Association of Nut Consumption with Total and Cause-Specific Mortality

Gabrielle ShererCardiovascular Risk Reduction

Jeff Luckring MS, RD

Bao Y, Han J, Hu F, et al. Association of Nut

Consumption with Total and Cause-Specific Mortality. N Engl J Med. 2013; 369:2001-2011

Citation

Nuts! Unsaturated fatty acids Fiber Vitamins Minerals Antioxidants Sterols

Background

Background

Reductions in: Blood cholesterol Oxidative stress Inflammation Visceral adiposity Hyperglycemia Insulin resistance Endothelial

dysfunction

Reduced risks of: CHD DM2 Metabolic syndrome Colon cancer HTN Gallstone disease Diverticulitis Death from

inflammatory diseases

Unknown: relationship btw nut consumption and

total mortality

Examine the association of nut consumption with total and cause specific mortality in two large, independent cohort studies of nurses and other health professionals.

Objective

Prospective cohort study Repeated measures of diet

separate data on peanuts and tree nuts Adj confounding variables 30 years of f/u data on 27,000+ deaths

Design

Nurses’ Health Study

121,700 female nurses n= 76,464 from 11 U.S. states enrolled in 1976

Health Professionals Follow-up Study 51,529 male health professionals n= 42,498 from all 50 states enrolled in 1986

Exclusion: h/o Cancer, CHD, CVA, DM, smoking 40<BMI<18.5

Participants & Setting

F/U questionnaire every other yr Baseline: year of first validated food frequency

questionnaire How often was a 1 oz serving of nuts consumed?

Subsequent questionnaires split reporting of nut consumption into peanuts and other nuts.

Systematic searches of vital records of states and National Death Index

Blinded Physician-COD using International Classification of Diseases

Methods

Primary Endpoint: death from any cause Nut consumption :

never or almost never one to three times a month once a week two to four times a week five or six times a week once a day two or three times a day four to six times a day more than six times a day

Outcome Measures

Cumulative average of nut consumption Suspended updating of dietary variables when

participants reported dx of CVA, CHD, angina, DM, or cancer

Cox proportional-hazards models adj for predictors of death hazard ratios and 95% confidence intervals

Wald test P values for trend

Restricted-cubic-spline regression model the association

Controlled for intake of Na and oil

Statistical Analysis

More frequent nut consumption- leaner, less

likely to smoke, more likely to exercise, more likely to use multivit/min, ate more fruit/veg, drank more etoh

Significant inverse association btw frequency of nut consumption and total mortality among women and men

Results

Consume nuts 7+ times per week – 20% lower

death rate Consistent with smaller studies Strengths: large sample, repeated measures

of intake over 30yrs, measures to min confounding factors and reverse causality

Limitations: self reporting of intake (avg), nut preparation not considered, cohort of health professionals (metabolic processes unlikely to differ from gen pop).

Conclusions

Recommend nut consumption

2-4 x per week Replace foods high in sat fat Focus on portion size -1 oz (1/4 cup) Consider preparation

Implications for Clinical Practice