Flying in the face of the USDA’s extremely stringent recommendations for population-wide sodium consumption, a recent study reports that low sodium consumption may actually increase a person’s cardiovascular risk.
In a study published in today’s Journal of the American Medical Association, Dr. Martin J. O’Donnell from the Population Health Research Institute in Ontario and colleagues measured levels of sodium in the urine and tracked cardiovascular events over an average of four and a half years of follow-up among almost 30,000 patients with cardiovascular disease or diabetes. (Sodium excretion is a good proxy for assessing sodium intake.) As expected, those patients who had a particularly high level of sodium intake (over 7,000 mg per day) had a significantly increased cardiovascular risk. Yet, what was most surprising was that those patients who consumed less than 3,000 mg of sodium per day were also at a significantly increased risk of cardiovascular events.
Considering that the official U.S. dietary guidelines are even more restrictive than this — 2,300 mg of sodium per day for the average person, and only 1,500 mg per day for people over 51, African Americans, or those with other cardiovascular risk factors — this finding is cause for concern. Since the average American consumes much greater amounts of sodium daily — 3,400 mg on average — ACSH's Dr. Ruth Kava disagrees with recommendations that promote such extreme reductions in sodium intake. “I could see why such advisories may be beneficial to certain categories of patients, such as those with congestive heart failure or kidney failure,” she says, “But the average person will not be able to sustain such levels, nor would it necessarily be healthy for them to try.”
As ACSH's Dr. Gilbert Ross comments, “People — including us here at ACSH — who have long been concerned about the wisdom of these overly stringent recommendations now seem to have been correct: Too little sodium, even a quantity consistent with the official advisories, might actually increase heart risk. As we have said, advising such drastic reductions in sodium consumption is like a vast, uncontrolled experiment on the American population, with, as this study demonstrates, potentially harmful consequences.”
