The popular belief that moderate alcohol consumption protects against heart disease could be a complete myth, suggests new study. (Photo: <a href= http://www.shutterstock.com/pic-150111035.html target=”blank_”>Shutterstock</a>)

The popular belief that moderate alcohol consumption protects against heart disease could be a complete myth, suggests new study. (Photo: Shutterstock)

Study: Alcohol does not have any health benefits

Large study casts doubt on the health benefits of alcohol. It might be necessary to cut alcohol completely to lower risk of heart disease.

Jonas Salomonsen

Published 8 November 2015 - 06:25

You may have heard that one alcoholic drink a day is good for you as it can stave off heart disease and help you to live longer.

But not all scientists agree. And now, a large genetic study has thrown a wet blanket over the situation.

Their advice is that everyone should lower their alcohol intake to zero, if they want to reduce the risk of developing heart disease. This also applies to moderate drinkers.

"I was surprised. I actually thought that a glass of wine a day somehow had beneficial effects. But I don’t think that anymore," says Lasse Folkersen, a postdoc with the Institute for Systems Biology at the Technical University of Denmark.

Modern genetic engineering reveals the effects of alcohol

Folkersen is one of many the scientists involved with a large study, which analysed the alcohol habits, genes, and disease history of 261,991 Europeans.

The researchers took advantage of their knowledge of a particular variant of the gene ADH1B, which produces an acute oversensitivity to ethanol (alcohol) and helps the carriers of this genetic variant to drink less.

A small number of study participants carried this 'reduced alcohol variant', and this group had a 10 per cent reduced risk of developing heart disease and a 17 per cent reduced risk of blood clots than those with the regular gene.

Folkersen and colleagues also looked at people who drank relatively little--less than seven drinks per week--and they observed the same trend. It seemed that even in this group of light drinkers, the risk of heart diseases could be further reduced if they cut down on their already modest alcohol intake.

The study is supported by the Tryg Foundation and was published in July 2014 in the scientific journal British Medical Journal.

Alcohol's effect is disputed

The results completely contradict a common interpretation of previous population studies, which examined the relationship between alcohol intake and cardiovascular disease.

"Many studies have shown that the relationship was U- or J-shaped. That means that the risk decreased if you drank moderately compared to if you drank nothing at all, and then increased again [if you drank a lot],” says Allan Linneberg, a clinical professor at Copenhagen University Hospital, Denmark. He is the head of section for Research for Prevention and Health, which provided data for the new study.

“How to interpret this relationship has been discussed a lot. Some have interpreted it in such a way as to suggest that one drink a day protects against heart disease when compared with those who don’t drink at all," says Linneberg.

But despite a clear correlation between moderate alcohol intake and a reduced risk of heart disease, it is not certain whether the underlying cause was indeed alcohol. Rather, it could be some other trait shared by the moderate drinkers.

Alcohol myths set to fall?

The surprising conclusions not only question whether moderate alcohol consumption actually protects us against heart disease, it also questions the previously supposed links between moderate alcohol intake and a myriad of other diseases, including dementia, diabetes, obesity and asthma.

"I’m a little sceptical that a drug could have a positive effect on so many different diseases. It would be hard to explain from a biological point of view," says Linneberg.

Linneberg is now using the same methods as Folkersen to identify precisely how alcohol could affect asthma and other allergies. His hypothesis is that alcohol increases the risk of asthma and allergy outbreaks.

"We know that many people have allergic reactions when they drink alcohol. They get an itchy nose, a skin rash, they sneeze, and some even develop a little asthma,” says Linneberg. “We think that alcohol might trigger an allergic reaction in the immune system.”

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Read the Danish version of this story on Videnskab.dk

Translated by: Catherine Jex