Researchers who have analysed more than 30 years of data found that a high consumption of protein from animal sources was associated with an increased rate of death.
Consuming protein from plant sources led to a lower mortality rate. The link between animal protein intake and an elevated mortality risk only applied to participants with at least one factor associated with an unhealthy lifestyle being either obesity, heavy alcohol consumption, a history of smoking or physical inactivity.
In fact, the association disappeared in participants leading a healthy lifestyle. Analysis based on specific sources of protein indicated that the animal-protein-associated mortality risk applied primarily to processed and unprocessed red meats, which include both beef and pork products, and not to protein from fish or poultry.
“Our findings suggest that people should consider eating more plant proteins than animal proteins, and when they do choose among sources of animal protein, fish and chicken are probably better choices. Future studies should examine the mechanisms underlying the different effects of plant and animal proteins – along with different sources of animal proteins – on overall health,” said Mingyang Song, a researcher at the Massachusetts General Hospital and the Harvard T.H. Chan School of Public Health. Song served as lead author of the study which appeared in the August issue of JAMA Internal Medicine, a peer-reviewed journal.
It was the largest study to probe the effects of different sources of dietary protein with researchers looking at previously recorded data on health outcomes and diet for more than 130 000 people in the United States.
People who consumed their protein from plant foods managed to maintain a healthy weight and had a lower risk of chronic diseases such as cardiovascular disease, diabetes and cancers.
“Although we didn’t look at soy in our study because its consumption is very low in the United States, there is evidence supporting that soy may be a good protein source for health,” Song