In a Review, Mitchell Lee and colleagues attempt to separate fact from fiction for so-called "anti-aging" dietary interventions. They also explore these diets' potential shared mechanisms of action. For almost a century, caloric restriction and other dietary interventions have been known to extend life span and delay age-associated disease – at least in laboratory animals – but just how these interventions work remains unclear.

What's more, despite the recent popularization of some of these diets, such as ketogenic diets and intermittent fasting, the efficacy and safety of these diets for humans has yet to be established outside of a laboratory setting. Here, Lee et al. summarize the current literature concerning the most studied anti-aging dietary interventions – those that appear to delay or reverse the hallmark molecular mechanisms of aging. While these interventions are well studied in model organisms, like mice, flies and yeast, it is not currently possible to know whether similar diets affect biological aging in people, according to the authors.

Research to date shows that the physiological consequences of these dietary interventions are complex, even in the simplest model organisms; it has also revealed intriguing similarities across anti-aging diets. According to Lee et al., a common mechanism for anti-aging diets may be related to the inhibition of the protein kinase mTOR. This evolutionarily conserved signaling pathway may provide a molecular target for drugs that could prove useful for increasing health longevity in humans.

"Future research should focus on both better understanding the cellular and molecular mediators of anti-aging diets under highly controlled laboratory conditions as well as the impact of genetic and environmental variation on health outcomes associated with these diets," write Lee et al.