Can BDNF help with blood sugar?

BDNF (Brain-Derived Neurotrophic Factor) has been linked to improved insulin sensitivity and glucose uptake in animal and some human observational studies. However, the evidence is primarily mechanistic and insufficient for clinical recommendations. Elevated BDNF levels may theoretically support glucose metabolism, but direct causal evidence from randomized controlled trials is lacking. Moreover, BDNF is not orally bioavailable as a supplement and is not recommended for blood sugar management. Genetic variants in the BDNF gene (e.g., rs6265) are associated with obesity and insulin resistance, but the effect size is small and not deterministic. Established lifestyle interventions—diet, exercise, and medical treatment when indicated—remain the cornerstone of blood sugar control. The evidence level is best described as 'mechanistic'.