A large international study questions the conventional wisdom that most people should cut back on salt, suggesting that the amount most folks consume is OK for heart health — and too little may be as bad as too much. The findings came under immediate attack by other scientists.
Limiting salt is still important for people with high blood pressure — and in fact, a second study estimates that too much sodium contributes to up to 1.65 million deaths each year. The studies both have strengths and weaknesses, and come as the U.S. government is preparing to nudge industry to trim sodium in processed and restaurant foods.
The first study’s leader, Dr. Salim Yusuf of McMaster University’s Population Health Research Institute in Hamilton, Ontario, urged keeping an open mind.
“There are those who have made a career out of promoting extreme sodium reduction that will attack us,” he said. It’s better to focus on healthy lifestyles and overall diets instead of a single element, he added.
No one should view this as permission to eat more salt, he said, adding that “most people should stay where they are.”
The studies are in today’s New England Journal of Medicine.
■Sodium levels generally correlate with the risk of high blood pressure. But this link is strongest when sodium intake is high and wasn’t seen at all when consumption is low.
■A different nutrient — potassium, found in vegetables and fruits — seems to lower blood pressure and heart risks, and offsets sodium’s effect.
■People who consume 3 to 6 grams of sodium a day (about 8 to 15 grams of salt) had the lowest risk of heart problems or death from any cause during the nearly four-year study. More or less sodium raised risk. About three-fourths of the world’s population is in the ideal range. Americans average roughly 4 grams a day.
Guidelines from various groups for heart disease prevention recommend 1.5 to 2.4 grams of sodium a day. The American Heart Association advises no more than 1.5 grams.
The study was sponsored by the McMaster institute, nonprofit and government groups and industry, but funders had no role in running it. The countries included Canada but not the United States.