Do you think enjoying half a glass of wine per day poses the equivalent health risk of smoking two packs of cigarettes a month? Well that’s what a new report published in BMC Public Health insinuates.
More specifically, the authors equate the cancer risk that arises from smoking five weekly cigarettes for men and ten for women to that of a bottle of wine. The findings may be portrayed by some as gospel, but don’t put down the glass just yet.
First of all, the authors of this meta-analysis were unable to control for cigarette use in the studied population. Therefore, the findings around the effects of moderate drinking are likely tainted by the health outcomes of those who also smoked.
Moreover, the analysis doesn’t take into account behavior duration, which could significantly skew the results. For example, someone who partakes in moderate drinking now may have participated in more dangerous consumption patterns earlier in life. Or in the case of cigarettes, did someone pick up smoking as a teen and continue with the habit, or did they just begin? This is a critical factor, as many cancers are connected to long-term, consistent cigarette usage.
It’s also important to note the analysis did not consider a number of other factors, such as age — a crucial element when examining cancer risk, given that a diagnosis naturally becomes more likely later in life — or the many other health consequences that can arise from smoking besides cancer. Notably, they left out out the greater likelihood of heart disease and similar conditions that negatively impact other organs.
Yet another flaw is the report’s failure to control for the inherent weaknesses and questionable accuracy of survey-based observational studies — the type of data in which the analysis is based.
There are enough holes in this meta-analysis to question the topline findings. It’s widely accepted that smoking poses a major threat to one’s health and begins with the first incident of consumption — a pattern that does not apply to alcohol.
The flaws in this specific report echo those included in a number of other meta-analyses released over the past year around the issue of moderate drinking and health. Not only did the prior analyses fall prey to similar pitfalls as those highlighted above, but they also confounded relative risk with absolute risk, and in a manner certain to generate hyped-up media coverage. For example, if you have a 1% risk of getting cancer, and your risk increases to 1.1%, that can be rather deceptively sold as a 10% increase in risk.
One of the prior studies — published in The Lancet — proclaimed that moderate drinking led to a 10 percent increase in the likelihood of being diagnosed with breast cancer. But in terms of absolute risk, the chances of a diagnoses only increased by fractions of one percent. Therefore, the verdict was no cause for hysteria, especially when taking into account the other problems baked into the report.
It’s evident there is an active effort to demonize moderate alcohol consumption, even though compelling evidence supporting the presumption is lacking.
This isn’t to say regularly drinking to excess shouldn’t be cause for concern. Consuming seven, eight, nine drinks a day is clearly associated with adverse health effects. But comparing the impacts of moderate consumption to that of heavy drinking or smoking is ridiculous. In fact, mountains of less dubious prior research conducted over decades suggests just the opposite: moderate alcohol consumption has been linked to modest health benefits.
While studies of human health should never be ignored, it’s important that the methodology be scrutinized and findings questioned. In this case, it’s clear the report’s conclusions rely on unsound science and need to be taken with a grain of salt.
Jackson Shedelbower is the communications director of the American Beverage Institute.