This theory suggests that a fatal cocktail of excess oils, air pollutants, sebum, and dead cells can become lodged around a hair shaft and render it incapable of growth. The first question then is, Why does the hair on the other areas of the head, particularly the sides and back, continue to flourish? Some have tried to explain that because the hairs grow in a downward direction, this causes the accumulation of dirt to slide down the hairs away from the shaft and follicle, therefore protecting the hair. But this is simply not true.
This theory that hair loss can be caused by having a dirty scalp fails to account for not only the vast numbers of clean yet bald men, but also the multitudes of slovenly men with very dirty yet full heads of hair. If this theory had any validity, it would mean that the populations in countries where the opportunity and resources for personal hygiene are scarce would experience rapid hair loss in both male and female inhabitants. Of course, this is not the case. If the entire scalp is dirty, wouldn’t that mean that the whole scalp would bald at the same time?
Having good hygiene is a desirable trait that makes your existing hair more attractive. However, it doesn’t do much to prevent hair loss or cause hair to grow.
