Dietary Stress

Nutritional depletion
The body will strip the nutrients that it needs, during stress, from other areas of lower priority, as a temporary measure, but the body must be given a recovery period, or, these temporary measures may have an undesirable permanent effect.

A design fault, so to speak, exists in the stress response, in that we appear to be unable to respond in a different manner, to differing stressors . For example our physiology changes the same whether we are literally having to fight for our lives or are working to a tight deadline under time pressure.
Stress utilises certain nutrients in large quantities. If our diets do not contain these substances or we do not increase the supply of them during a stressful period, we could become deficient in these nutrients. This could have an adverse effect on our hair if the nutritional deficiency is not corrected.

Dietary stress
What is often not realised is that our very diet itself can make the body act as if it is stressed:

Caffeine (which is in tea, coffee and certain soft drinks) stimulates adrenal activity and with it, the very hormones above that affect our hair. The trend to "decaf " is not that much better as decaffeinated coffee contains other stimulants, such as Theobromine and Theophylline, which have a similar affect on the body as caffeine.

That does not mean we should all stop drinking tea and coffee immediately, but if we are concerned about our hair's health, we should at least monitor our caffeine intake.

Other than stimulating adrenal activity, caffeine interferes with the absorption of certain minerals. Iron absorption is reduced by about a third and calcium excretion is also promoted. The diuretic (a substance that causes more urine to be secreted in the body) action of tea and coffee also promotes the loss of the water soluble vitamins, and certain minerals.

Tannin which is also in tea, interferes with zinc, calcium, and iron absorption.

The other area of our diet which in an indirect way affects our hair, is our blood sugar levels.

Sugar and refined carbohydrates (white) such as bread, pastries, pasta and rice, cause an increase in blood sugar levels, to an extent that the hormone insulin has to be released from the pancreas to lower the level to within an acceptable range.

Often too much insulin gets released, as the above foods artificially cause a high blood sugar reading. When too much insulin is released, blood sugar levels may then fall too far and the adrenal glands again have to come into play, releasing adrenaline to increase blood sugar levels again. The body therefore reacts as if it is stressed, just because of the foods that have been consumed.

Alcohol, whilst a vasodilator (opener of small capillaries), also promotes an increase in the production of the hormone prolactin. We have seen above that this can increase adrenal hormone activity leading to the production and uptake of hormones that are harmful to hair.

Genetics and hormones have always been blamed for hair loss and these were studied in detail above. You cannot yet choose your genes, but you can choose the foods you eat and the drinks that you consume.