BDNF
Brain-Derived Neurotrophic Factor
Your brain's fertilizer. BDNF keeps neurons alive, grows new ones, and strengthens the connections that form memories. Low BDNF means a brain that's shrinking instead of thriving. Exercise is the most powerful way to boost it.
What BDNF Does
Neuron Survival
Protects existing neurons from dying. Without BDNF, neurons undergo apoptosis.
Neurogenesis
Stimulates growth of new neurons, especially in hippocampus (memory center).
Synaptic Plasticity
Strengthens synapses with use, weakens unused ones. The basis of learning.
Long-Term Potentiation
Essential for LTP - the cellular mechanism of memory formation.
Mood Regulation
Supports serotonin and dopamine systems. Low BDNF = higher depression risk.
Stress Resilience
Higher BDNF helps brain recover from stress and trauma.
How BDNF Signaling Works
Release
Neurons release BDNF in response to activity, exercise, fasting
TrkB Binding
BDNF binds to TrkB receptors on target neurons
Signaling Cascade
Activates MAPK, PI3K, PLCγ pathways for survival and growth
Gene Expression
Turns on genes for synapse formation, neuron survival, plasticity
BDNF Boosters
Exercise (Aerobic)
Single session raises BDNF. Regular exercise creates lasting elevation. Most powerful intervention.
Omega-3 Fatty Acids
DHA especially supports BDNF production. Fish, fish oil, algae oil.
Intermittent Fasting
Fasting stress upregulates BDNF as a protective response.
Sunlight Exposure
Morning light and vitamin D both support BDNF levels.
Sleep
Deep sleep consolidates learning through BDNF-dependent processes.
Curcumin
Turmeric compound that crosses blood-brain barrier, increases BDNF.
Social Connection
Social engagement and novel experiences stimulate BDNF.
BDNF Reducers
Chronic Stress
Prolonged cortisol suppresses BDNF, shrinks hippocampus. Major factor.
Sugar / High Glycemic Diet
Blood sugar spikes and crashes lower BDNF. The brain hates sugar swings.
Sedentary Lifestyle
No exercise = no BDNF boost. The brain needs movement.
Social Isolation
Loneliness is toxic to BDNF and brain health.
Sleep Deprivation
Poor sleep = poor BDNF. The brain repairs and grows during sleep.
Aging
BDNF naturally declines with age. Exercise offsets this decline.
The BDNF Val66Met Polymorphism
About 30% of people carry a genetic variant (Met allele) that reduces BDNF secretion. This affects memory, stress response, and depression risk.
Val/Val (typical)
Normal BDNF secretion. Standard stress resilience.
Val/Met (carrier)
Reduced BDNF secretion. May need more lifestyle support.
Met/Met (homozygous)
Significantly reduced secretion. Higher anxiety, memory impacts. Exercise even more important.
If You're a Met Carrier
- •Exercise is even MORE important for you - it can overcome genetic disadvantage
- •Stress management is critical - you may be more stress-sensitive
- •Omega-3s and curcumin may provide extra benefit
- •Consider cognitive training to strengthen compensatory pathways
BDNF and Health Conditions
Depression
Low BDNF is a consistent finding. Antidepressants work partly by raising BDNF. Exercise is as effective as medication.
Anxiety
BDNF helps regulate fear circuits. Low levels = persistent anxiety, poor fear extinction.
Alzheimer's Disease
BDNF drops early in Alzheimer's. Lower BDNF = faster cognitive decline.
PTSD
BDNF helps process and extinguish traumatic memories. Low BDNF keeps trauma "stuck."
Obesity
BDNF regulates eating behavior. Low BDNF increases appetite and food reward.
Cognitive Decline
Age-related BDNF decline contributes to memory loss. Exercise preserves BDNF into old age.
