Low-Protein, Methionine-Rich Diet May Reverse Aging Effects in Mice

A new study published in Cell Metabolism suggests that a low-protein diet enriched with methionine could improve health in ageing organisms. The research, led by teams from the USC Leonard Davis School of Gerontology, University of Toronto, and Harvard University, challenges current views on metabolic regulation. The findings may offer new therapeutic approaches for metabolic syndrome and age-related conditions. The study tested a diet inspired by Mediterranean eating patterns on 20-month-old mice. These mice consumed the same calories as control groups but lost fat mass without losing lean body mass. Their health improved significantly, with prolonged healthspan, better mobility, less fat build-up, and reduced frailty.

Mice on the low-protein, methionine-supplemented diet (LDMM) showed higher levels of key hormones. Growth hormone, GLP-1, and FGF21 all increased, suggesting a link between amino acid balance and metabolic control. The results indicate that methionine levels, rather than calorie restriction alone, may play a critical role in weight and metabolic regulation.

Human data also supported these findings. Analysis of dietary patterns revealed that high animal protein intake, which raises methionine levels, was associated with higher obesity and Type 2 diabetes risk. In contrast, plant-focused diets correlated with a lower incidence of metabolic diseases. The research invites a rethink of how metabolic hormones and signalling pathways could be targeted for therapy. The team now plans human clinical trials to test the LDMM diet’s safety and effectiveness in diverse populations. If successful, the diet could provide a new strategy for managing metabolic disorders and age-related conditions.