Eating nuts and peanuts associated with reduced overall, cardiovascular death

Eating nuts and peanuts was associated with a reduced risk of overall death and death from cardiovascular disease across different ethnic groups and among individuals with low socioeconomic status, which suggests that peanuts, because of their affordability, may be a cost-effective measure to improve cardiovascular health, according to an article published online by JAMA Internal Medicine.

Nuts are rich in nutrients and peanuts, although classified as legumes, have nutrients similar to tree nuts. Peanuts are included as nuts in many epidemiologic studies. Evidence suggests that nuts may be beneficial with respect to coronary heart disease, according to the study background.

Xiao-Ou Shu, M.D., Ph.D., of the Vanderbilt University School of Medicine, Nashville, and coauthors sought to examine the association between nut/peanut consumption and mortality.

The authors analyzed three large study groups involving 71,764 low-income black and white men and women living in the southeastern United States and 134,265 Chinese men and women living in Shanghai, China. Men in both the U.S. and Chinese study participant groups consumed more peanuts than women. In the U.S. group, about 50 percent of the nut/peanut consumption was peanuts and in the participant groups from China only peanut consumption was assessed.

Study results indicate that nut intake was associated with reduced risk of total mortality and cardiovascular disease (CVD) death in all three groups. In the U.S. study participant group, there was a reduced risk of total mortality of 21 percent for individuals who ate the most peanuts. In the Chinese study participant groups, the risk reduction for death associated with high nut intake was 17 percent in a combined analysis. An association between high nut intake and reduced risk of ischemic heart disease was seen for all the ethnic groups.

"We found consistent evidence that high nut/peanut consumption was associated with a reduced risk of total mortality and CVD mortality. This inverse association was observed among both men and women and across each racial/ethnic group and was independent of metabolic conditions, smoking, alcohol consumption and BMI. We observed no significant associations between nut/peanut consumption and risk of death due to cancer and diabetes mellitus. ... We cannot, however, make etiologic inferences from these observational data, especially with the lack of a clear dose-response trend in many of the analyses. Nevertheless, the findings highlight a substantive public health impact of nut/peanut consumption in lowering CVD mortality given the affordability of peanuts to individuals from all SES (socioeconomic status) backgrounds," the study concludes.

In a related Editor's Note, Mitchell H. Katz, M.D., director of the Los Angeles County Department of Health Services and a deputy editor of JAMA Internal Medicine, writes: "Of course, peanuts are not really nuts (they are legumes since they grow in bushes, unlike tree nuts), but who cares if they help us to live longer at an affordable price."

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(JAMA Intern Med. Published online March 2, 2015. doi:10.1001/jamainternmed.2014.8347. Available pre-embargo to the media at http://media.jamanetwork.com.)

Editor's Note: This work was supported by grants from the U.S. National Cancer Institute. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Media Advisory: To contact corresponding author Xiao-Ou Shu, M.D., Ph.D., call Craig Boerner at 615-322-4747 or email craig.boerner@vanderbilt.edu. To contact Editor's Note author Mitchell H. Katz, M.D., call 312-464-5262 or email mediarelations@jamanetwork.org.