Study Finds Safe Alcohol Consumption Guidelines May Not Be Strict Enough
Alcohol consumption was roughly associated with a higher risk of stroke, coronary disease excluding myocardial infarction, heart failure, fatal hypertensive disease, and fatal aortic aneurysm.
Among current drinkers without a previous diagnosis of cardiovascular disease, the threshold for the lowest risk of all-cause mortality is about 100 g of alcohol consumed per week, or about 5-6 glasses of wine or pints of beer, according to a study published in the Lancet.
The research team, led by Angela M Wood, PhD, from the Department of Public Health and Primary Care, University of Cambridge, in the UK, conducted a combined analysis of individual-participant data from 3 large-scale data sources. To be eligible, participants had to have information recorded about their alcohol consumption amount and status (ie, nondrinker vs current drinker), and age, sex, history of diabetes and smoking status, at least 1 year of follow-up after baseline, and no baseline history of cardiovascular disease.
The main analyses focused on current drinkers, whose baseline alcohol consumption was categorized into 8 predefined groups according to the amount in grams consumed per week. The researchers assessed alcohol consumption in relation to all-cause mortality, total cardiovascular disease, and several cardiovascular disease subtypes.
Of the 786,787 participants with sufficient information for inclusion, 186,875 (19%) reported not drinking at baseline, leaving 599,912 current drinkers without a history of cardiovascular disease at baseline. Baseline year of recruitment ranged from 1964 to 2010. The mean age of the participants was 57 years. A total of 265,910 (44%) of 599,912 participants were women, and 128,085 (21%) were current smokers. About 50% reported drinking more than 100 g of alcohol per week, and 8.4% drank more than 350 g per week.
During 5.4 million person-years, there were 40,310 deaths from all causes (including 11,762 vascular and 15,150 neoplastic deaths), and 39,018 first-incident cardiovascular disease outcomes, including 12,090 stroke events, 14,539 myocardial infarction events, 7,990 coronary disease events excluding myocardial infarction, 2,711 heart failure events, and 1,121 deaths from other cardiovascular diseases.
Alcohol consumption was roughly linearly associated with a higher risk of stroke (HR per 100 g per week higher consumption, 1.14), coronary disease excluding myocardial infarction (1.06), heart failure (1.09), fatal hypertensive disease (1.24), and fatal aortic aneurysm (1.15).
In contrast, increased alcohol consumption was log-linearly associated with a lower risk of myocardial infarction (HR, 0.94). In comparison to those who reported drinking >0–≤100 g per week, those who reported drinking >100–≤200 g per week, >200–≤350 g per week, or >350 g per week had a lower life expectancy at age 40 years of approximately 6 months, 1–2 years, or 4–5 years, respectively.
“The main finding of this analysis was that the threshold for lowest risk for all-cause mortality was about 100 g per week,” the authors concluded. “For men, we estimated that long-term reduction of alcohol consumption from 196 g per week (the upper limit recommended in US guidelines) to 100 g per week or below was associated with about 1–2 years of longer life expectancy at age 40 years.”
Wood AM, Kaptoge S, Butterworth AS, et al. Risk thresholds for alcohol consumption: combined analysis of individual-participant data for 599 912 current drinkers in 83 prospective studies. Lancet. 14 April 2018. DOI: https://doi.org/10.1016/S0140-6736(18)30134-X