China is the only country in their study where 80 per cent of communities have a sodium intake of more than five grams a day.
In the other countries, the majority of the communities had an average sodium consumption of 3 to 5 grams a day (equivalent to 1.5 to 2.5 teaspoons of salt).
“The World Health Organization recommends consumption of less than two grams of sodium that’s one teaspoon of salt a day as a preventative measure against cardiovascular disease, but there is little evidence in terms of improved health outcomes that individuals ever achieve at such a low level,”
said Andrew Mente, first author of the study and a PHRI researcher.
He added that the American Heart Association recommends even less 1.5 grams of sodium a day for individuals at risk of heart disease.
“Only in the communities with the most sodium intake those over five grams a day of sodium which is mainly in China, did we find a direct link between sodium intake and major cardiovascular events like heart attack and stroke.
“In communities that consumed less than five grams of sodium a day, the opposite was the case. Sodium consumption was inversely associated with myocardial infarction or heart attacks and total mortality, and no increase in stroke.”
“We found all major cardiovascular problems, including death, decreased in communities and countries where there is an increased consumption of potassium which is found in foods such as fruits, vegetables, dairy foods, potatoes and nuts and beans.”
The information for the research article came from the ongoing, international Prospective Urban Rural Epidemiology (PURE) study run by the PHRI. Mente is also an associate professor of the Department of Health Research Methods, Evidence and Impact at McMaster University.
Most previous studies relating sodium intake to heart disease and stroke were based on individual-level information, said Martin O’Donnell, co-author of the report, a PHRI researcher and an associate clinical professor of medicine at McMaster.
“Public health strategies should be based on best evidence. Our findings demonstrate that community-level interventions to reduce sodium intake should target communities with high sodium consumption, and should be embedded within approaches to improve overall dietary quality.
“There is no convincing evidence that people with moderate or average sodium intake need to reduce their sodium intake for prevention of heart disease and stroke,”
Besides Canada, this research involved individual and community information from the countries of Argentina, Bangladesh, Brazil, Chile, China, Columbia, India, Iran, Malaysia, occupied Palestinian territory, Pakistan, Philippines, Poland, Saudi Arabia, South Africa, Sweden, Tanzania, Turkey, United Arab Emirates, and Zimbabwe.