The New York Times Magazine recently ran a story by author Gary Taubes titled "Do We Really Know What Makes Us Healthy?" that served up some healthy skepticism about what investigators know and don’t know about staying healthy. The story concluded with the answer “not really,” except for the obvious, such as not smoking, limiting sun exposure, avoiding obesity, controlling blood pressure and being poor.
Taubes' focus was on the limitations and unreliability of some of the basic tools used by medical researchers, especially epidemiological (observational) investigation. He looked at why the results of studies are often misleading and why this produces confusing health advice. Epidemiological studies are an indispensable arm of research, focusing on the distribution of disease and trying to find links to lifestyle or environmental factors. Epidemiology is plagued by pitfalls, though, mostly because, unlike clinical or laboratory research, it looks at people living in the real world, without any intervention or control by the researchers. These studies usually cannot prove cause and effect, but can identify associations.
John Swartzberg, MD and chair of the editorial board of the University of California, Berkeley, Wellness Letter says, “Such a study on the connection between vegetables and prostate cancer, for example, may conclude that men who regularly eat broccoli have a lower risk of prostate cancer. But that is not the same as ‘broccoli prevents prostate cancer.’ It is fair to report that finding as ‘broccoli may prevent prostate cancer.’” Put the emphasis on may. “Vegetable eaters are usually health-conscious in other ways, which may account for the benefit. Researchers try to control for such ‘confounders’ statistically, but can’t eliminate all of them. These hidden variables can easily cloud results.”
He goes on to say, “Observational studies are good at generating hypotheses that can be tested in clinical trials. Most hypotheses turn out to be wrong, so you shouldn’t change the way you live on the basis of such observations. Still, a body of research (including basic lab studies and clinical trials), in which evidence accumulates bit by bit, can eventually uncover the truth.”
“Research into human health has made enormous strides, but only by the process of trial and error.” It’s a good idea to retain a spirit of inquiry and a healthy skepticism, and not to fall victim to cynicism when conflicting research results come out or when common wisdom is overturned.
The take-away is this:
>epidemiological studies deal with people living in the real world, a less controlled research environment (key-word may)
>clinical or laboratory trials are conducted in a controlled environment and eventually prove or disprove the hypotheses of the epidemiological studies
Also keep in mind that the media jump on every crumb in an effort to be the first to report findings, so some of their reporting may be a little premature for you to take action on.
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Disclaimer: The purpose of this weblog is not to dispense medical advice nor in any way is meant to be construed as diagnostic or prescriptive. Always check with your physician before beginning any new program or trying any of the items discussed in the posts that appear on this site.
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