Health activists have waged a decade-long war on sodium, citing its role in high blood pressure and cardiovascular risks. They've urged consumers to avoid foods that have high sodium content.
International researchers have produced a study that takes a contrary view. Yes, too much sodium is harmful to people with high blood pressure, but they maintain that a low-sodium diet for everyone else is not only not beneficial, but may be harmful, increasing cardiovascular risk and even death.
The study, which may prove to be controversial, included more than 130,000 people from 49 countries. It was led by researchers at McMaster University and Hamilton Health Sciences, in Canada. The researchers focused on the relationship between sodium consumption and death, heart disease, and stroke.
What made the study different was the separation of the subjects into those with high blood pressure and those with a normal blood pressure reading.
The results found that subjects who had a reduced sodium consumption level were more likely to have suffered a heart attack, stroke, or death.
“These are extremely important findings for those who are suffering from high blood pressure,” said lead author Andrew Mente. “While our data highlights the importance of reducing high salt intake in people with hypertension, it does not support reducing salt intake to low levels.”
The take-away from the study, Mente says, is a low-sodium diet is best used for people with high blood pressure, but not the public in general. This conflicts with current medical conventional wisdom.
The Mayo Clinic staff notes that Dietary Guidelines for Americans recommends limiting sodium to less than 2,300 mg a day. But the staff says “less is usually better,” especially for consumers who are have a sodium sensitivity.
“If you aren't sure how much sodium your diet should include, talk to your doctor or dietitian,” the staff says on the Mayo Clinic website.
Without mentioning the Canadian study, the American Heart Association (AMA) has underscored its belief that all people should reduce sodium consumption. It says its lifestyle guidelines on sodium reduction were based on more than 30 scientific studies.
The organization stands behind a 2014 consensus statement among scientists that concluded “population-wide reduction of sodium intake is an integral approach to reducing cardiovascular disease events and mortality in the United States.”
But the Canadian researchers say their findings are conclusive, showing that risks associated with low-sodium intake, which they define as less than three grams per day, are consistent whether or not someone has high blood pressure.
They state that there is a limit below which sodium intake may be unsafe and the risk associated with high sodium consumption appears to only affect those with hypertension.