Nuts, Peanuts Linked to Reduced Death Rates

Regular consumption of peanuts or nuts every day may help protect against conditions such as cancer and heart disease, new research from Maastricht University has shown. No protective effect for peanut butter, however, was found.

Both men and women who ate a minimum of 10 grams nuts or peanuts a day showed a lower risk of dying from several major causes of death than people who don’t consume nuts or peanuts. Mortality reduction was highest in respiratory disease, neurodegenerative disease, and diabetes, followed by cancer and cardiovascular diseases.

The study was conducted as part of the Netherlands Cohort Study, which has been running since 1986 among over 120,000 Dutch 55-69 year old men and women.

Consumption of nuts was assessed by asking about portion size and frequency of intake of peanuts, other nuts (tree nuts), and peanut butter. The researchers analyzed the relationship with overall and cause-specific mortality since 1986.

Professor Piet van den Brandt, project lead and epidemiologist, commented:

“It was remarkable that substantially lower mortality was already observed at consumption levels of 15 grams of nuts or peanuts on average per day (half a handful). A higher intake was not associated with further reduction in mortality risk. This was also supported by a meta-analysis of previously published studies together with the Netherlands Cohort Study, in which cancer and respiratory mortality showed this same dose-response pattern.”

The link between nut/peanut intake and cardiovascular death substantiate earlier results from American and Asian studies that were often focused on cardiovascular diseases. In this new study, however, it was found that mortality due to respiratory, diabetes, cancer, and neurodegenerative diseases was also lowered among users of peanuts and nuts.

Both peanuts and tree nuts contain compounds such as monounsaturated and polyunsaturated fatty acids, various vitamins, fiber, antioxidants, and other bioactive compounds, that potentially contribute to the lower death rates.

Unlike peanuts, no association was actually found between peanut butter intake and mortality risk. In addition to peanuts, commercial peanut butter contains added components like salt and vegetable oils.

It has previosuly been shown that peanut butter contains trans fatty acids and therefore the composition of peanut butter is different from peanuts. The adverse health effects of salt and trans fatty acids may inhibit any protective effects of peanuts.

Piet A van den Brandt and Leo J Schouten
Relationship of tree nut, peanut and peanut butter intake with total and cause-specific mortality: a cohort study and meta-analysis
Int. J. Epidemiol. first published online June 11, 2015 doi:10.1093/ije/dyv039

Abstract:

“Background: Nut intake has been associated with lower mortality, but few studies have investigated causes of death other than cardiovascular disease, and dose-response relationships remain unclear.

Methods: We investigated the relationship of nut (tree nut, peanut) and peanut butter intake with overall and cause-specific mortality. In the Netherlands Cohort Study, 120 852 men and women aged 55–69 years provided information on dietary and lifestyle habits in 1986. Mortality follow-up until 1996 consisted of linkage to Statistics Netherlands. Multivariate case-cohort analyses were based on 8823 deaths and 3202 subcohort members with complete data on nuts and potential confounders. We also conducted meta-analyses of our results with those published from other cohort studies.

Results: Total nut intake was related to lower overall and cause-specific mortality (cancer, diabetes, cardiovascular, respiratory, neurodegenerative diseases, other causes) in men and women. When comparing those consuming 0.1−<5, 5−

Conclusions: Nut intake was related to lower overall and cause-specific mortality, with evidence for nonlinear dose-response relationships. Peanut butter was not related to mortality.”