November 30, 2011
The Salt of the Land
I was alerted to a new review on salt and health markers. It shows that in Caucasians, restricting salt barely has any effect. It also slightly increases cholesterol and triglycerides. Overall, they conclude that "we do not know if low salt diets improve or worsen health outcomes." Based on a session I attended at the Ancestral Health Symposium, salt restriction only helps in the subset of people who are salt-sensitive anyways.
There's also evidence that moderate consumption of salt is actually a physiological need. From a recent news article:
"Neurological research has demonstrated that animals in the laboratory "expressed an ingestive behavior designed to assure survival when threatened by sodium depletion." In other words, when salt levels fell dangerously low in animals, they sought out foods that were higher in salt until they re-established normal levels. Dr. McCarron and his colleagues posit that human beings engage in similar behaviors in order to maintain a normal sodium level.
In order to determine what that level might be, they evaluated 24-hour urinary sodium excretion from 19,151 individuals collected in 62 previously published surveys from 33 countries. They determined that adult human sodium intake ranges between 2,700 and 4,900 mg per day and concluded that "the likelihood that these diverse sources of data ... have defined the same range of sodium intake in adult humans purely by chance is exceedingly small."
They believe this data contradicts the idea that salt consumption has drastically increased in Western societies, since the range was the same across diverse cultures.
"We've been wired in our brains to consume salt within a very narrow range, to maintain our bodies' functions," said Dr. McCarron. "That range, at its very lowest limit, is 20 percent higher than what the government is telling us is the upper limit for the normal population. The average around the world ... is over 60 percent higher than what the government is telling us that we should consume."
Here's the full study(pdf).