What role does Insulin play in longevity?

Insulin is a key metabolic hormone with a complex role in longevity. High insulin sensitivity and low fasting insulin are generally associated with healthier aging, reduced inflammation, and enhanced autophagy. Conversely, chronically elevated insulin—driven by poor diet and sedentary lifestyle—promotes insulin resistance, metabolic syndrome, and accelerated aging. Studies in centenarians and model organisms (worms, flies, mice) link reduced insulin/IGF-1 signaling to extended lifespan. However, human evidence is largely observational; interventional trials are limited. Lifestyle modifications (low-glycemic diet, exercise, time-restricted eating) can improve insulin sensitivity. Direct-to-consumer genetic tests for insulin-related variants have small effect sizes and should not replace clinical assessment. Caution: extreme dietary interventions require medical supervision.