August 22, 2022 • 1hr 57min
What Alcohol Does to Your Body, Brain & Health
Huberman Lab
Key Takeaways
- Alcohol is a toxin that causes cellular stress and damage when consumed. It is converted to acetaldehyde in the body, which is even more toxic.
- Even low to moderate alcohol consumption (1-2 drinks per day) can have negative effects on brain volume, gut health, stress levels, and cancer risk.
- Alcohol disrupts sleep quality, even if it helps you fall asleep initially. It reduces deep sleep and REM sleep.
- Regular alcohol consumption changes neural circuits related to habit formation, impulse control, and stress response. This can lead to increased drinking over time.
- Alcohol significantly disrupts the gut microbiome, killing beneficial bacteria and allowing harmful bacteria to proliferate. This contributes to inflammation.
- There is a 4-13% increased risk of breast cancer for every 10g of alcohol consumed daily (equivalent to 1 drink). This is due to alcohol's effects on DNA methylation.
- Alcohol increases conversion of testosterone to estrogen in both men and women, which can have negative health effects.
- To mitigate hangovers: support gut health, use safe cold exposure, replenish electrolytes, and avoid acetaminophen.
- Zero alcohol consumption is likely optimal for health. If you do drink, do so in moderation and take steps to offset the negative effects.
Introduction
In this episode, Dr. Andrew Huberman discusses the physiological effects of alcohol consumption on the brain and body. He covers how alcohol acts as a toxin, impacting cellular function, neurochemistry, and behavior. The episode examines both the short-term effects of intoxication as well as the long-term consequences of regular drinking, even at low to moderate levels. Dr. Huberman reviews the current scientific understanding of how alcohol affects sleep, stress, cancer risk, hormones, and more. He also discusses strategies to mitigate some of alcohol's negative effects for those who choose to drink.
Topics Discussed
Alcohol Metabolism and Cellular Effects (13:28)
Dr. Huberman explains how alcohol is metabolized in the body:
- Alcohol (ethanol) is converted to acetaldehyde, which is highly toxic
- Acetaldehyde is then converted to acetate, which can be used for energy
- This process uses up NAD, an important molecule for cellular function
- Alcohol and its metabolites can freely enter cells, causing widespread damage
He notes that alcohol provides "empty calories" with no nutritional value, as the energy from acetate cannot be stored beneficially.
Effects on Brain Function and Behavior (18:23)
Alcohol impacts multiple brain regions and neurotransmitter systems:
- Suppresses activity in the prefrontal cortex, reducing impulse control
- Disrupts memory formation in the hippocampus
- Alters serotonin and dopamine signaling, affecting mood
- Changes GABA signaling, leading to relaxation and sedation
These effects explain behavioral changes like reduced inhibition, memory blackouts, and mood swings during intoxication.
Long-Term Neural Changes from Regular Drinking (24:23)
Dr. Huberman discusses how consistent alcohol use, even at low levels, can lead to lasting changes in the brain:
- Strengthens neural circuits for habitual and impulsive behaviors
- Weakens circuits for behavioral control and decision-making
- Alters stress response systems, leading to higher baseline stress when not drinking
He notes these changes are reversible with abstinence, but may take 2-6 months to normalize.
Alcohol and Sleep (1:04:25)
While alcohol can help people fall asleep faster, it significantly disrupts sleep quality:
- Reduces time spent in deep slow wave sleep and REM sleep
- Leads to more fragmented sleep with frequent awakenings
- Results in less restorative sleep overall
Dr. Huberman emphasizes that alcohol-induced sleep is not equivalent to natural, high-quality sleep.
Effects on the Gut-Liver-Brain Axis (52:27)
Alcohol has major impacts on the gut microbiome and related systems:
- Kills beneficial gut bacteria indiscriminately
- Allows harmful bacteria to proliferate
- Increases intestinal permeability ("leaky gut")
- Triggers inflammation in the gut, liver, and brain
These effects can contribute to various health issues and may increase alcohol cravings.
Hangover Mechanisms and Mitigation (1:04:25)
Dr. Huberman explains the multiple factors contributing to hangovers:
- Dehydration and electrolyte imbalance
- Disrupted sleep
- Acetaldehyde toxicity
- Inflammation
- Stress hormone fluctuations
To reduce hangover severity, he suggests:
- Staying hydrated and replenishing electrolytes
- Supporting gut health with fermented foods
- Using safe cold exposure to boost adrenaline and dopamine
- Avoiding acetaminophen, which can stress the liver
Alcohol and Cancer Risk (1:37:11)
Dr. Huberman discusses the well-established link between alcohol and cancer:
- 4-13% increased breast cancer risk for every 10g of alcohol consumed daily
- Alcohol alters DNA methylation, potentially promoting tumor growth
- It also suppresses the immune system's ability to fight cancer cells
He notes that folate and B vitamin intake may partially offset this risk, but cannot eliminate it entirely.
Effects on Hormones (1:50:58)
Alcohol impacts hormone balance in both men and women:
- Increases conversion of testosterone to estrogen
- Can lead to relatively higher estrogen levels in both sexes
- May contribute to issues like reduced libido and increased fat storage
Dr. Huberman notes this effect occurs even with moderate alcohol intake.
Genetic Factors and Predisposition to Alcoholism (46:07)
Some individuals are more prone to developing alcohol use disorders:
- Genetic variants affecting serotonin, GABA, and stress response systems play a role
- Those with a family history of alcoholism are at higher risk
- Starting to drink at a younger age increases risk, regardless of genetics
Dr. Huberman explains that these factors influence how individuals respond to alcohol and their likelihood of developing problematic drinking patterns.
Conclusion
Dr. Huberman concludes that based on the current scientific evidence, zero alcohol consumption is likely optimal for health. He acknowledges that many people enjoy alcohol in moderation, and emphasizes that he is not telling anyone what to do. However, he encourages listeners to be aware of alcohol's negative effects, even at low levels of consumption.
For those who choose to drink, Dr. Huberman recommends:
- Drinking in moderation (if at all)
- Taking steps to support gut health, manage stress, and offset other negative effects
- Being aware of individual risk factors and family history
- Considering the long-term health implications of regular alcohol use
Ultimately, Dr. Huberman's goal is to provide listeners with the scientific information needed to make informed decisions about alcohol consumption in line with their health goals.
