what do you make of this theory? is it possible that there could be any truth (or even half truth) to it?
The site you linked to doesn’t offer much besides unproven theories presented by an unknown author. It doesn’t look like the site has even been updated in almost a decade.
There has always been talk that sebum is the cause of hair loss, but sebum is the normal exudate from the glands on the hair follicle and when produced, it is completely normal. Now with that said, we see many people who are concerned about hair loss or just poor hair and when looking for something to blame, sebum always seems to come up. Sorry, folks — sebum does not cause hair loss.
Also, to perpetuate this old wives’ tale, you will always find some business that makes money helping you clean your hair better so that the “evil” sebum does not do its damage. Everyone needs to make a living, so I guess the sebum cleaners have been around for as long as people have focused on their hair problems and are willing to give up their hard earned money.