New research shows that high-protein diets like Atkins and Paleo may be linked to cancer risks.
In the new study published in the Cell Metabolism journal, middle-aged people who ate protein-heavy diets (that is, 20% of daily calories derived from protein) had a markedly increased risk of dying from cancer compared to their low-protein counterparts.
But it’s not all proteins that have the same potentially dangerous effect – animal proteins (meat and dairy) largely produced the risk, as opposed to plant-derived proteins.
On average Americans eat a 16% protein diet, with two-thirds of those proteins coming from animal sources.
“Almost everyone is going to have a cancer cell or pre-cancer cell in them at some point,” says one of the study’s co-authors, Valter Longo, a University of Southern California professor. “The question is: Does it progress? Turns out one of the major factors in determining if it does is protein intake.”
“The majority of Americans are eating about twice as much proteins as they should, and it seems that the best change would be to lower the daily intake of all proteins but especially animal-derived proteins,” said Longo. “But don’t get extreme in cutting out protein; you can go from protected to malnourished very quickly.”