Public Policy and Dietary Sodium Restriction—Reply

In Reply: Dr McCarron and colleagues suggest that efforts to reduce sodium intake may not achieve their goal because sodium intake is physiologically fixed. This raises the possibility that reducing salt in prepared food might have the unintended consequence of increasing caloric consumption to maintain sodium intake. But guesswork will not determine the consequences of reducing the salt in food; only a randomized clinical trial (RCT) can do that.

The opinions of Dr Cook and colleagues, whose work has contributed substantially to understanding the relation of sodium to human biology, merit careful consideration. It is not surprising, given the mostly observational data linking sodium to human health, that interpretations and conclusions may differ. The observational follow-up of control participants in TOHP is the most rigorous of its kind and the only such study in the US population.¹ The writers note the positive relation of the sodium-potassium ratio to mortality in this study, but not the relevant null finding—no statistically significant relation of urinary sodium to mortality.