Calorie restriction extends life and improves health in nearly every species tested to date. Sensing of levels of methionine, an essential amino acid, appears to be one of the controlling mechanisms involved in the shift of metabolism into a state that ensures greater longevity. Reduction in dietary methionine without reducing calories has been show to extend life in rats and mice, for example. Here researchers demonstrate that it can do so in yeast as well:
It is established that glucose restriction extends yeast chronological and replicative lifespan, but little is known about the influence of amino acids on yeast lifespan, although some amino acids were reported to delay aging in rodents. Here we show that amino acid composition greatly alters yeast chronological lifespan. We found that non-essential amino acids (to yeast) methionine and glutamic acid had the most significant impact on yeast chronological lifespan extension, restriction of methionine and/or increase of glutamic acid led to longevity that was not the result of low acetic acid production and acidification in aging media.
Remarkably, low methionine, high glutamic acid and glucose restriction additively and independently extended yeast lifespan, which could not be further extended by buffering the medium (pH 6.0). Our preliminary findings using yeasts with gene deletion demonstrate that glutamic acid addition, methionine and glucose restriction prompt yeast longevity through distinct mechanisms.