New study not quite worth its salt

Is it really okay to use the salt shaker again? At first glance, a new report might have consumers passing up anything low-sodium and asking for extra salt: The Cochrane Library has published a systematic review of seven studies that, to everyone s surprise, suggests that moderate reductions in salt intake have no discernible effect on one s likelihood of developing cardiovascular disease.

But hold on. The authors of the study, led by Professor Rod Taylor from Peninsula College of Medicine and Dentistry in the UK, caution that there was not enough information to understand the effect of these changes in salt intake on deaths or cardiovascular disease. As the American Heart Association has been quick to point out, the studies reviewed have several flaws. Most notably, although the review found that reduced sodium intake did lead to a small reduction in blood pressure after six months, none of the studies followed patients for longer than six years, which is simply not long enough to draw definitive conclusions; high blood pressure takes years to damage blood vessels. Also, the groups studied were comprised largely of middle-aged whites, while rates of hypertension and heart disease are highest in blacks.

Perhaps the best thing about this study is that it s a good way to educate people including the media about how not to leap to conclusions, says ACSH s Dr. Gilbert Ross. There needs to be a longer term, controlled study of how sodium intake affects blood pressure, and how such a significant dietary manipulation affects heart outcomes.