The claimEvidence A · guideline-tier
Moderate drinking protects the heart
The evidence
GBD 2018 + Mendelian randomization rule out a J-curve. Any dose raises cancer + all-cause mortality.
Why the claim spreads
The J-curve came from decades of observational studies that lumped people who quit drinking due to illness into the 'non-drinker' group — amplified by the 'French paradox' media wave and industry-funded research. It spreads because it makes a vice sound like self-care.
The mechanism, in brief
Ethanol (CH₃CH₂OH) is a small, simple, fast-moving molecule. Molecular weight is only 46 g/mol — four times smaller than glucose (180 g/mol). It's also amphipathic, with a water-soluble hydroxyl (-OH) and a fat-soluble ethyl (-CH₂CH₃). Being small and amphipathic means ethanol crosses every membrane in the body…
Sources (1)
- National Institute on Alcohol Abuse and Alcoholism. (2024). Alcohol Facts and Statistics. NIH NIAAA.