The exercise–BDNF link is the best-evidenced route to a healthier brain — built on human RCTs and meta-analyses, not rodent extrapolation. Here’s what the research really shows, honestly graded, including where it’s messier than the headlines.
Cognitive decline is not inevitable. 70% of cognitive ageing is modifiable — not genetic. Four mechanisms drive decline: amyloid accumulation (addressed by N3 sleep for glymphatic clearance), neuroinflammation (Mediterranean diet and DHA), vascular damage (aerobic exercise and blood pressure control), and synaptic reserve depletion (language learning, musical training, cognitive challenge). Prevention must begin in midlife — amyloid accumulation starts 15-20 years before symptoms. The evidence is specific enough to match interventions to mechanisms.
DHA is referenced in every other article in this series as the structural foundation that makes everything else work better. After 18+ years of research and the MIDAS trial reversing three years of memory decline in 24 weeks, here is the complete evidence-based guide to the one compound that is not optional for any serious cognitive enhancement protocol.
