> acarbose was one of five molecules shown to increase lifespan
Rapacmycin, acarbose, glycine, canagliflozin and 17-a-estradiol [1]. Acarbose’s side effects include “flatulence (78% of patients) and diarrhea (14% of patients)” [2]. (It also appears to be hard on the liver.)
Most well-documented pharmacological intervention to increase lifespan in aspirin. The most well-documented non-pharmacological is caloric restriction (with some evidence showing protein restriction).
When insulin stops doing what it's supposed to (= diabetes) then a lot of bad stuff happens. Improving insulin function (insulin sensitivity) is the main principle behind many current diet-based health interventions such as intermediate fasting, keto dieting, apple cider vinegar, and so on.
Diabetes drugs improve or replace the role of insulin, through differing mechanisms, so it makes sense that they would have some of the same benefits.
It would be interesting to see acarbose's lifespan effects compared to inulin in mice. Inulin has similar side effects in some people, hence why sunchokes/Jerusalem artichokes are also called "fartichokes".
> safe to discount any study that indicates significant health effects from a nonessential amino acid
One, that’s too much confidence for a topic we do not understand well. Two, the study found—with startlingly high confidence and a meaningful, if small, effect size—glycine “can mitigate methionine toxicity,” the latter being an essential amino acid [1].
Well the research is on rats. not to mention that the glycine specific one is funded by a glycine selling company. But despite all that, glycine has strong research backing it especially for reducing inflammation and allergies.