In a world with constantly changing nutritional guidelines (eggs are bad for you; no, they're good for you!), one food has seemed to be consistently maligned: salt. But a new, and highly contested, study finds that low-salt diets do not prevent high blood pressure—and actually increase the risk of death from heart attack or stroke. But CDC officials, in a rare move, criticized the study as flawed: It's too small, used subjects that were too young, and contradicts a body of evidence showing that high sodium consumption is dangerous. Supporters, however, claim that other studies have found adverse effects from low-sodium diets.
The observational study, published today in the Journal of the American Medical Association, is considered suggestive rather than conclusive. It followed 3,681 middle-aged Europeans without high blood pressure or cardiovascular disease, and found that over an average of 7.9 years, those who ate less salt were more likely to die of heart disease. Meanwhile, those who ate more salt were no more likely to develop hypertension. But questions have arisen over whether the subjects truly provided all their urine for sodium measurement, among other things. “At the moment," a CDC official tells the New York Times, "this study might need to be taken with a grain of salt." Pun intended, we assume.