A nutritiously balanced diet, low in processed foods, low in refined carbohydrates, high in green vegetables and fruit, lean protein is good for health. The question one asks is that, are there foods that aren’t good for hair?
To answer this, one needs to break down the class of foods and link it with scientific evidence that may show what vitamins and minerals could cause hair loss at high doses.
Vitamin A is important but can cause hair loss at high does. It is a fat soluble vitamin and the upper daily requirement is 700mcg in men and 600mcg in women. People should not over indulge in foods rich in this like liver or liver pate where more than once a week consumption can lead to vitamin A toxicity.
Selenium is a mineral that is important but in high doses, can also cause hair loss. One should avoid going over 400mcg of selenium to avoid toxicity. Hence, the food that is richest in this is Brazil nuts (a serving of 6 nuts has about 544mcg) and regular snacking should be avoided. 3 oz of salmon contains 41mcg of selenium.
Low vitamin D levels are associated in Alopecia areata. Caffeine can impair vitamin D absorption from the gut. So if one is taking this supplement, avoid taking tea or coffee at the same time. In some cases, Telogen effluvium can be caused by seborrheic dermatitis. in some people, dairy products like milk, cheese, cream can make this condition worse. (note high sugars can also cause this).
In summary, certain foods for certain people with certain conditions may have a negative effect on hair.