Experts Reject Protein Restriction for Longevity — SkimNews
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- University of Wisconsin-Madison researchers published a review in Cell Press Blue drawing on 350 prior papers that argued protein restriction promotes metabolic health, healthspan, and lifespan—though much of the cited evidence came from animal studies and the authors acknowledge the effect on human lifespan is unknown.
- Stuart Phillips, a kinesiology professor at McMaster University, dismissed the paper as "a beautiful mouse story, sold as human advice" and said low protein intake is linked to more frailty, falls, and higher mortality in people over 65.
- The 2026 Dietary Guidelines for Americans recommend 1.2 to 1.6 grams of protein per kilogram of body weight—a range most Americans already meet, according to Donald Layman of the University of Illinois, who helped set the guidelines.
- Experts flagged special risks for sedentary individuals and patients on GLP-1 medications, noting these drugs already accelerate muscle loss and suppress appetite, making adequate protein intake critical to preserving lean tissue.
- The PROT-AGE study, initiated by the European Geriatric Medicine Society, recommends 1-1.2 grams of protein per kilogram for older adults with higher intake for those who exercise, per geriatric dietitian Katie Dodd, who warned reducing protein could threaten independence.
- William Evans of UC Berkeley cautioned against confusing maximal lifespan with healthy lifespan, noting that protein synthesis slows with age and that sedentary individuals cutting protein could lose lean tissue faster.
- Phillips noted that researchers studying premature mortality increasingly converge on a "more beans and less bacon" approach—prioritizing protein quality through minimally processed plant and animal foods rather than blanket restriction.
Why it matters: The practical stakes center on older adults: federal guidelines already recommend 1.2-1.6 g/kg, well above the protein levels implied by the review, and aging reduces the body's ability to synthesize protein. Acting on mouse-derived restriction advice could accelerate sarcopenia, falls, and loss of independence in the exact population most interested in healthy aging.
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