A new study has found that while substituting proteins for carbohydrates in diets has salutary effects, not all proteins are created equal. Proteins from plant sources were associated to a lower risk of death, while a diet rich in animal source protein, especially red meats, was associated to higher mortality rate.
The article about the study, appearing in JAMA Internal Medicine, begins by asserting a troubling dilemma for eaters: “Defining what represents a macronutritionally balanced diet remains an open question and a high priority in nutrition research.” The study sought to differentiate between different protein sources and determine a link between those sources and mortality. It considered 131,342 participants. The animal protein risk was greater for participants who already had other risk factors like smoking or obesity. Results of the study showed that “After adjusting for major lifestyle and dietary risk factors, animal protein intake was weakly associated with higher mortality.” In ‘Conclusions and Relevance’, the authors write:
“High animal protein intake was positively associated with mortality and high plant protein intake was inversely associated with mortality, especially among individuals with at least 1 lifestyle risk factor. Substitution of plant protein for animal protein, especially that from processed red meat, was associated with lower mortality, suggesting the importance of protein source.”
