New study links low salt intake to higher risk of death
After years of being told to eat less salt to reduce the risk of heart attack and stroke, a new study suggests that too little sodium may actually pose health risks.
The study, published in the prestigious New England Journal of Medicine, tracked more than 100,000 people from 18 countries over more than three years. It found that people consuming less than 3,000mg of sodium a day had a 27% higher risk of death, heart attack or stroke than those consuming 3,000 to 6,000mg (above 6,000mg health risks did increase).
Even the lowest intake in the study is well above most health authorities' guidelines which range between 1,500 and 2,300mg a day.
The research has faced criticism from some scientists, however, for its method of estimating sodium levels from a single urine test instead of the preferred method of over 24 hours at multiple times. Salim Yusuf of McMasters University in Ontario, senior author of two papers on the new study, said that was impractical in such a big group.
The study also found:
- Sodium levels generally correlate with the risk of high blood pressure. But this link is strongest when sodium intake is high and not 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 3,000mg to 6,000mg of sodium a day had the lowest risk of heart problems or death from any cause. More or less sodium raised risk.