Studies Question Need to Watch Your Salt
Findings Question Current Advice on Salt continued...
“We’re not challenging the blood pressure contention here. We’re seeing it, too. We’re seeing a clear association between sodium intake and blood pressure,” says Martin O’Donnell, an associate professor at McMaster University in Canada who was an author of two of the studies.
But at moderate levels, less than 6,000 milligrams a day, the effect of salt on blood pressure appears to be small. Eating less, he says, doesn’t seem to prevent heart attacks, strokes, or deaths.
U.S. dietary guidelines recommend that most Americans limit their salt intake to 2,300 milligrams a day. People with health concerns like high blood pressure, diabetes, or kidney disease are told to get even less, about 1,500 milligrams a day.
The American Heart Association’s advice is even more conservative. They say everybody should eat less than 1,500 milligrams a day (unless they lose a lot of salt through sweat, like athletes and people who work in the heat.)
But the new studies found that very few -- less than 1% -- of people around the world are hitting those goals.
What’s more, the studies found that people with low sodium intakes appeared to be at higher risk for heart attacks, strokes, and death than people who were getting a moderate amount of salt in their diets.
Experts aren’t sure why low-salt diets may harm the heart.
“Making recommendations like this to everybody needs to be backed up by very robust data. What our data and other data are showing, consistent with the recommendation last year from the Institute of Medicine, is that there’s a lot of uncertainty,” O’Donnell says.
The 2013 report from the Institute of Medicine also concluded there wasn’t enough evidence to support lowering sodium below 2,300 milligrams per day, and experts declined to identify a “healthy” range for sodium.
“Should we be making such a sweeping recommendation at a population level where there is so much uncertainty?” O’Donnell says.
O’Donnell says there are still many other important questions to answer about sodium, like whether men and women need different amounts, and whether the climate you live in changes your body’s sodium requirements.
He says his team hopes to have answers on some of those within the next few years.
For its part, the American Heart Association sees no reason to change its advice.
“There are significant limitations here. We don’t have confidence that there really is a signal of harm with a reduction of sodium in the diet,” says Elliott Antman, MD, president of the American Heart Association.
“We are not moved by these studies with respect to our position,” Antman says. “We maintain our position that there should be a lower sodium content in the American diet.”