A high intake of proteins from animal sources such as red meats, eggs and dairy may increase mortality rate, while high consumption of proteins from plant sources like bread and nuts could lower the risk of death, a large new study has claimed.
However, increased death risk primarily associated with red meats, eggs and dairy may not be found among those with healthy lifestyle, researchers said.
"Overall, our findings support the importance of the sources of dietary protein for long-term health outcomes," said Mingyang Song from Massachusetts General Hospital in the US.
"While previous studies have primarily focused on the overall amount of protein intake - which is important - from a broad dietary perspective, the particular foods that people consume to get protein are equally important," said Song.
The findings have public health implications and can help refine current dietary recommendations about protein intake, in light of the fact that it is not only the amount of protein but the specific food sources that is critical for long-term health.
In the largest study to examine the effects of different sources of dietary protein, researchers analysed more than 30 years of data of participants, totalling more than 3.5 million person-years.
A high consumption of protein from animal sources - any types of meat, eggs or dairy - was weakly associated with an increased rate of death, while high consumption of protein from plant sources - breads, cereals, pasta, beans, nuts and legumes - was linked with a lower mortality rate, researchers said.
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, they said.
"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," said Song.
The findings were published in the journal JAMA Internal Medicine.
