A couple of weeks ago, Lynne Murray blogged for us about the “faith sentence,” that little coda at the end of a journalism piece that repeats common wisdom, even if it’s completely contradictory to the facts in the article. This week’s faith sentence, from this article, is “There is no level of alcohol consumption that can be considered safe.”
Unfortunately, the entire study is available only by subscription, so we can’t quote from it directly. Perhaps more unfortunately, we can’t really blame journalists or the media for the message that’s getting out: the study’s abstract repeats the faith sentence.
I trust Sandy Szwarc at Junk Food Science, and she reports on it extensively.
The actual incidents of all cancers was 5.7% among the nondrinkers. The cancer incidents were lower among the women drinking up to 15 drinks a week: 5.2% among those consuming ≤2 drinks/week; 5.2% of those drinking 3-6 drinks/week; and 5.3% among those drinking 7-14 drinks a week.
In other words, women drinking as many as two drinks a day were associated with lower actual incidences of all cancers compared with the nondrinkers.. This is the exact opposite of what has been widely reported. Although the differences in actual cancer risks were tiny, nondrinking was associated with a 0.4% higher incidence of all cancers compared to women drinking two drinks a day.
The incidents of all cancers among the women drinking the most alcohol (15 or more alcoholic drinks a week), who made up only 5% of the cohort, was 5.8%, nearly the same as the nondrinkers. These women differed from the other groups of drinkers in other ways, such as being more likely to smoke, to exercise strenuously, have used oral contraceptives and be currently using hormone replacement therapy, have higher socioeconomic status, and lower BMIs. So considerable potential confounding factors are involved in trying to interpret this correlation.
Sandy has more to say, of course, including the salient facts that the numbers were not statistically “tenable” and that everything is based on secondary data from the Million Women Study, and the only thing it could do, even if it had produced statistically significant numbers, would be to show a correlation without a causation.
This kind of science, of course, is familiar to readers of Body Impolitic, Junk Food Science, or a legion of other sources that pay attention to science reporting. In this case, there’s another factor.
The researchers were working with the Million Women Study data, not interviewing new people, so by definition all of their subjects were women. Therefore, when the alcohol study is reported, the headlines say:
“Even Small Amounts of Alcohol Increase a Woman’s Risk of Cancer” or “Daily Drink for Middle-Aged Women Cancer Risk.”
Given the flaws in the study abstract, this is accurate reporting. The study did concentrate on women and the researchers did state that the risk is important. At the same time, listen for the implication: Drinking is fine for men. Especially in this period where there’s so much pressure to separate out the physiology, neurochemistry, and sociology of men and women, labeling something as “about women,” even if that label is factually accurate, carries a connotation of “not about men.”
Looking at various articles reporting the study, most of them simply don’t mention men. The one that does says, more than halfway through the article:
“Lead author Dr Naomi Allen from the University of Oxford said her work would help the government assess whether the limits should be changed, although the study did not look at men.”
In this case, because the study’s analysis is so thoroughly flawed, the reporting does men a favor and women a profound disservice. But it could so easily cut the other way.
Thanks to Rich Dutcher for pointing it out, and to Charlie Stross for doing a lot of the legwork.