The new salt controversy

An article risks misleading people about sodium intake. salt

A recent New York Times article by reporter Gina Kolata calls into question the national guidelines for daily sodium intake, citing a new Institute of Medicine report that examined consequences of sodium consumption and concluded there is insufficient evidence for the health benefits of reducing sodium below 2,300 mg. Many experts, including the American Heart Association, have suggested that all individuals should aim for the low level of 1,500 mg of sodium per day, the amount considered optimal for at-risk individuals but thought to be beneficial for all.

However, this article – in focusing on a lack of evidence for the lower-limit recommendation of 1,500 mg sodium per day – risks misleading people because it overlooks the main finding of the Institute of Medicine report, which was that the current dietary guideline recommendation of 2,300 mg of sodium per day for the general population is in fact supported by ample research. As stated in the Institute of Medicine press release, “Recent studies that examine links between sodium consumption and health outcomes support recommendations to lower sodium intake from the very high levels some Americans consume now.” The current average daily sodium intake is about 3,400 mg per day, meaning that Americans should still monitor and attempt to reduce their intake in order to achieve optimal health. The findings of the report do note potential harm from consuming too little salt, but the overarching point – which was overlooked in The New York Times article – was that studies support population-based efforts to lower excessive sodium consumption.

Dr. Frank Sacks, Professor of Cardiovascular Disease Prevention at Harvard School of Public Health, offered insight into the report itself, pointing out that the committee’s conclusions discounted effects of sodium reduction on blood pressure. Noting that direct evidence between sodium level and CVD events and mortality is limited in extent of available research studies, limited in quality, and contradictory, Dr. Sacks expressed dismay that the committee gave so much weight to such a problematical body of research, saying “Discounting the especially large blood pressure reduction going from 2,300 to 1,500 mg in prehypertensives, hypertensives, older adults and blacks who are especially vulnerable to the effects of high sodium betrays an unbalanced weighing of the evidence.” Additionally, the American Heart Association has meticulously reviewed scientific research and recommends that all Americans eat no more than 1,500 mg a day of sodium.

Dr. Walter Willett, Professor of Epidemiology and Nutrition and Chair of the Department of Nutrition at Harvard School of Public Health, also weighed in on the controversy to explain why The New York Times article should be, so to speak, taken with a grain of salt:

Kolata’s report (No Benefit Seen in Sharp Limits on Salt in Diet, NYT, May 14, 2013) of the recent Institute of Medicine review of sodium and blood pressure is highly misleading.   Kolata failed to mention that the primary conclusion of this review was that the US Dietary Guidelines goal of 2,300 mg of sodium per day is robustly supported by evidence. Because the current average intake is approximately 3,400 mg per day, current efforts to reduce sodium intake in our food supply are strongly justified.  The report did conclude that evidence to reduce sodium intake further to 1,500 mg per day is insufficient.  Although this conclusion is disputed by many, and additional research is desirable, it is not essential to resolve these disagreements until we get close to the 2,300 mg goal.  This will take years of sustained effort.

Visit The Nutrition Source’s Salt and Sodium section to learn more.