It’s Breast Cancer Awareness Month. Looking at media coverage of the issue, is it any wonder I’m a little nervous about my own drinking habits?
Most nights, I cook my family dinner while sipping a glass of wine — just one, maybe two. It helps me calm down after a day of writing, tweeting, meetings, running errands, fetching and carrying kids all over town. Is this a problem?
Well, if you only rely on many media sources or, God forbid, turn on one of those afternoon talk shows, like "Dr. Phil" or "The Dr. Oz Show," the answer is almost always yes — you’ve got yourself a problem, and you’re likely on a one-way train to Cancerville.
But this sort of alarmism is no longer relegated to ratings-hungry television shows and click-needy online print publications. Today, we see these sorts of hyped claims in legitimate scientific journals.
For instance, this summer — you know, when you were on the deck drinking gin and tonics and rose wine was at peak levels — the fun-stealers at the British medical journal The Lancet published a study concluding “the safest level of drinking is none.”
None. I bet those researchers are fun at parties.
Naturally, that study generated a bunch of scary headlines warning that even low levels of alcohol are dangerous.
Yet, another recent article published in the prestigious medical journal Cancers brings some relief. The authors — Samir Zakhari (full disclosure: Zakhari works for the Distilled Spirits Council of America, commonly known as DISCUS, the trade association that represents liquor companies) and Jan B. Hoek, professor and vice chair for research and the vice chair for technology, innovation, and infrastructure at Thomas Jefferson University — examine the evidence used by The Lancet to suggest moderate alcohol consumption is a causal factor in breast cancer. They make an incredibly strong case that causal links between alcohol and breast cancer fold when held up to real scrutiny.
The researchers first examined many of the studies that have suggested a causal relationship between cancer and alcohol consumption and found that instead of a causal relationship (meaning this behavior leads directly to this disease), the studies mostly found a correlation (i.e., an association).
This is a critical detail. One of the reasons correlations don’t mean causation is that researchers often can’t account for the numerous confounding factors (diet, exercise level, genetics, age, environmental factors) that can also affect breast cancer development. In other words, someone might develop cancer because of alcohol use, or they might develop cancer from a bad diet or because they are genetically predisposed to cancer. It wouldn't be surprising that people who abstain entirely from alcohol also engage in other healthy behaviors like eating healthier or exercising more, both of which could explain the correlation as much as the lack of alcohol.
These kinds of studies, the ones that look for correlations, are the only type of medical research that can be done. While randomized control studies are considered the gold standard for clinical trials, one can’t force-feed humans alcohol while simultaneously controlling for other factors (limiting their diet, controlling what they come in contact with) to isolate alcohol's impact and see which person ends up with cancer.
Instead, researchers must rely on self-reported alcohol consumption estimates. These are known to be unreliable since few admit to drinking large quantities of alcohol. This is also true in nutrition science, where people don’t really want to admit they ate a whole pizza for dinner or had a triple scoop of chocolate ice cream for dessert. Instead, it's common for test subjects to fib and say they ate a “slice” of pizza along with a make-believe healthy salad, and of course, there was no dessert.
When it comes to alcohol consumption, American consumers fess up to buying half of the alcohol that is sold. So, what happened to that other half? Well, it was likely consumed, but no one needs to know about it, right?
Thus, it is reasonable to assume that many of the subjects involved in the breast cancer studies underreported their actual consumption. Zakhari and Hoek also note that, while many studies do show an association, many do not. Yet, like most good news stories, those rarely get published or receive the same media attention.
In their conclusion, Zakhari and Hoek remind us: “Alcohol has a social function that is important in many people’s lives. For the vast majority of drinkers, this social function is associated with occasional or moderate drinking. The relative risk of negative consequences, including the relative risk of developing breast cancer, is therefore an issue that has to be weighed against these positives.”
That’s a super-wonky way of saying that social drinking can be fun, and happiness can also result in good health outcomes. Of course, everyone knows that alcohol should be consumed in moderation. But, so should feeling guilty about an occasional indulgence. My advice: Enjoy your moderate drinking, and take these studies with a pinch of that margarita salt.