European Journal of Clinical Nutrition, which showed that participants eating 1.5 ounces of dry-roasted, lightly salted almonds every day experienced reduced hunger and improved dietary vitamin E and monounsaturated fat intake without increasing body weight.
But portion size is key, said Dr. Pribis. “Nuts are very energy dense, so they can curb hunger. But also in realizing that they’re so energy dense, if you exceed two servings per day, then you might start to gain weight. It’s about balance.”
This could also have implications as food manufacturers may look to incorporate more nuts into formulations on the heels of such strong positive results.
“It definitely has implications for food manufacturers,” Dr. Pribis noted. “I am afraid we’ll see some of them take junk food and add nuts to it and try to sell it like it’s ‘healthier’. On the other hand, maybe we’ll see more items like cereal with nuts incorporated. But again, consumers would need to eat less of it to get the benefits”—a variable that could prove difficult for manufacturers to control.
Source: New England Journal of Medicine
“Association of Nut Consumption with Total and Cause-Specific Mortality”
Authors: Ying Bao, M.D., Sc.D., Jiali Han, Ph.D., Frank B. Hu, M.D., Ph.D., Edward L. Giovannucci, M.D., Sc.D., Meir J. Stampfer, M.D., Dr.P.H., Walter C. Willett, M.D., Dr.P.H., and Charles S. Fuchs, M.D., M.P.H.