Evidence check: Insulin in the context of Langlebigkeit

Insulin is a key metabolic hormone and its signaling pathway (insulin/IGF-1) is evolutionarily conserved in regulating lifespan. Reduced insulin/IGF-1 signaling extends longevity in model organisms (worms, flies, mice) and is linked to protection against age-related diseases in humans. Maintaining insulin sensitivity through diet, exercise, and weight management is associated with lower mortality and healthier aging. However, direct evidence from human longevity studies is correlational; randomized controlled trials are lacking. Consumer tests measuring fasting insulin or HOMA-IR can indicate insulin resistance, a risk factor for metabolic syndrome, but do not directly predict lifespan. The evidence for insulin's role in longevity is human-strong (epidemiological and mechanistic), but individual genetic background (e.g., MC4R variants affecting obesity) and lifestyle confounders matter. Safety note: Very low insulin (e.g., in type 1 diabetes) is dangerous. Lab results should be interpreted by a physician. No specific sources from the provided context directly address insulin and longevity.