For just about any man or woman, hairs thins a bit with time, but a tendency toward early hair loss is genetic. However, evidence suggests that food choices influence the hormones that lead to hair loss, and so you may be able to postpone balding by modifying your diet.
Common hair loss depends on the hormone, testosterone.
In men, testosterone is made in the testicles and travels in the blood stream to the hair follicles. However, testosterone doesn't kill off the hair follicles directly. It is first converted, inside the follicle, to a much more powerful hormone called dihydrotestosterone (DHT). DHT has a great effect on the hair follicles, affecting them in different ways in different parts of the body. On the face and chest, DHT stimulates the growth of thick curly hair. This contrasts with its effect on the scalp where it makes hair thin out and eventually kills off the follicles altogether. The skin above the forehead and at the temples and crown is quick to turn testosterone into DHT and is particularly sensitive to its effects. Compared to Asian men, Westerners have more of the enzyme that converts testosterone to DHT and, consequently, have more bodily hair and more baldness.
The amount of testosterone in a woman's body is much less than that in a man, but if it increases for any reason, the hair on her scalp will become thinner. In women who have a strong genetic predisposition, even normal amounts of testosterone can cause hair loss.
If the influence of genetics if kept constant, rates of baldness seem to be affected by diet. For example, in Japan, as the traditional rice-based diet is replaced by meat and other Western influences, dermatologists have noticed that baldness appears to be commoner and to occur earlier. High-fat foods increase testosterone production and reduce the amount of sex hormone binding globulin that keeps it in check. As a result, there is more testosterone available to enter the hair follicles and cause hair loss. In contrast, low-fat high-fibre foods slow down hormone production and speed up hormone elimination.
Dietary changes may not be able to forestall baldness forever, but evidence does suggest that the right food choices may help you make the most of your genetic inheritance.
The foods that limit the effects of hormones are vegetables, fruits, grains, and legumes.
Cancer researchers and dermatologists have theorised that hormone levels at puberty may determine the likelihood of breast cancer or hair loss later in life. However, diet does influence hormone levels throughout life so, while those raised on low-fat vegetarian diets may be the healthiest, it is always beneficial to change your diet and restore hormone balance.