A large international study questions the conventional wisdom that most people should cut back on salt, suggesting that the amount that 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 as many as 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, Salim Yusuf of McMaster University’s Population Health Research Institute in Hamilton, Ontario, urged keeping an open mind. It’s better to focus on healthy lifestyles and overall diets instead of a single element, he said, “and that is something everyone can rally around.”
No one should view this as permission to eat more salt, Dr. Yusuf said, adding that “most people should stay where they are.”
The studies are in today’s New England Journal of Medicine.
Dr. Yusuf’s study is observational, rather than a strict experiment, and has big limitations in its methods. But its size lends strength — more than 100,000 people in 17 countries, the largest on this topic. It’s also from a general population, not just people at high risk of heart disease, as many past studies have been.
• 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. The link also is stronger as people age.
• 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.Melinda Gates - American Heart Association