How Does Alcohol Change Your Brain?

What really happens in your brain when you drink alcohol — and what are the long-term effects over a lifetime? In this episode of Health Matters, host Courtney Allison sits down with Dr. Hugh Cahill, a neurologist at NewYork-Presbyterian the One and Columbia, to break down the science behind alcohol’s impact on brain health.

They explore how alcohol affects neurotransmitters to create feelings of relaxation and euphoria, why it can impair memory, coordination, and judgment, and how even moderate drinking is linked to increase risk of brain shrinkage, vascular damage, mood disorders, and dementia. Dr. Cahill also explains the cumulative nature of alcohol’s effects and shares practical, evidence-based ways to protect your brain as you age — highlighting the powerful role of exercise, cardiovascular health, nutrition, sleep, and reducing alcohol intake.

Whether you’re curious about Dry January, worried about memory and aging, or simply want to make informed choices about your health, this conversation offers clear, expert insight into how your habits today shape your brain tomorrow.

Key Topics Covered

• How alcohol affects neurotransmitters (glutamate, GABA, dopamine, endorphins)
• Why alcohol causes relaxation, lowered inhibition, and impaired coordination
• Long-term effects: brain atrophy, neuron loss, memory impairment
• Alcohol as a neurotoxin
• Links between alcohol and:
  • Cumulative, lifelong impact of drinking—even at low to moderate levels
  • Role of exercise in promoting neurogenesis and brain resilience
  • Importance of cardiovascular health, vitamins (B1, B12), and metabolic health
  • Limited evidence that puzzles or brain games prevent cognitive decline
  • Practical brain-health strategies

Takeaway Message
Brain health is shaped by long-term habits. Because alcohol’s effects are cumulative and even moderate use is linked to structural and vascular brain changes, reducing intake — along with exercising and managing cardiovascular risk factors—can meaningfully protect cognitive function and quality of life as we age.

Expert Guest

Dr. Hugh Cahill is an M.D./Ph.D.-trained general neurologist providing comprehensive care for patients with a broad range of neurological conditions at NewYork-Presbyterian and Columbia. Dr. Cahill sees individuals with headaches, seizures, strokes, numbness, weakness, memory changes, and other common neurological concerns. Dr. Cahill as both a clinician and scientist supports an evidence-based approach to diagnosis and treatment, with an emphasis on careful evaluation and clear communication.

For more health and wellness news, visit NewYork-Presbyterian’s Health Matters website.