Men need sufficient protein to help maintain muscle mass and strength as they age. A study published online July 13, 2020, by JAMA Internal Medicine suggests the source of that protein also may dictate how long they live. Scientists examined the diets of more than 400,000 people ages 50 and older, who consumed protein from plant sources, red meat, and eggs. They were then followed for more than 16 years. Those who ate mostly plant protein instead of red meat or egg protein had a 13% to 24% lower risk of death from any cause.