Anti-aging supplement effects in humans

Metabolism Synthesis of nicotinamide adenine dinucleotide (NAD+) decreases during aging, which is thought to limit the activity of enzymes that require it for their catalytic activity. Studies in animals indicate that replenishment of cellular NAD+ can have beneficial effects on aging and age-related diseases, but the situation in humans is less clear. Yoshino et al. report the effects of supplementation with the NAD+ precursor nicotinamide mononucleotide in overweight or obese postmenopausal women with prediabetes (see the Perspective by Hepler and Bass). The treatment improved insulin sensitivity in muscle, although a change in NAD+ content was not detected. The treatment also increased the expression of platelet-derived growth factor b. The results support potential therapeutic action of NAD+ supplementation in humans, but how various NAD+ precursors are processed in specific tissues remains to be fully explored. Science , abe9985, this issue p. [1224][1]; see also abj0764, p. [1147][2] [1]: /lookup/doi/10.1126/science.abe9985 [2]: /lookup/doi/10.1126/science.abj0764