Low-Protein, Methionine-Rich Diet May Slow Aging in Mice—Human Trials Next

A new study suggests that a low-protein diet enriched with methionine can improve the health of aging organisms. The research, published in Cell Metabolism, was carried out by scientists from USC, the University of Toronto, and Harvard University. The team tested four dietary regimens on 20-month-old mice. One group received a novel low-protein, methionine-supplemented longevity diet (LDMM). This diet draws inspiration from traditional Mediterranean eating patterns, focusing on plant-based foods with precise methionine supplementation.

Mice on the LDMM diet showed clear health benefits. They maintained prolonged healthspan, better mobility, and increased strength. Fat accumulation and frailty were also reduced, despite consuming the same number of calories as other groups. These mice lost fat mass without losing lean body mass.

Blood tests revealed elevated levels of growth hormone, GLP-1, and FGF21 in the LDMM group. These hormonal changes contributed to improved metabolic health. The study also analysed human data, finding that high animal protein intake was linked to higher obesity and Type 2 diabetes risk. In contrast, plant-focused diets with moderated amino acid intake reduced metabolic disease rates.

The researchers highlighted the need for molecular precision in nutrition. They argued that protein cannot simply be labelled as 'good' or 'bad' without considering its composition and context. The team now plans to test the LDMM diet in human clinical trials to assess its safety and effectiveness across diverse populations. The findings point to potential dietary strategies for extending healthspan in aging populations. The LDMM diet improved metabolic markers and physical function in mice without calorie restriction. Human trials will determine whether similar benefits can be achieved in people.