In 2017, Professor David Sinclair and his team identified a critical step in the molecular process that facilitates the repair of DNA damage . We experience DNA damage on a daily basis from sunlight and other environmental sources.
DNA damage is thought to contribute to the rising risk of cancer as we age and is implicated in various age-related diseases. Our cells have the innate ability to repair that damage, but, unfortunately, that ability to repair declines as we grow older.
In a 2017 study, the researchers identified that the metabolite NAD+, which occurs naturally in every single cell in our body, has a critical role in DNA repair by regulating the protein-to-protein interactions involved in that process.
They found that treating mice with the NAD+ precursor known as NMN boosted the cells’ ability to repair DNA damage caused by aging or radiation exposure.
“The cells of the old mice were indistinguishable from the young mice after just one week of treatment,” said lead author Professor David Sinclair of UNSW School of Medical Sciences and Harvard Medical School Boston.
As well as boosting DNA repair, it has also been established that NAD+ activates all seven of the sirtuins, which are genes associated with longevity and health.
NMN is currently in human clinical trials at Brigham and Women’s Hospital.
Not related to the Sinclair lab but worth noting is that a small trial of NMN was concluded by researchers in Japan which at the dosage used, concluded that it was generally safe and well tolerated . While the study showed no benefit from taking NMN, the dosage was very low and it was not the purpose of this phase 1 study.
 Li, J., Bonkowski, M. S., Moniot, S., Zhang, D., Hubbard, B. P., Ling, A. J., … & Aravind, L. (2017). A conserved NAD+ binding pocket that regulates protein-protein interactions during aging. Science, 355(6331), 1312-1317.
 Irie, J., Inagaki, E., Fujita, M., Nakaya, H., Mitsuishi, M., Yamaguchi, S., … & Okano, H. (2019). Effect of oral administration of nicotinamide mononucleotide on clinical parameters and nicotinamide metabolite levels in healthy Japanese men. Endocrine journal, EJ19-0313.