However, well before the hair goes grey, the hair with pigment already begins to change.
There are two main changes to pigmented hair as we age
1. Hair thickness.
2. Hair growth rate.
In one study, they classed women into three groups
- Young - Average age - 19 years old (range 15-21)
- Menopausal - Average age - 43 years old (range 38-48)
- Post Menopausal - Average age - 61 years old (range 50-65)
|Hair Growth Rate (inches/yr)||6.2||5.9||5.2|
|Hair Thickness* (μm)||74||69||59|
Therefore the reason why hair may appear to thin down as we age is in part because it is growing slower and the strand size is decreasing.
* Hair thickness was taken as average diameter (remember hair is slightly elliptical)
Image Credit : No attribution given by websites - gorgeous hair though!