Go nuts to reduce heart attack risk, study says

By Jasminee Sahoye

A recent study suggests that a simple way to lower the risk of dying from a heart attack is to eat nuts.

Researchers at Vanderbilt University and the Shanghai Cancer Institute found that peanut and nut consumption was associated with fewer deaths among low-income and racially diverse populations, especially from heart disease.

“Nuts are rich in nutrients, such as unsaturated fatty acids, fiber, vitamins, phenolic antioxidants, arginine and other phytochemicals. All of them are known to be beneficial to cardiovascular health, probably through their anti-oxidative, anti-inflammatory and endothelial function maintenance properties,” said senior author Xiao-Ou Shu, M.D., Ph.D., associate director for Global Health at the Vanderbilt-Ingram Cancer Centre (VICC) and professor of medicine in the Department of Epidemiology.

While research has previously linked nut consumption with lower mortality, those studies focused mainly on higher-income, white populations. This study was the first to discover that all races – Blacks, whites and Asians alike – could potentially increase heart health by eating nuts and peanuts.

“In our study, we found that peanut consumption was associated with reduced total mortality and cardiovascular disease mortality in a predominantly low-income Black and white population in the U.S., and among Chinese men and women living in Shanghai,” Shu said.

This study was based on three large ongoing cohort studies. Participants included more than 70,000 Americans of African and European descent from the Southern Community Cohort Study (SCCS), who were mostly low-income, and more than 130,000 Chinese from the Shanghai Women’s Health Study (SWHS) and the Shanghai Men’s Health Study (SMHS).

For participants in the SCCS, deaths were determined by linking with the National Death Index and Social Security Administration mortality files, and for participants in the SWHS / SMHS, by linking with the Shanghai Vital Statistics Registry and by conducting home visits.

In total, more than 14,000 deaths were identified, with a median follow-up of 5.4 years in the SCCS, 6.5 years in the SMHS, and 12.2 years in the SWHS.

Peanut consumption was associated with decreased total mortality, particularly cardiovascular mortality across all three racial / ethnic groups, among both men and women and among individuals from low-SES groups. Because peanuts are much less expensive than tree nuts, as well as more widely available to people of all races and all socioeconomic backgrounds, increasing peanut consumption may provide a potentially cost-efficient approach to improving cardiovascular health, Shu said.

“The data arise from observational epidemiologic studies, and not randomized clinical trials and thus we cannot be sure that peanuts per se were responsible for the reduced mortality observed,” said William Blot, Ph.D., associate director for Cancer Prevention, Control and Population-based Research at VICC and a co-author of the study.

He did note that “the findings from this new study, however, reinforce earlier research suggesting health benefits from eating nuts, and thus are quite encouraging.”

The American Heart Association recommends eating four servings of unsalted, unoiled nuts a week. However, nutrient-rich nuts are also high in calories, so don’t eat too many if you’re watching your weight. A serving size is a small handful or 1.5 ounces of whole nuts or two tablespoons of nut butter.

Another study on peanuts says women need not fear that eating peanuts during pregnancy could cause their child to develop a peanut allergy.

“Our study showed increased peanut consumption by pregnant mothers who weren’t nut allergic was associated with lower risk of peanut allergy in their offspring,” says the study’s senior author Michael Young, MD, of Boston Children’s Division of Allergy and Immunology. “Assuming she isn’t allergic to peanuts, there’s no reason for a woman to avoid peanuts during pregnancy.”