Dietary intake of animal and plant proteins and risk of all cause and cause-specific mortality: The Epic-Italy cohort

Abstract

BACKGROUND: To examine the associations of animal and plant protein intake with all-cause, cardiovascular and cancer mortality risk in middle-aged Italian men and women with substantially lower animal protein intake than North Americans. METHODS AND RESULTS: Food consumption was assessed by validated Epic semiquantitative FFQs. Multivariable Cox models stratified by center, age, and sex, and adjusted for confounders, estimated associations of animal and plant protein consumption with mortality for all causes, cardiovascular disease, and cancer. After a median follow-up of 15.2 years, 2,449 deaths were identified in 45,009 participants. No significant association between intake of total, animal or plant protein and mortality was found in the fully adjusted models. Substitution of plant protein for animal protein was inversely associated with cardiovascular mortality (HR, 0.47; 95% CI, 0.24–0.92) only in people with at least 1 unhealthy lifestyle risk factor and poor adherence to a Mediterranean diet. Participants in the highest quintile group of animal protein intake had higher glucose, total and LDL cholesterol levels than those in the lowest quintile. In contrast, higher plant protein intake was negatively associated with fasting insulin and cholesterol, despite higher BMI, physical inactivity and starch consumption. CONCLUSIONS: Replacing plant protein for animal protein was associated with lower cardiovascular mortality among individuals with unhealthy lifestyle risk factors. High animal but not plant protein intake is associated with impaired fasting glucose and hypercholesterolemia, despite lower calorie and carbohydrate intake, suggesting that protein source plays crucial roles in modulating cardiometabolic health independently of body weight.