Despite previous studies on the health benefits of moderate alcohol consumption including reduced risk of cardiovascular disease and all-cause mortality, researchers suggest that the benefits may be overestimated in a new study published in the journal The BMJ.
Heavy alcohol consumption increases the risk of high blood pressure, stroke, liver diseases, and cancer, among other health conditions. But what about moderate alcohol consumption. Current recommendations define moderate drinking as one drink per day for women and one to two drinks per day for men.
Previous studies have suggested health benefits from moderate alcohol consumption, including a January study that suggests that drinking up to seven alcoholic drinks per week may lower the risk of developing heart failure in the future.
However, the authors of the present study argue that many of the past studies associating alcohol use with health benefits are “contentious,” citing confounding factors such as categorizing former drinkers and never drinkers into one group, often as a control group.
Note the authors:
“Specifically, former drinkers have been found to exhibit poorer self-reported health, higher levels of depression and increased risk of mortality than never drinkers. As such, protective associations identified among light drinkers may be less a consequence of a beneficial biological mechanism and more a statistical artifact resulting from the application of a pooled non-drinking category.”
The researchers also note that very few past studies have included older participants.
With the limitations of past research in mind, the researchers of the present study sought to examine the suitability of age specific limits for alcohol consumption and to explore the association between alcohol consumption and mortality in different age groups.
Using data from the Health Survey for England between 1998 2008, the researchers assessed 18,368 adults between the ages of 50 and 64 years old and 34,523 adults over the age of 65. Participants who reported consuming alcohol at some point during the past 12 months were categorized as “occasional drinkers” and were further divided into groups based on weekly alcohol consumption. Participants who reported consuming alcohol in the past week were categorized as “current drinkers” and were also further divided into groups based on weekly alcohol consumption.
Between 1998 and 2002, 4,102 deaths occurred over a median follow-up of 9.7 years. Between 1999 and 2008, 4,220 deaths occurred over a median follow-up of 6.5 years
Upon analyzing unadjusted models, the researchers identified reduced mortality risk across a wide range of alcohol usage among men and women in both age groups.
However, after excluding former drinkers and accounting for other confounding factors such as socioeconomic status and lifestyle, the researchers identified only significant mortality benefits among men between the ages of 50 and 64 who consumed 15 to 20 units of alcohol a week or up to 1.5 units on the heaviest day and among women age 65 and older who drank less than 10 units a week or up to 4.5 units on the heaviest day.
Comment the researchers:
“The findings from this study suggest that beneficial associations typically identified between low-intensity alcohol consumption and all-cause mortality may, in part, be attributable to an inappropriate selection of a referent group and weak adjustment for confounders.
“The effect of such biases should therefore be borne in mind when evaluating findings from alcohol health studies – particularly when seeking to extrapolate results to the population level.”
Concludes Professor Mike Daube of Curtin University in Australia in an accompanying editorial:
“Firstly, in health as elsewhere, if something looks too good to be true, it should be treated with great caution. Secondly, health professionals should discourage suggestions that even low level alcohol use protects against cardiovascular disease and brings mortality benefits.”
“Thirdly, health advice should come from health authorities, not from the alcohol industry, and, finally, the alcohol industry and its organisations should remove misleading references to health benefits from their information materials.”
Because the current study suggests that the protective benefits of alcohol may be explained by the effect of selection biases across age-sex strata, additional research appears necessary to further explore the associations.
Alcohol’s evaporating health benefits: http://www.bmj.com/content/350/bmj.h407
All cause mortality and the case for age specific alcohol consumption guidelines: pooled analyses of up to 10 population based cohorts: http://www.bmj.com/content/350/bmj.h384
Mortality benefits of moderate alcohol use ‘may be overestimated’: http://www.medicalnewstoday.com/articles/289189.php
Bubbling Beer Glass: http://www.freeimages.com/photo/642599