Does the amount of potassium on the label include naturally occurring and additive amounts?

Mallory from Nova Scotia asked me: “A colleague and I were wondering if you know if products in Canada are required to include the amount of potassium coming from potassium additives on the food label? We were wondering because patients will see products that list potassium additives in the ingredients but it’s only 70mg potassium on the label, would this 70mg include the potassium coming from the additive?”

My response

Dear Mallory,

Thanks so much for taking the time to reach out.

This is a really great question and one that I think we need to be asking more about.

First – the easy part of your question is whether or not the potassium content is the naturally occurring or additive – and the answer to this is that it should represent both amounts.  The law states that total potassium content is reported. So amounts that are both naturally occurring and from additives should be posted.

However – I think the more challenging part of your question is whether or not the amount that is posted is actually correct.  What I noticed when I did my work with the USDA Branded Foods Product Database is that often in comparable products that did or did not contain a potassium (or a phosphorus) additive the amount listed in the database/on product labels was the same.  

This made me wonder – how could the potassium (or phosphorus) content stay EXACTLY the same despite the addition of an additive.  And I think the most reasonable answer is that it couldn’t.  Unfortunately there have not been any larger, more robust studies examining the accuracy of potassium content reporting on Canadian Food Labels – but based on what I have seen I suspect that the accuracy is low. 

Check out this food label from Prego (https://www.campbellsoup.ca/product/prego-fresh-mushrooms-pasta-sauce-645-ml/):

This label states that 125mL of this product contains 0mg of potassium.

But the first ingredient is tomato paste – which according to the Canadian Nutrient file contains 1014mg of potassium per 100g.

Also, if you consider nutrient reporting for sodium, which has been done for much longer than potassium – evidence suggests that it is often under-reported as well.  So I think it is probably safe to assume that potassium is the same.

The Follow Up Question

Since the potassium content on labels is likely under-reported, would you advise patients to avoid/limit a product that has potassium additives but the label lists less than 100mg potassium (for example)? Or only if it is coming from certain additives i.e. potassium chloride, citrate, phosphate or lactate? I know we try to encourage patients to limit ultra-processed foods with K/phos additives but sometimes this isn’t realistic for patients, especially if they relying on the foodbank, etc. Do you talk to patients about looking for the specific potassium additives? I can see how that could be confusing but there are some patients/family members that this may be helpful for?

My response

Hi Mallory!

For foods with additives I recommend trying to avoid only

– potassium chloride

– potassium citrate

– potassium phosphate

– potassium lactate 

I don’t put the other additives on patients radar. I don’t think there is enough evidence yet to prove that they are associated with additional potassium.  

If it’s possible for the patient, I get them to avoid those four additives. Regardless of the amount of potassium listed on the label. I agree that this is a more advanced skill and not all my patients are able to do this. If I am not teaching my patients to do this, I will do a diet history to try to figure out where they might be getting exposed to these additives. Then offer specific suggestions of alternates. 

With regards to patients with food insecurity, I do what I can to adjust. But, I will be more likely to recommend potassium binders/medical management to control potassium. It can be really hard for these patients to lower their intake and still eat. And I always joke with my patients that not eating isn’t an option…

Hope this helps.

Sincerely,

Kelly

Do you have a question?

Send me an email at contact@kellypicard.com – I would love to hear from you!