Have you been flossing your teeth lately? I know I have. Dentists have told us for about a century that good dental care requires the use of dental floss, and I have been diligent (well, not for a century, of course).

Not only so, I’ve often reminded my patients in the ER that they should do the same. After all, it was a recommendation based on sound science.

Or was it? Turns out there was never any solid research that indicated a health benefit for flossing. The studies were small and short in duration. Some were designed by the companies that made floss. (See Associated Press news story at http://goo.gl/cNz5KT.)

Mind you, it seemed (and continues to seem) intuitive. Get the stuff out from between your teeth and you will probably get fewer cavities — and better breath. Sure, it sometimes stirs up oral bacteria that can then go through your bloodstream to cause infections of your heart valves. Nevertheless, it kind of makes sense.

Of course, it also seemed rational that sun exposure, which is known to cause cancer, should be reduced. For a long time, physicians seemed to believe that vitamin D production was about the only healthy thing the sun did for us. However, there are some suggestions that the health benefits of sun exposure actually outweigh the cancer risks (possibly because sun exposure seems to activate certain nitrogen-containing compounds that lower blood pressure).

Over the years, other time-honored traditions in medicine have fallen by the wayside. We used to believe that we should drop everyone’s blood pressure to a normal level when they were having stroke symptoms. Physicians learned, however, that the sudden reduction can, in itself, cause strokes by reducing blood flow to areas with already diminished blood supply. And in trauma, we thought we should always raise the blood pressure; but it seems that it may be better to keep the injured patient’s blood pressure a little low, so that all that red stuff doesn’t flow out quite so quickly, resulting in — you know — death.

The point I’m making is simply this: Science is awesome! But (1) not everything we do, or are told to do in the name of science, is actually well researched, and (2) honest science changes over time, revisits issues, humbly critiques itself and is willing to admit error.

It’s important that Christians pursue science honestly and celebrate scientific endeavors. But, as consumers of science, as people living in a time when science is believed to be the answer to every question or problem, it’s good to remember that in every field of human endeavor, errors occur, research is inadequate, and truth is elusive. We mustn’t ever forget that.

So, go brush your teeth — and floss; it probably won’t hurt. But never be afraid to ask about the validity of the things you’re told to do … in the name of science.