How Does Alcohol Consumption Affect Cardiovascular Health and Longevity?

The short answer

The apparent cardiovascular benefit of moderate alcohol consumption seen in older observational studies is substantially explained by confounding — 'sick quitter' bias (former drinkers who quit due to illness being classified as non-drinkers) and socioeconomic confounding. A 2019 Mendelian randomisation study found no protective cardiovascular effect of alcohol when genetic variants were used to control for confounding. There is no safe level of alcohol for cancer risk.

What the evidence actually shows

A 2018 global burden of disease analysis in The Lancet, using data from 195 countries and 28 million people, concluded that the safest level of alcohol consumption is zero, when considering the full spectrum of health outcomes including cancer. A 2011 meta-analysis by Ronksley et al. in the BMJ found that moderate drinking was associated with a 25% lower risk of cardiovascular mortality — but this analysis could not fully control for sick-quitter bias. A 2019 Mendelian randomisation study by Millwood et al. in The Lancet, using genetic variants that affect alcohol metabolism in 512,000 Chinese adults, found no evidence of a cardiovascular benefit from moderate alcohol consumption when confounding was controlled.

"The safest level of alcohol consumption is zero, when considering all health outcomes including cancer."

— GBD 2016 Alcohol Collaborators, The Lancet 2018

What the major health authorities say

MedlinePlus identifies alcohol use disorder as a major health concern and notes that heavy drinking is associated with liver disease, cardiovascular disease, and cancer. The NIA notes that alcohol can interact with many medications commonly taken by older adults and that older adults are more sensitive to alcohol's effects. The WHO and the US Dietary Guidelines Advisory Committee have both moved away from recommending moderate alcohol consumption as health-promoting, with the 2020–2025 Dietary Guidelines for Americans stating that 'drinking less is better for health than drinking more.'

Practical implications

If you currently drink moderately (1–2 drinks per day), the evidence does not strongly support stopping for cardiovascular benefit — but it also does not support continuing for cardiovascular benefit. The clearest reason to reduce or eliminate alcohol is cancer risk: even light drinking (one drink per day) is associated with a small but real increase in breast, colorectal, and oesophageal cancer risk. For older adults, alcohol impairs sleep quality, increases fall risk, interacts with common medications, and worsens cognitive function.

Where reasonable people still disagree

• Whether the Mendelian randomisation evidence fully refutes the observational cardiovascular benefit, or whether genetic variants in alcohol metabolism are imperfect instruments.
• Whether the type of alcoholic beverage (red wine vs beer vs spirits) matters for health outcomes, given the polyphenol content of red wine.
• The appropriate public health messaging around alcohol — whether zero-consumption recommendations are achievable and whether they may cause harm through stress and social isolation.