Sodium levels remain unchanged or even slightly higher in most of the packaged food groups sold in Canada, say researchers, who are questioning the effectiveness of the current voluntary approach to reducing salt in our food supply.
Canadians consume more than twice the recommended adequate intake of sodium, mostly from packaged and prepared foods. Cutting sodium consumed by the population is a public health priority because too much can lead to high blood pressure, a major risk factor for stroke, heart disease and kidney disease.
The national voluntary sodium reduction strategy, introduced by Health Canada in July 2010 after two years of input from a working group made up of scientific, industry, governmental and other members, aims to reduce average sodium consumption to 2,300 milligrams per day by 2016. Most adults consume a little more than 3,000 milligrams of sodium on average each day.
One teaspoon salt of salt contains about 2,300 milligrams of sodium, according to the American Heart Association.
There are currently no federal or provincial programs to monitor sodium levels or track the food industry's progress.
To that end, researchers from the University of Toronto and University of Ontario Institute of Technology in Oshawa analyzed sodium levels from the Nutrition Facts table of about 10,000 packaged foods in 2010 and 15,000 foods in 2013.
Overall, the majority of food categories, 82 per cent, had no change in sodium between 2010 and 2013, Prof. Mary L'Abbé, chair of nutritional sciences at the University of Toronto and her co-authors report in Tuesday's issue of the journal Applied Physiology, Nutrition, and Metabolism.
"It's certainly not a stellar grade," said study co-author JoAnne Arcand, a registered dietitian and assistant professor at the University of Ontario Institute of Technology. "I would expect more."
Sodium levels went down in only 16.2 per cent of food categories, while 1.9 per cent of categories increased in sodium.
Certain food categories that are high in sodium showed very little progress, such as pantry breads and packaged deli meats, the researchers said. These foods also contribute the most sodium to Canadians' diets because they are so widely consumed.
But other countries have shown reductions over a similar time period. The study's authors highlighted how sodium in breads have been reduced by 18 per cent in Argentina and Spain as well as by 9 per cent in Australia.
After breads, processed meats are the second greatest contributor of sodium in the diet of Canadians.
Only sausages, wieners, fresh and frozen meat and poultry products had significantly lower levels of sodium in 2013. Importantly, the researchers said, the widely consumed package deli meat meat category had an "insignificant" 0.9 per cent reduction in average sodium levels. "
In Canada, some manufacturers have reformulated products, the researchers said. Ready-to-eat breakfast cereals, instant hot cereals, canned vegetables and legumes, plain chips, condiments and imitation and simulated seafood for example each reduced sodium by almost 15 per cent or more.
On the other end of the spectrum, some categories, such as soya and oriental sauces, dips and gravies showed significant increases in average sodium levels over the study period.
"What our data is showing is that Canadian consumers will need to continually actively seek out low sodium products," Arcand said.
Continued monitoring needed
Nearly 42 per cent of foods still do not meet any benchmark target, the researchers said in presenting the snapshot of the food industry's progress.
"Though some progress has been made in various sectors, this data supports the need for continued efforts by the food industry in lowering the sodium content of packaged food items and for continued monitoring," the study's authors said.
Dr. Norman Campbell of Hypertension Canada and the University of Calgary said the findings show the food industry hasn't kept pace with the voluntary standards.
"Regular monitoring would send a strong message to industry about the importance of taking action to reduce sodium, trans fats, and added sugar in packaged foods. We should not have to rely on scientists alone to undertake such a large-scale, complex analysis and publish critical data about it," Campbell said in a statement.
The food industry is committed to gradually reducing the amount of sodium in the food supply, the Food & Consumer Products of Canada, which represents companies that manufacture and distribute the vast majority of food, beverage and consumer goods found on drug and grocery store shelves, said in a statement with the Retail Council of Canada.
"We're pleased with the progress that has been made and believe that's evidence that the voluntary approach does work," Dave Wilkes, senior vice-president for grocery at the Retail Council of Canada. About 90 per cent of sales in grocery are represented by its members. "I am quite confident though that we will see further progress as we look at the more recent data."
Since sodium is a preservative, there needs to be innovation in the marketplace to ensure food safety is not compromised, Wilkes said. Gradually reducing sodium levels also helps consumers to adjust to the new taste profiles, he said.
Some samples sizes differed between 2010 and 2013 but the grocery stores samples stayed the same to continue to capture major national brands.
The minister of health's mandate letter includes the promotion of public health in part by "bringing in tougher regulations to eliminate trans fats and to reduce salt in processed foods, similar to those in the United States."
The study was funded by the Canadian Institutes for Health Research and the Canadian Stroke Network.