Low-Protein, Methionine-Rich Diet May Slow Aging and Boost Longevity

A new study suggests that a low-protein diet enriched with methionine can extend the healthspan of ageing organisms. The research, published in Cell Metabolism, was led by scientists from USC, the University of Toronto, and Harvard University. It challenges common views on protein by showing the benefits of precise amino acid balance in nutrition. The team tested a longevity diet inspired by Mediterranean eating patterns on 20-month-old mice. Those fed the low-protein, methionine-supplemented diet (LDMM) lived longer and accumulated less fat. Despite eating the same number of calories as other groups, these mice lost fat mass without losing muscle.

Blood tests revealed higher levels of growth hormone, GLP-1, and FGF21 in the LDMM group. These hormonal changes are linked to improved metabolism and longevity. The study also analysed human data, finding that high animal protein intake increased obesity and Type 2 diabetes risk, while plant-focused diets lowered metabolic disease rates.

The findings suggest that not all proteins have the same effect on health. Instead, the precise balance of amino acids, such as methionine, plays a key role in ageing and metabolic health. The researchers now aim to test the LDMM diet in human clinical trials to confirm its safety and effectiveness across diverse populations. The study highlights how tailored nutrition could improve long-term health. Its results may influence dietary guidelines for ageing and metabolic disease prevention.