The Unbearable 
Lightness  
of Health Beliefs

by Dtmodttl

A paper, soon to be published in the prestigious Archives of Internal Medicine, considers whether some cancers might in fact come and go, not unlike a common cold. The associated study comprised two statistically similar groups of women in Norway.  Over a five-year period, all were screened for breast cancer. Individuals in one group underwent regular screenings, while individuals in the other group were screened only once, at the end of their part of the study. One might expect similar rates of cancer in both groups, but with earlier detection in the individuals screened regularly. However, the results were surprising. The number of cancer diagnoses was significantly higher in the group regularly tested for it. A possible conclusion might be that the testing method itself causes cancer, but the scientists found past research that suggests otherwise. They therefore began to wonder whether the cancer was in fact coming and going. (Test a group of people each week for ‘flu, from October to March, and you’ll record several cases. Test another group only once, in March, and you’ll record far fewer cases.) Ultimately, in their paper they suggest just that, while calling for further research.

It’s big news. In an Internet search, I noticed that the study was widely reported on among news organizations around the world. I personally happened to learn about the study while reading the paper over my morning tea. The findings contradict common assumptions about cancer and could have major implications on health policy and on treatments. The findings also suggest that some people diagnosed with cancer today might be getting the wrong treatment. That is an inherent downside of science-based medicine. The science advances, but it’s not complete; and, the advances sometimes contradict previous understanding. Most cancer patients are probably aware of that, but, after careful consideration, want the best available treatment —which is perfectly understandable.

Does adhering to the latest in health science research make sense all the time?  Most would say that careful consideration is always necessary, from a difficult decision about cancer treatment, to the simpler issues people face every day, such as the best exercise or what to eat. As the cancer story illustrates, scientific knowledge is often incomplete.

Unfortunately, the above point sometimes gets lost when it comes to public health policy and ‘official’ recommendations. For example, in the US and many other countries, drinking any amount of alcohol while pregnant is considered a strict ‘no-no’. In fact, in some places it’s legally enforceable. While there may be reasons for some not to drink during pregnancy, the underlying science about alcohol and pregnancy is far from complete, despite thousands of studies. Recently, in fact, yet another study about drinking during pregnancy (Oct. 30, 2008, Journal of Epidemiology) suggests it might not cause any harm at all. Expect another, future study to contradict it.

Clearly, some in the public health arena are making premature conclusions about scientific findings. Amazingly, there are others who don’t even bother with the findings. On the topic of alcohol, there was another recent study, widely reported, with the finding that alcohol might “shrink” the brain. Scanning the major news websites, I noticed that little about the study itself was reported on. Rather, comments from anti-drinking groups were featured extensively, along with quotes from police agencies and health regulators —all of them, of course, delighted by a study that would, at least on the surface, seem to validate their positions. (I noticed an article from alcohol-free Iran with the headline, “Alcohol Causes Severe Brain Damage.”)

I’d bet that many of the individuals quoted from those groups didn’t actually read the study, or even its abstract. Given the lack of detail in most of the articles, I also wonder whether the journalists themselves did their homework. What are the effects of brain shrinkage, specifically? By how much did brains shrink in the study? What were the subjects drinking? Wouldn’t Budweiser shrink the brain faster than a good brandy? Is shrinking in fact bad? Does the shrinking ever reverse, and if so how quickly? What other foods and drinks might cause brain shrinkage? Some of these critical questions probably don’t even have answers at present.

The problem goes beyond journalism. Similar questions arise with respect to the banning of trans fats, legislation that “forward thinking” governments around the world are considering. Are trans fats really such a public health issue that they need banning? Is it inconceivable that a study might come along showing that trans fats are not as unhealthy as currently thought? Don’t lawmakers at all levels of government have better things to do with their time?

Too often, real science becomes obscured from public view, overshadowed by the narrative of others, including government officials, lobbies and marketing departments. They all have their motives —votes, looking busy, quarterly earnings. Sometimes even the researchers themselves lose sight of the science, as they align themselves with commercial interests. In the US, for example, a couple of once well-regarded medical professors are being federally investigated for not disclosing large payments from pharmaceutical companies, and the validity of their research is now cast into doubt. More such cases will likely follow as investigations continue.

Forceful claims or recommendations regarding personal health are often best approached with a critical frame of mind, especially when scientific studies are cited. What is true today may likely not be true tomorrow.