Should I keep protein low to live longer?

Gil CarvalhoMD, PhD · nutrition and aging researcher, creator of Nutrition Made Simple!

No. There is no compelling human evidence that protein itself is damaging.

What it rests onHe says the kidney-damage theory has mainly been debunked, that a recent paper linking protein to heart disease turned out to be largely mouse work, and that where protein tracks with worse outcomes he suspects the source rather than the protein is doing the work. He names Longo as the disagreement and states it as unresolved: 'So we might just disagree. I don't know. I'm open to arguments and evidence. I might be wrong.'

Valter LongoPhD · biogerontologist, Professor of Gerontology, USC

Yes, through midlife. Keep protein low but adequate, then raise it after 65.

What it rests onProtein intake drives growth-hormone and IGF-1 signalling, and keeping intake near 0.31 to 0.36 g per pound through midlife lowers the risk of the diseases that signalling promotes. He treats the RDA figure as a target rather than a floor, and reverses the advice after roughly 65 on the grounds that the mortality association inverts in the older group.