Hmmm .... this is no old white-haired man speaking... but
looking at all the posts, the conclusion is that there is no
specific age by which one's hairs start to turn white. However, it
is correct to say that you will have less black hairs as you grow
older. Plus you will loose more hairs!
However, for sure: stress, sickness, lack of sleep, worry, poor
diet and lost of love can cause white hairs.