Controversial Study Finds Low-Salt Diet May Up Cardiovascular Risk
HealthDay News — Restricting dietary salt to below 3,000mg a day appears to increase the risk for cardiovascular disease similar to that of hypertension patients who eat too much salt, according to research published online May 20 in The Lancet.
Andrew Mente, PhD, an associate professor of clinical epidemiology and biostatistics at McMaster University in Hamilton, Canada, and colleagues pooled results of four studies that measured salt intake and tracked cardiovascular health. Together, the studies involved 133,118 people from 49 countries. Each study used a single, morning urine sample from each person to estimate their regular daily salt intake for extended periods of time. People with less than 3,000 mg of sodium in their urine were assigned to the low-sodium group, while 7,000 mg or more of urinary sodium was considered high-sodium.
Mente told HealthDay that his study results showed that a low-salt diet increases the risk of heart attack or stroke 26% for people without hypertension and 34% for people with hypertension. Too much dietary salt increases risk by 23% for those with hypertension; however, a diet with excess salt doesn't increase the risk at all if blood pressure is normal, according to the study authors.
The American Heart Association (AHA) is highly critical of Mente's study. The AHA says the study relies on incorrect estimates of sodium intake, and should not lead anyone to relax concerns over excess salt in the average US diet. "This is an extremely flawed analysis that doesn't provide new information, and it should not be used to guide public policy," Elliott Antman, MD, immediate past president of the AHA and an associate dean for clinical and translational research at Harvard Medical School in Boston, told HealthDay. "The American Heart Association continues to recommend less than 1,500mg of sodium per day from all sources."