HMM: Treatment with a simple chemical restores DNA repair to aging mice.

A recent paper published in Science shows that a chemical used in the DNA repair process, nicotinamide adenine dinucleotide (NAD+), has a concentration that declines with age. This decline may drive the age-associated accumulation of DNA damage—a finding that suggests supplementing NAD+ might offset some of the effects of aging.

The team behind the paper used human embryonic kidney cells (which grow well in the lab) to look at the role of this chemical. The authors found that NAD+ binds to the protein “deleted in breast cancer 1” (DBC1), which—as its name implies—was previously implicated in cancer. DBC1 normally binds to and inhibits another protein that performs DNA repair. But NAD+ blocks this interaction, releasing the inhibition on DNA repair.

Therefore, as NAD+ concentrations decline with age, it’s possible there is insufficient NAD+ to bind to the DBC1 protein, leaving it free to block DNA repair.

To test this proposed mechanism in a living organism, the authors used aging mice. As expected, NAD+ concentrations declined as the mice aged. With its decline, DBC1 was increasingly binding to and shutting down the DNA repair enzyme. The authors then gave the mice the chemical precursor to NAD+, which should restore their NAD+ concentrations. Once the mice were given this treatment, their DNA repair activity increased, and the levels of DNA damage were reduced.

I take Niagen, which contains nicotinamide riboside, a precursor to NAD+. Does it help? Ask me in 20 years.