Aging Biology

The article distinguishes chronological age from biological or biochemical age. NMN is presented as an NAD precursor, but the article warns that many commercial NMN products may degrade quickly. Aging is described as biological deterioration involving epigenetic drift, DNA damage, NAD decline, mitochondrial dysfunction, inflammation, immune imbalance, hormonal decline, and reduced repair capacity. The genome is presented as relatively constant, while the epigenome determines which genes are active or inactive. Sirtuins are described as regulators of the epigenome and DNA repair. The article links age-related NAD decline to weakened maintenance of youthful gene expression and cellular function.