for 50+ years every medico affirmed that ulcers are caused by stress which makes your stomach produce too much acid and the best treatment is expensive antacids like zantac.
after that claim was challenged, the "experts" ran the doctor out of the country. he went on to prove that ulcers are caused by a treatable bacteria and won the nobel prize.
cancer and diabetes are reversible with dietary change, exercising, and mineral supplements. ever hear of berberine? it's as effective as metformin but not as expensive.
actor dirk benedict overcame cancer and wrote a book about it, see
the health industry strives to keep people on drugs rather than dealing with the cause of their problem because that's where the big money is.