Re intermittent fasting - "not clinically relevant" in that its effect on insulin in itself isn't relevant, or that insulin resistance itself doesn't have a clinically significant relationship to dementia?
I'm not a faster, don't have a dog in this fight, just curious as have seen a few papers & articles in recent years that seem to suggest a relationship between T2D / metabolic syndrome and dementia, but these may have since been debunked?
Melatonin helps with sleep disorders... for people with sleep disorders. There is a synthetic analog called Ramelteon.
Intermitent fasting has curious effects on insulin resistance, but not clinically relevant.
Probiotics reduce incidence and severity of traveler's diarrhea... for travelers. It has been comercially available for a while.
Like Ivermectin, which is not snake oil, but is also being sold for the same purposes as snake oil.