Thank you.
I'm representing the Canadian Society for Nutritional Sciences, which is soon to become the Canadian Nutrition Society. My training is in nutritional epidemiology, and I'm an associate professor at McGill.
Today I'd like to cover two points, from the perspective of a nutritionist and member of the Sodium Working Group. The first is that the health benefits of sodium reduction are very well established, and second, the three prongs to the Sodium Working Group program—education, sodium reduction in the food supply, and research—are all necessary components of a strong sodium reduction strategy.
The evidence that sodium leads to increases in blood pressure, a major cause of cardiovascular disease, is indisputable. Our best sources of data come from two types of studies. One is a dosing study, where different levels of sodium are given to the same person and changes in blood pressure are then monitored. The second type of study is the longer-term clinical trial, in which sodium intake is reduced in one group and not in a control group. Such studies, conducted in both patients with hypertension and in healthy subjects, have shown decreases in blood pressure among those randomized to sodium reduction programs.
However, sodium reduction is by no means the only solution to decreasing blood pressure. Weight loss and sodium reduction appear to be additive in their impact on blood pressure. Overweightness and obesity, present in 53% of Canadian adults, cannot be ignored in our messaging lest Canadians think reducing salt is the magic bullet to improving health. It's an important part of the whole problem.
Reducing sodium will require educating the public, changing the food supply, and research to monitor progress. Educational messages are important to sensitize the population to ways of reducing sodium intake. We could add advice to Canada's Food Guide on reducing sodium intake and inform health professionals and the public through many avenues as well.
Certainly some of this is currently being done. We have sodium content information on the nutrition facts labels on processed foods. However, the target on the label is not the desirable level of salt intake for the day but rather the tolerable upper level of intake. This does not follow the labelling for other nutrients wherein we use the desirable level for health as a target. We can thus mislead the public. For example, if one uses the upper limit of the standard, as is currently done, a cup of mystery cereal has 14% of the tolerable upper level amount, but it has 22% of the healthy target set by the Institute of Medicine.
With the current food supply, it is difficult to help consumers have a desirable intake of sodium without asking people to refrain from eating many of the processed foods they're used to and eating out often. This is not very doable. We need to reduce the sodium content of the commonly eaten foods.
Finally, research to monitor progress is essential, as public health interventions sometimes have unintended consequences. Consumers could start using the salt shaker more if we make certain foods less palatable. The best way to measure progress in sodium reduction is through measuring urinary sodium in a sample of Canadians, as this reflects sodium intake over time. Measuring diet is fraught with the difficulties of measuring salt that is added to foods with a shaker and the changing content of sodium in foods.
In closing, both broad-based education on healthy eating and offering Canadians a wide choice of healthy processed foods is essential to improving their health.
Thank you.