Did you know ?

Your hair can still betray you!

Health, strength and stress are revealed in the state of your hair. It is something of a chemicals factory, made up of carbon, oxygen, nitrogen, hydrogen, sulphur, water and minerals, and can give away the details of your DNA and the substances you absorbed several months ago.

Analysing the chemical properties of hair sometimes helps to solve mysteries. This is how we know that Napoleon could have died of arsenic poisoning, Beethoven of lead poisoning and Ramses II, a natural Titian red, dyed his hair to bring out the redness!

Hair in numbers

• 100,000 to 150,000 is the number of hairs on a normal head, varying according to whether they are dark or fair. There are more if you are fair because they are finer.
  
  
• Growing in tufts of 1 to 5 hairs, their lifecycle ranges from 2 to 6 years. The active growth period lasts from 3 to 5 years, followed by an interval of 3 to 4 weeks and a rest period of 3 to 4 months before they fall out and are replaced by new hair.
  
  
• You lose 50 to 100 hairs every day.
  
  
• Hair grows 15 to 20 cm a year, so the average person produces 30 to 40 metres of hair a day. The total length of the average 130,000 hairs on a head measures 13 kilometres!
  
  

Why does hair turn white?

Hair gradually loses its natural pigmentation; the melanocytes, the cells which produce melanin, slow down their output.

White hairs tend to make their first appearance between the ages of 34 and 42, although there is no hard and fast rule about this; some hair turns white much earlier for a range of reasons including migraines, neuralgia, heavy medication, depression or just plain genes.

(Source : L'art de la couleur - L'Oréal Professionnel - Coiffure de Paris)

The hair strength

A hair is as fine as a strand of a spider's web, as strong as a silk thread (hair in good health can support a weight of over 10 tonnes!), as elastic as a liana, as absorbent as a sponge, malleable as plasticine, long-lasting as eternity (Egyptian mummies have been found with their hair intact)!