Characteristic Features of Japanese Women's Hair With Aging and Hair Loss

The study investigated hair loss in Japanese women, involving 46 women with hair loss and 113 women with no or less hair loss, aged 14-68 years. It was found that hair loss in Japanese women typically began after the age of 40 and presented as a diffuse central pattern. Key findings included a decline in hair density, anagen hair ratio, and growth rate after the 40s, with a peak in mean hair diameter and the ratio of thick hairs around the age of 40, followed by a decrease associated with hair loss. The study also noted that hair loss in Japanese women was characterized by a reduction in multi-haired follicular units and an increase in one-haired units, rather than an increase in vellus-like hairs. Additionally, the study reported that hair growth rate and mean hair diameter in Japanese women were slightly lower than in Caucasian women, and that female pattern hair loss (FPHL) was less common in Japanese women, with a higher prevalence in those in their 60s. The study concluded that the major factors contributing to FPHL in Japanese women were a decrease in hair density and thick hair ratio.