Quantitative mapping of human hair graying and reversal in relation to life stress.

 eLife 2021; 10: e67437 Doi: 10.7554 / eLife.67437

Commentary

This study investigates the mechanism of gray hair in human hair. Gray hair is generally irreversible and is thought to be related to psychological stress. Here, we developed an approach to profile hair pigmentation patterns (HPPs) along individual human hair trunks to generate quantifiable physical timescales of rapid graying transitions.

The results showed white/gray hair naturally regaining pigmentation across gender, ethnicity, age, and body parts, thereby quantitatively defining the reversibility of gray in humans. Molecularly, gray hair upregulates proteins associated with energy metabolism, mitochondria, and antioxidant defenses; combining HPP profiling and single hair proteomics, we also report hair graying and reversal, which may occur in parallel with psychological stressors, and these observations To generalize the results, we are developing computational simulations, they say. This suggests a threshold-based mechanism for the temporal reversibility of graying.

Overall, they say that this new method of quantitatively mapping the recent life history of HPPs provides an opportunity to examine the longitudinal effects of recent life exposures on human biology.