Abstract P510: Association of Animal and Plant Protein Intake With Mortality Among US Adults: A Prospective Cohort Study

Introduction: Animal protein sources, especially red and processed meat, have been associated with adverse health outcomes. Epidemiological evidence on the isocaloric substitution of plant for animal protein on mortality risk remains limited. Hypothesis: We hypothesized that substituting plant protein for carbohydrates and animal protein would be associated with lower mortality. Method: We included a nationally representative sample of 37 233 US adults ≥20 years with 24-h dietary recall data from eight National Health and Nutrition Examination Survey (NHANES) cycles (1999-2014). Mortality from all causes, heart disease, and cancer were identified through National Death Index linkage (until December 31, 2015). We used Cox proportional hazards regression to estimate the association between plant and animal protein intake and mortality after adjustment for potential confounding factors. Results: During 297 768 person-years of follow-up, 4 866 total deaths occurred, including 849 deaths from heart disease and 1 068 deaths from cancer. After multivariable adjustment, higher intake of total animal protein was not associated with total mortality. Plant protein was associated with lower total mortality; when comparing the lowest with highest quintiles of plant protein intake, the multivariable adjusted HR (95% CIs) of total mortality was 0.73 (0.61, 0.88); P for trend <0.001. The HRs (95% CIs) comparing extreme quintiles were 0.71 (0.48, 1.05) for heart disease mortality, and 0.74 (0.53, 1.04) for cancer mortality. When isocalorically replacing 5% of energy from total animal protein with plant protein, the multivariable HRs were 0.49 (0.32, 0.74) for total mortality, 0.51 (0.28, 0.95) for heart disease mortality, and 0.53 (0.28, 1.00) for cancer mortality. For different food sources of animal protein, isocaloric substitution of 2% of energy from plant protein for protein in unprocessed red meat (0.74, 95% CI: 0.63, 0.87), processed meat (0.68, 95% CI: 0.53, 0.89), total dairy (0.74, 95% CI: 0.58, 0.94), and 1% of energy from plant protein for seafood (0.86, 95% CI: 0.79, 0.93) was each associated with a lower risk of total mortality. Conclusions: Higher plant protein intake was associated with lower total mortality. Isocalorically replacing animal protein with plant protein was associated with lower total mortality.