A Low Methionine Diet: New Data for Cancer Therapy Favors Plant Foods

Amino acids are the building blocks of all proteins in the body. A subcategory of amino acids contain sulfur and includes methionine (Met) and cysteine, which not only make up proteins but also play many roles in metabolism and health. Researchers have been interested in dietary sulfur amino acid restriction since the 1990s, when studies began to show health benefits in animals fed Met-restricted diets. In one early study involving rats, 80 percent Met restriction increased average and maximum lifespans by between 42 and 44 percent. Pictured below is another study in yeast demonstrating extended lifespan with Met restricted diets.

Scientists have long known that animals on calorie-restricted diets live longer and healthier, but they’ve been searching for ways bring about the improvements without asking people to eat less. In a review of studies, sulfur amino acid restriction consistently demonstrated a range of beneficial effects including enhanced lifespan — without calorie restriction. The analysis found that Met restriction has been associated with delayed aging and longer lifespans in human cells, yeast, and animals including fruit flies and rodents. Animals fed sulfur amino acid-restricted diets also had health improvements including reductions insulin sensitivity; and more efficient fuel-burning. But can a Met restricted…