yeah sure but you can apply that logic to practically everything as existence in and of itself is stressful on the human body. i don't think insulin in low/moderate dosages is going to cause any issues, specially considering it is a naturally produced hormone and the causes of metabolic syndrome stem mostly from obesity, sedentary lifestyle and excessive food intake, not the insulin itself.
Well I'm talking from a standpoint of an "anti-aging" taken to the extreme (for ex. fried foods cause an intracellular accumulation of Advanced Glycation End products aka AGEs.. So while one can eat fried foods in moderation and stay healthy, not get a colon cancer/etc.. from a standpoint of achieving a most optimal health and longevity - fried foods should be crossed out from a diet all together. As you could postpone the worsening of your sight due to damaged proteins by AGEs in your lens, but you just won't know that as there's only one way of two in this case, and you couldn't go back to check another one, if you know what I mean, as one of the examples.). So basically what I want to say is that insulin, according to a decent amont of studies on various organisms is tied to some major pro-aging genetic pathways very closely, and while it may not harm you in an obvious way that you could pin point insulin as a culprit, it may "harm" you in a "passive mode", as rendering various mollecular mechanisms in your body less effective, compared to what they'd be without a prior slin surges, on the long run.
