This past week’s New York Times has been a showcase in just how little we understand how our world works and just how fluid scientific consensus can be. On June 2, in a piece entitled “Salt, We Misjudged You,” Science magazine correspondent Gary Taubes debunked the conventional wisdom that salt is bad for us:
Although researchers quietly acknowledged that the data were “inconclusive and contradictory” or “inconsistent and contradictory”… publicly, the link between salt and blood pressure was upgraded from hypothesis to fact.In the years since, the N.I.H. has spent enormous sums of money on studies to test the hypothesis, and those studies have singularly failed to make the evidence any more conclusive. Instead, the organizations advocating salt restriction today — the U.S.D.A., the Institute of Medicine, the C.D.C. and the N.I.H. — all essentially rely on the results from a 30-day trial of salt, the 2001 DASH-Sodium study. It suggested that eating significantly less salt would modestly lower blood pressure; it said nothing about whether this would reduce hypertension, prevent heart disease or lengthen life.While influential, that trial was just one of many. When researchers have looked at all the relevant trials and tried to make sense of them, they’ve continued to support Dr. Stamler’s “inconsistent and contradictory” assessment.
And that was only the first volley against popular scientific consensus. On June 6, the Times took aim at another bit of supposedly settled science: the mechanism behind morning-after birth control pills. One would think that given the popularity and notoriety of these pills, we would actually know what they do. Apparently not:
Labels inside every box of morning-after pills, drugs widely used to prevent pregnancy after sex, say they may work by blocking fertilized eggs from implanting in a woman’s uterus. Respected medical authorities, including the National Institutes of Health and the Mayo Clinic, have said the same thing on their Web sites…But an examination by The New York Times has found that the federally approved labels and medical Web sites do not reflect what the science shows. Studies have not established that emergency contraceptive pills prevent fertilized eggs from implanting in the womb, leading scientists say. Rather, the pills delay ovulation, the release of eggs from ovaries that occurs before eggs are fertilized, and some pills also thicken cervical mucus so sperm have trouble swimming.
The reporter spins this information into a piece about abortion, and hence its title “Abortion Qualms on Morning-After Pill May Be Unfounded” (as the revised scientific consensus now posits that the pills do not in fact abort fetuses, the Times seeks to argue that they ought not to trouble anti-abortion activists).But while this narrow political question may pique the tunnel-visioned Times, Via Meadia thinks it rather misses the larger point: for years, we’ve had absolutely no idea how key birth control pills work. Thus, buried in paragraph 29, we find this startling admission:
Ms. Jefferson of the F.D.A. said it was often difficult when a drug is approved, and even afterward, to pinpoint how it works.
So, to recap: salt will kill you, unless it won’t, and we don’t actually know how important drugs–like birth control–work.These stories have something in common: they involve study of a very complex system. The human body is so complicated, with so many feedback mechanisms and independent variables at work, that it is often extremely hard to answer seemingly simple questions. Simple systems are easier for scientists to analyze; complex ones are much harder.Journalists generally don’t appreciate or care about the difference. And over-eager policy jocks don’t want to take the fine points and uncertainties into account. They want action and they want it now.Before these stories appeared we had years and decades of sleek official spokespeople telling us that “science” tells us that salt is bad. New Yorkers can thank their stars that Mayor Bloomberg hadn’t gotten around to salt prohibition before the new studies appeared. It’s even possible that, a few decades hence, we’ll be reading similar pieces in the Times about how the calamitous predictions of the shrillest of climate change activists similarly “do not reflect what the science shows.”Science is science and Via Meadia has nothing but admiration for it; we like it, we find it interesting, we believe that advances in science can open the door to better lives for people around the world. But where science meets journalism and politics, funny things happen, distinctions get blurred, and the tentative findings of scientists turn into iron laws. This is almost always a cause of bad policy. Coercive social policies based on tentative analyses of complex systems are justified much more rarely than activists think.