Mangan has gone down another rabbit hole in his health research, prompted by a reader’s unusual experience:
This started when a reader told me that he had started donating blood after reading this site and my book on iron.
He said that he had had seborrheic dermatitis of many years standing. (Click here if you want to see what that looks like.) It’s basically something like really terrible dandruff, but can be on any part of the body. He had tried both anti-fungal medication and topical steroids, and nothing worked. Since it didn’t bother him much, he quit worrying about it.
After his first blood donation, it started clearing up, and after his third donation, it completely disappeared.
What in the world? It turns out that both dandruff and seborrheic dermatitis are linked to a fungal infection by the fungus Malassezia. So is tinea versicolor, a skin infection; when I lived in Sierra Leone, virtually everyone had it to some degree.
Dandruff is caused by a fungal infection.
All microorganisms that invade man and cause disease require iron. (Every living thing requires iron.) Withholding iron from microbes is at the center of an evolutionary arms race. It stands to reason that donating blood can treat fungal infections of the skin by lowering skin iron levels. (Donating blood will also make you look younger.)
Shampoo that contains salicylate and ciclopirox effectively treats dandruff. Ciclopirox is an iron chelator (attaches and removes iron). So is salicylate. By attaching and removing iron, they deprive fungus of required growth material, it dies, and dandruff is treated.
Ketoconazole, an anti-fungal chemical that works by inhibiting fungal steroid synthesis, also treats dandruff.
Male pattern baldness has been linked to fungal infection as well, and the antifungal drug ketoconazole treats male pattern baldness just as well as minoxidil (Rogaine).
If this holds true for many or all cases of male pattern baldness (androgenic alopecia), then our notions of why some men go bald (that it’s due to testosterone metabolites) may be all wrong. Curiously, folklore has it that hats cause baldness — perhaps by giving fungus a warm, moist environment in which to grow?
Male pattern baldness is also associated with heart disease. Severe baldness was associated with a 2.5 fold greater risk of death from heart disease. Huge increase.
If fungal infection in the skin causes both male pattern baldness and dandruff, then iron is implicated, because all invasive microorganisms must take iron from their hosts.
High iron (ferritin) is also associated with heart disease. The mechanism usually postulated is increased oxidative stress of the walls of arteries; iron is a very reactive metal capable of damaging biological structures.
But another mechanism might be the stimulation of fungal growth. “Occult fungal infection is the underlying pathogenic cause of atherogenesis” (from the journal Medical Hypotheses).