The health risks and benefits of moderate alcohol consumption are complex and remain a hot topic of debate. The data suggest that small amounts of alcohol may reduce the risk of certain health outcomes over time, but increase the risk of others, wrote Dana Bryazka, MS, a researcher at the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, Seattle, and colleagues, in a paper published in the Lancet.
“The amount of alcohol that minimizes health loss is likely to depend on the distribution of underlying causes of disease burden in a given population. Since this distribution varies widely by geography, age, sex, and time, the level of alcohol consumption associated with the lowest risk to health would depend on the age structure and disease composition of that population,” the researchers wrote.
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“We estimate that 1.78 million people worldwide died due to alcohol use in 2020,” Ms. Bryazka said in an interview. “It is important that alcohol consumption guidelines and policies are updated to minimize this harm, particularly in the populations at greatest risk,” she said.
“Existing alcohol consumption guidelines frequently vary by sex, with higher consumption thresholds set for males compared to females. Interestingly, with the currently available data we do not see evidence that risk of alcohol use varies by sex,” she noted.
Methods and results
In the study, the researchers conducted a systematic analysis of burden-weighted dose-response relative risk curves across 22 health outcomes. They used disease rates from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2020 for the years 1990-2020 for 21 regions, including 204 countries and territories. The data were analyzed by 5-year age group, sex, and year for individuals aged 15-95 years and older. The researchers estimated the theoretical minimum risk exposure level (TMREL) and nondrinker equivalent (NDE), meaning the amount of alcohol at which the health risk equals that of a nondrinker.
One standard drink was defined as 10 g of pure alcohol, equivalent to a small glass of red wine (100 mL or 3.4 fluid ounces) at 13% alcohol by volume, a can or bottle of beer (375 mL or 12 fluid ounces) at 3.5% alcohol by volume, or a shot of whiskey or other spirits (30 mL or 1.0 fluid ounces) at 40% alcohol by volume.
Overall, the TMREL was low regardless of age, sex, time, or geography, and varied from 0 to 1.87 standard drinks per day. However, it was lowest for males aged 15-39 years (0.136 drinks per day) and only slightly higher for females aged 15-39 (0.273), representing 1-2 tenths of a standard drink.
For adults aged 40 and older without any underlying health conditions, drinking a small amount of alcohol may provide some benefits, such as reducing the risk of ischemic heart disease, stroke, and diabetes, the researchers noted. In general, for individuals aged 40-64 years, TMRELs ranged from about half a standard drink per day (0.527 drinks for males and 0.562 standard drinks per day for females) to almost two standard drinks (1.69 standard drinks per day for males and 1.82 for females). For those older than 65 years, the TMRELs represented just over 3 standard drinks per day (3.19 for males and 3.51 for females). For individuals aged 40 years and older, the distribution of disease burden varied by region, but was J-shaped across all regions, the researchers noted.
The researchers also found that those individuals consuming harmful amounts of alcohol were most likely to be aged 15-39 (59.1%) and male (76.9%).
The study findings were limited by several factors including the observational design and lack of data on drinking patterns, such as binge drinking, the researchers noted. Other limitations include the lack of data reflecting patterns of alcohol consumption during the COVID-19 pandemic, and exclusion of outcomes often associated with alcohol use, such as depression, anxiety, and dementia, that might reduce estimates of TMREL and NDE.
However, the results add to the ongoing discussion of the relationship between moderate alcohol consumption and health, the researchers said.
“The findings of this study support the development of tailored guidelines and recommendations on alcohol consumption by age and across regions and highlight that existing low consumption thresholds are too high for younger populations in all regions,” they concluded.