How much salt is too much?

Two large-scale studies published this week in the New England Journal of Medicine offer conflicting evidence about salt consumption.

In a combined effort by researchers at Harvard University and Tufts University, one study assessed salt consumption around the world and found that the average global intake is 3.95 gram nearly double what the World Health Organization recommends.

Researchers believe this contributes to increasing occurrence of cardiovascular disease and a cardiologist who was not involved in the study attributes the high intake to an acquired taste for salt in American and particularly central Asian diets where daily consumption topped 5 gram.

"These new findings inform the need for strong policies to reduce dietary sodium in the United States and across the world," says lead researcher Dariush Mozaffarian, dean of the Friedman School of Nutrition Science and Policy at Tufts University.

Despite the prestige of the institutions involved, the results were criticized in an editorial, also published in the journal, for relying on assumptions.

"These provocative findings beg for a randomized, controlled outcome trial to compare reduced sodium intake with usual diet," said Dr. Suzanne Oparil in her editorial. "In the absence of such a trial, the results argue against reduction of dietary sodium as an isolated public health recommendation."

Meanwhile, another study published the same day suggests that both high and low sodium diets could be dangerous to cardiovascular health, making the case against stocking the salt shaker in the attic for the time being.

Led by Dr. Salim Yusuf of McMaster University in Ontario, Canada, the team of researchers worked with a sample of over 100,000 participants, analyzing their urine for sodium and potassium excretions in order to estimate daily consumption levels.

Their findings indicate an association between a lower risk of death and cardiovascular problems for those whose estimated daily sodium intake is between 3g and 6g.

Overall, salt is probably not an enemy but intake should be observed as the international medical community continues to evolve on the subject.