Those drinking up to 62 grams of alcohol per day – equivalent to two glasses of wine – did not have an increased risk of recurrent heart attack, stroke, angina or death, compared to those who did not drink alcohol, found a large UK study.
Drinking up to 105 grams of alcohol per week – equivalent to 13 United Kingdom units of alcohol, less than six pints of medium-strength beer or just over a bottle of wine – may be associated with a decreased risk of heart attack, stroke, angina or death among those with cardiovascular disease (CVD), according to a study in BMC Medicine.
Chengyi Ding, the corresponding author, said: “Our findings suggest that people with CVD may not need to stop drinking in order to prevent additional heart attacks, strokes or angina, but that they may wish to consider lowering their weekly alcohol intake.
“As alcohol consumption is associated with an increased risk of developing other illnesses, those with CVD who do not drink should not be encouraged to take up drinking.”
Researchers from University College London found that, among people with CVD, those who drank up to 15 grams of alcohol per day – equivalent to less than two UK units, with one unit equal to half a pint of medium-strength beer or half a standard glass of wine – had a lower risk of recurrent heart attack, stroke, angina or death, compared to those who did not drink.
They also found that those who drank more than 62 grams of alcohol per day – equivalent to less than eight UK units – did not have an increased risk of recurrent heart attack, stroke, angina or death, compared to those who did not drink alcohol.
While drinking up to 15 grams of alcohol per day was associated with lower risks of heart attack, stroke, angina or death, the researchers found that those with the lowest risk drank between six and eight grams of alcohol per day – equivalent to less than one UK unit.
Those who drank six grams of alcohol per day had a 50% lower risk of recurrent heart attack, angina or stroke than those who did not drink. Those who drank eight grams per day had a 27% lower risk of death due to heart attack, stroke or angina, and those who drank seven grams per day had a 21% lower risk of death due to any cause, compared to those who did not drink.
The authors estimated the risk of heart attack, stroke, angina and death for 48,423 adults with CVD, utilising data obtained from the UK Biobank, the Health Survey for England, the Scottish Health Survey and from 12 previous studies.
Participants reported their average alcohol consumption and data on subsequent heart attacks, strokes, angina or death, over a period of up to 20 years, were obtained from health, hospital admission and death registry records.
The authors caution that their findings may overestimate the reduced risk of recurrent heart attack, stroke, angina and death for moderate drinkers with CVD. This is due to the under-representation of heavy drinkers and categorisation of former drinkers who may have quit drinking due to ill health as non-drinkers in some of the datasets included in their analyses.
Study details
Association of alcohol consumption with morbidity and mortality in patients with cardiovascular disease: original data and meta-analysis of 48,423 men and women
Chengyi Ding, Dara O’Neill, Steven Bell, Emmanuel Stamatakis and Annie Britton
Published in BMC Medicine on 27 July 2021. Volume 19, Article number: 167 (2021)
Abstract
Light-to-moderate alcohol consumption has been reported to be cardio-protective among apparently healthy individuals; however, it is unclear whether this association is also present in those with disease.
To examine the association between alcohol consumption and prognosis in individuals with pre-existing cardiovascular disease (CVD), we conducted a series of meta-analyses of new findings from three large-scale cohorts and existing published studies.
Methods
We assessed alcohol consumption in relation to all-cause mortality, cardiovascular mortality, and subsequent cardiovascular events via de novo analyses of 14,386 patients with a previous myocardial infarction, angina, or stroke in the UK Biobank Study (median follow-up 8.7 years, interquartile range [IQR] 8.0–9.5), involving 1640 deaths and 2950 subsequent events, and 2802 patients and 1257 deaths in 15 waves of the Health Survey for England 1994–2008 and three waves of the Scottish Health Survey 1995, 1998, and 2003 (median follow-up 9.5 years, IQR 5.7–13.0).
This was augmented with findings from 12 published studies identified through a systematic review, providing data on 31,235 patients, 5095 deaths, and 1414 subsequent events.
To determine the best-fitting dose-response association between alcohol and each outcome in the combined sample of 48,423 patients, models were constructed using fractional polynomial regression, adjusting at least for age, sex, and smoking status.
Results
Alcohol consumption was associated with all assessed outcomes in a J-shaped manner relative to current non-drinkers, with a risk reduction that peaked at 7 g/day (relative risk 0.79, 95% confidence interval 0.73–0.85) for all-cause mortality, 8 g/day (0.73, 0.64–0.83) for cardiovascular mortality and 6 g/day (0.50, 0.26–0.96) for cardiovascular events, and remained significant up to 62, 50, and 15 g/day, respectively.
No statistically significant elevated risks were found at higher levels of drinking. In the few studies that excluded former drinkers from the non-drinking reference group, reductions in risk among light-to-moderate drinkers were attenuated.
Conclusions
For secondary prevention of CVD, current drinkers may not need to stop drinking. However, they should be informed that the lowest risk of mortality and having another cardiovascular event is likely to be associated with lower levels of drinking, that is up to approximately 105g (or equivalent to 13 UK units, with one unit equal to half a pint of beer/lager/cider, half a glass of wine, or one measure of spirits) a week.
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