How are BDNF and longevity related?

BDNF (Brain-Derived Neurotrophic Factor) is a protein that supports neuronal survival, growth, and synaptic plasticity. Aging is associated with declining BDNF levels, which may contribute to cognitive decline and increased risk of neurodegenerative diseases. Observational studies link higher BDNF levels to better cognitive aging and, in some cases, longer lifespan. However, the evidence is largely correlational and mechanistic; no human RCT has proven that raising BDNF directly extends lifespan. The common rs6265 polymorphism (Val66Met) reduces activity-dependent BDNF secretion and is associated with modestly increased risk of memory decline in older adults, but the effect is small. Lifestyle interventions such as aerobic exercise, intermittent fasting, and omega-3 intake can upregulate BDNF. In summary, BDNF is a relevant marker for brain health and healthy aging, but its role in longevity is indirect and context-dependent. Evidence level: human-moderate (observational, mechanistic).