HRT: Model for dietary salt?
Anti-salt zealots display a religious fervor for their cause, trampling scientists who remind them that actual evidence of a health benefit exists only in the end product of elaborate mathematical models extrapolating only blood pressure effects (and even those are often shrouded in withheld statistics preventing replication). There's an arrogance to their advocacy. And a familiarity.
Investigative science reporter Gary Taubes published the lead story in the New York Times Magazine on September 16, asking "Do We Really Know What Makes Us Healthy?" It's the tragic story of well-intended, plausible advocacy of hormone replacement therapy (HRT) for post-menopausal women. The bright promise, the powerful claims and the glittering possibilities all came crashing down a few years ago when it was found that for many if not most of the target audience, the "cure" was killing far more than it was helping.
Taubes called for more "self-doubt" and recommital to the discipline of scientific investigation, foregoing the passion of the righteous objective for the surer cycle of scientific advance -- proposing hypotheses, testing them to discard most of them and then repeating the cycle to refine those who pass muster.
As he pointed out:
While it is easy to find authority figures in medicine and public health who will argue that today's version of H.R.T. wisdom is assuredly the correct one, it's equally easy to find authorities who will say that surely we don't know. The one thing on which they will all agree is that the kind of experimental trial necessary to determine the truth would be excessively expensive and time-consuming and so will almost assuredly never happen. Meanwhile, the question of how many women may have died prematurely or suffered strokes or breast cancer because they were taking a pill that their physicians had prescribed to protect them against heart disease lingers unanswered. A reasonable estimate would be tens of thousands.
In conclusion, Taubes cautions:
All of this suggests that the best advice is to keep in mind the law of unintended consequences. The reason clinicians test drugs with randomized trials is to establish whether the hoped-for benefits are real and, if so, whether there are unforeseen side effects that may outweigh the benefits. If the implication of an epidemiologist's study is that some drug or diet will bring us improved prosperity and health, then wonder about the unforeseen consequences. In these cases, it's never a bad idea to remain skeptical until somebody spends the time and the money to do a randomized trial and, contrary to much of the history of the endeavor to date, fails to refute it.
