A large, international new study suggests the health risks associated with sodium consumption may be more limited than doctors widely believe, according to Science Daily. The Canadian researchers behind the study looked at data from 94,000 individuals, between the ages of 35 and 70, over an average period of eight years. It included data from 18 countries around the world. They found that under a high limit of five grams, there is “no convincing evidence” for an increased risk of heart disease or stroke.
Currently, guidelines from the World Health Organization recommend limiting sodium intake to no more than two grams a day, due to its connection high blood pressure and strokes. Generally, it’s believed that salt consumption leads more water to be retained in the body, putting more pressure on the heart. The American Heart Association recommends even less, a limit of just 1.5 grams of sodium for those at risk of heart disease.
“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,” according to Andrew Mente, first author of the new study, by researchers with the Population Health Research Institute (PHRI) of McMaster University and Hamilton Health Sciences.
Researchers from around the world also provided data for the study, which was published Thursday in The Lancet.
“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,” he added.
They also found that heart disease and death were reduced in countries and communities with diets higher in potassium, with beans, nuts, fruits and vegetables as key sources.
However, the study has been widely criticized for its approach, using a single urine sample for individuals, instead of tracking sodium levels over 24 hours, and for including already ill participants in the research.
According to Martin O’Donnell, a co-author of the study, previous research on the health effects of sodium often relied on data from the individual level — whereas the new study uses community-level information.
“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,” says O’Donnell.