It’s a widely recognised idea in nutrition that moderate drinking is ‘healthy’. This advice is based on evidence which links moderate drinking with improved health outcomes (notably a reduced risk of death from heart disease) compared to not drinking at all.
However, I remember more than 10 years ago sitting in a presentation given by an American nutritional physician, who made the point that such research is potentially biased by the fact that non-drinkers can be reformed drinkers, and this group may include ex-alcoholics (alcoholism may damage heart health) or individuals who have been advised not to drink or taken it upon themselves not to drink because they have had a heart attack or been diagnosed with heart disease.
Because of this, to make a better judgement of the impact alcohol has on health it would be better to compare the health of moderate drinkers, say, with those who have never drunk alcohol (lifelong teetotallers, not reformed drinkers) or at least individuals who have not drunk alcohol for a very long time.
With this in mind, I was interested to read a recent study that looked at heart disease risk and risk of death in both former drinkers and also long-term abstainers of alcohol . The study was a meta-analysis, and amassed data from 38 epidemiological studies. Risk of heart disease ‘morbidity’ (e.g. a diagnosis of heart disease or heart attack) was the same in these two groups. However, for heart disease ‘mortality’ (essentially, fatal heart attacks), there were significant differences between the two groups.
In men, former drinkers were at a 25 per cent increased risk of heart disease mortality compared to long-term abstainers.
In women, former drinkers were at a 54 per cent increased risk of heart disease mortality compared to long-term abstainers.
The researchers concluded that in future analyses, former drinkers should be excluded from the non-drinker group. This way, the results will not be so biased by the fact that former drinkers tend to be at increased risk of death from heart disease compared to long-term abstainers.
Previous studies will almost certainly been subject to this bias, and will therefore have ended up with results that make moderate drinking appear to be associated with improvements in health outcome that do not exist (or are smaller) in reality.
With New Year’s eve approaching, I suppose an article highlighting the fact that the health ‘benefits’ of drinking alcohol have almost certainly been overstated will not go down so well. But, I’m also not of the mind that everything that passes our lips need be healthy. On the other hand, if we are going to drink alcohol, we may as well do it in a way that may mitigate any negative effects. I wrote a blog post about this recently, which you can find here.
1. Roerecke M, et al. Ischemic Heart Disease Mortality and Morbidity Rates in Former Drinkers: A Meta-Analysis. Am J Epidemiol 14 Dec 2010 [Epub ahead of print]