Alcoholic drinks are in the news again, served with a twist. A large cohort study saw a familiar J-shaped curve detailing risk for new atrial fibrillation (AFib) in which the risk rose steadily with greater number of drinks per week, except at the lowest levels of alcohol intake.
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There, the curve turned the other way. Light drinkers overall showed no higher AFib risk than nondrinkers, and the risk was lowest at any degree of alcohol intake up to 56 g per week.
On closer analysis of risk patterns, the type of alcoholic beverage mattered.
Alcohol content per drink was defined by standards in the United Kingdom, where the cohort was based.
The risk of AFib also didn’t climb at low intake levels of white wine or with “very low” use of liquor or spirits. But it went up consistently at any level of beer or cider consumption, and to be sure, “high intake of any beverage was associated with greater AF[ib] risk,” notes a report on the study published July 27, 2021, in JACC: Clinical Electrophysiology.
The results, based on more than 400,000 adults in the community, “raise the possibility that, for current consumers, drinking red or white wine could potentially be a safer alternative to other types of alcoholic beverages with respect to AF[ib] risk,” the report proposes.
The J-shaped risk curve for new AFib by degree of alcohol consumption follows the pattern sometimes seen for cardiovascular risk in general. But the intake level at which AFib risk is flat or reduced “is at a far lower dose of alcohol than what we’ve seen for cardiovascular disease,” lead author Samuel J. Tu, BHlthMedSc, said in an interview.
“That being said, even with the threshold sitting quite low, it still tells us that cutting down on alcohol is a good thing and perhaps one of the best things for our heart,” said Mr. Tu, University of Adelaide and Royal Adelaide Hospital, who also presented the findings at the Heart Rhythm Society 2021 Scientific Sessions, held in Boston and virtually.
How much alcohol is in a drink?
In a caution for anyone looking to beer, wine, or liquor to protect against AFib, or at least not cause it, the weekly number of drinks associated with the lowest AFib risk may be fewer than expected. That bottom of 56 g per week works out to one drink a day or less for British and only four or fewer per week for Americans, according to the study’s internationally varying definitions for the alcohol content of one drink.
For example, a drink was considered to have 8 g of alcohol in the United Kingdom, 14 g in the United States and some other countries, and up to 20 g in Austria. Those numbers came from definitions used by the respective national health agencies, such as the National Health Service in the United Kingdom and Centers for Disease Control and Prevention in the United States, Mr. Tu explained.
“They all defined standard drinks slightly differently. But wherever we looked, the threshold we found was far lower than what our governments recommend” based on what is known about alcohol and overall cardiovascular risk, he said.