It has been observed that identical twins can sometimes show different rates of hair loss. Since they are genetically identical it has been proposed that the difference is due to different lifestyle factors.
In one study of twins, it was found that men who did not wear hats or use other head protection when outdoors experienced significantly greater hair loss.
There is a good physiological basis to support the idea that ultraviolet radiation from the sun is harmful to human hair. Other studies using human hair models, have demonstrated oxidative damage to mitochondrial DNA and follicular apoptosis in response to 20J of ultraviolet radiation.
All of this makes it reasonable to recommend measures to protect the head from the sun’s rays when outside for more than a short time. Such measures could be the use of a cap or hat, or the use of sun cream.
In my next article I’ll be discussing whether it is true that smoking and alcohol can be harmful for your hair, so keep a look out in your inbox.
Dr Peter Griffiths