A new study looks at wine intake and reduced heart risk but don't toast the conclusions yet!

A few wines a week may slightly decrease risk of irregular heart flutters, according to a study published in Clinical Electrophysiology – but the jury is still well and truly out on whether wine is good for your health, and responsible drinking is still required.

A recent study, involving the University of Adelaide and Flinders University, analysed how small quantities of alcohol affect the risk of arterial fibrillation (AF) – rapid heartbeat that can lead to heart complications. the team found that found that, while drinking larger volumes of alcohol always has negative outcomes, the lowest risk of AF occurred in people who consumed less than seven glasses of wine a week, even compared to people who drank none.

“AF can result in a range of symptoms including palpations, breathlessness, fatigue, dizziness and difficulty exercising,” says lead author Samuel Tu of the University of Adelaide and Royal Adelaide Hospital.

“In the 1970’s, we found that binge drinking was associated with developing AF – the so called “Holiday Heart” syndrome, noted when patients would present to emergency departments in the hours or days following festive holidays where lots of drinking was involved. 

“What wasn’t very well known prior to our study was whether lower levels of alcohol consumption are associated with developing AF. Some studies have suggested that any consumption of alcohol (for example, 1 drink/day) is associated with an increased risk of developing AF.

“Others however have suggested otherwise – that low amounts of alcohol consumption may not increase your risk of AF.”

This research sought to clarify what the threshold of “low amounts of alcohol” was.

To do this, the team studied 400,000 middle-aged, predominantly Caucasian individuals from the UK Biobank, with collected data from over a median 11 years. Researchers assessed how many AFs occurred over that time-period compared to how many drinks their subjects reported having.

“We found that those who consumed less than 6 Australian standard drinks of alcohol/week had the lowest risk of developing AF, says Tu.

“We also found that beer and cider consumption was associated with a greater risk of AF, compared to red wine and white wine consumption. These results were similar in both women and men.”

There was a small dip in risk of AF when among people who consumed between 1 and 6 drinks, but only with wine. While no extra risk was observed for people who drank three measures of spirits a week, there was also no dip.

With all alcoholic beverages, the risk of AF began to increase steadily with the amount of drinks consumed, regardless of what type of alcohol it was.

Importantly, the paper does not endorse drinking wine or alcohol as a heart health benefit but clarifies how to drink responsibly to avoid AF.

“Our findings suggest that responsible consumption of alcohol of up to 6 drinks per week may be safe in terms of minimising your risk of atrial fibrillation,” says Tu.

“Notably, this threshold sits below what is currently recommended by the NHRMC for healthy Australians, which is 10 standard drinks per week.

“Additionally, for those who currently consume alcohol, drinking red or white wine could potentially be a safer alternative to other types of alcoholic beverages.”

Of course, a small decrease in the risk of AF when some alcohol is consumed can easily be interpreted as though wine is good for the health. But caution is required.

“People like to positively reinforce their existing viewpoints,” says Simone Pettigrew, Head of Food Policy at the University of New South Wales.

“This is partly due to how we process information – new information is tagged to existing knowledge in our brains, so it’s easier to assimilate things that gel with what we already think/know.

“This is called a process of developing associative networks. Plus we have selective attention and recall, so we tend to focus on things we are most interested in and that we consider most beneficial to us.”

The paper was also accompanied by an editorial by Thomas Dewland and Gregory Marcus, medical doctors from the University of California, that explains that, while the statistical analysis was robust, the results of the paper need to be considered within the context of alcohol research in general.

They say that it isn’t uncommon for studies to show a small dip in risks for some health outcomes when only a “few drinks” per week are consumed, but that it depends on the type of alcohol and the health risk in question.

They also say it is difficult to draw a line at what “a few drinks” means, because different countries have different standards – for example, the study used the UK standard of a drink (8 grams of alcohol), which is lower than the US standard (14g) and the Australian standard (10g).

“What do we tell our patients?” ask Dewlands and Marcus in their editorial. “For secondary AF prevention, the message should be alcohol abstinence, especially if alcohol is a personal trigger for acute AF episodes.

“For primary AF prevention, it is possible that continued consumption of some alcohol may be reasonable, but the exact threshold is unclear and is likely a very low amount.”