Differences in Hair Ageing Around the World by L’Oréal Research

Hair greying: ethnic and geographical differences

Seventy-four percent of people between the ages of 45 and 65 have grey hair,
with an average intensity of 27%. Within this age group, men have more grey hairs than women. The age at which hair begins to turn grey and the increase in grey hair with age appear to be clearly linked to ethnic and geographical origin. At a similar age, subjects of Asian or African descent, who have the darkest hair, have fewer grey hairs than those of Caucasian origin, who have lighter hair tones. While men have on average significantly more grey hairs than women of the same age, their hair begins to go grey at the temples, whereas women’s grey hairs are more spread out [1].

The Eumelanin content of hair of different ethnic origins changes with age

Eumelanin content [2] is significantly higher in African American hair, followed by Asian and then Caucasian hair. French eumelanic hair in this study was found to be lighter than Asian and African American hair. The lighter colour is due to lower melanin content. Read more…

The hair

The hair shaft is a fibre made up of three concentric layers.
Starting from the inside and working outwards, these are:
The medulla or marrow, which is made up of nucleus-free cells and is not present in every hair;
The cortex, which is made up of pigment-containing epithelial cells and forms 80 % of the hair shaft ;
The cuticle, an external layer made up of flat cells overlaying each other like tiles on a roof,
known as scales.