In previous posts, I’ve explored the accuracy of protein and sodium on Canadian food labels. Today, I’m excited to dive into potassium!
I’m especially excited about this topic because:
- Potassium is my favorite mineral.
- My colleagues and I recently published a paper on this exact question.
The full article is available open access here: The Accuracy of Potassium Content on Food Labels in Canada.
What Did We Do?
Back in 2023, inspired by a previous study, I submitted a Freedom of Information request to the Canadian Food Inspection Agency (CFIA) for all their data on potassium content in foods.
After some back and forth, I finally received a disc in the mail containing a massive PDF of the data. With the help of a student, we converted this PDF into an Excel file that we could actually work with—and explore the numbers.
What Did We Find?
Main Findings:
- Limited sampling: Very few foods were tested, and much of it focused on niche products like vegan cheese.
- Label accuracy: Some foods had accurate potassium content, but many either under-reported or over-reported their potassium levels—sometimes by a large margin.
- Tendency to under-report: Most products were more likely to under-report potassium than over-report. This makes sense because Canadian labeling laws allow some under-reporting, but over-reporting would make a product non-compliant.
What Does This Mean?
Our findings highlight two important points:
- Very little testing has been done on potassium content in Canadian foods—far less than sodium.
- Food labels are often inaccurate, with a tendency to under-report potassium.
Implications for Clinical Practice
For clinicians advising patients on low-potassium diets, it’s important to know that:
- Products labeled low in potassium may actually contain more potassium than stated and could be unsafe for patients who need to limit intake.
- Products labeled high in potassium are more likely to truly be high in potassium, which is important for diet planning.
In short, Canadian food labels cannot always be relied on to precisely identify high- or low-potassium foods. Clinicians should use caution and, when possible, consult lab-tested nutrient databases or guides.
Take-Home Message
Potassium content on Canadian food labels is often inaccurate, mostly under-reported, and only sparsely tested. For people managing potassium intake—especially those with kidney disease—labels should be used with caution.
