Don't Pitch the Water Softener
Have you been worrying that your water softener is significantly increasing your risk of dying from a heart attack? I didn't think so. But just because you haven't been feeling vulnerable around your water softener doesn't mean the WHO hasn't been fretting for you.
Thanks to epidemiological studies going back a decade or more (e.g. "Magnesium and Calcium in Drinking Water and Death from Acute Myocardial Infarction in Women") a worry arose that we were killing ourselves by eliminating the minerals naturally found in most drinking water. Yet subsequent studies have failed to confirm the finding including the just published "Effect of water hardness on cardiovascular mortality: an ecological time series approach". So what gives?
Well, what gives is that most of what gets published in peer reviewed journals is probably false; and when it comes to causal inferences drawn from epidemiological studies "the apparently indiscriminate indentification of particular aspects of daily life as dangerous to health" is, as witty programmers say, a feature, not a bug.
