Why Some People Should Avoid Eating Walmart's Canned Tuna

Many retailers have store brands; Walmart is no exception. Walk into any Walmart and you'll see "Great Value" products lining the shelves, including canned tuna. However, though economically priced Great Value canned tuna may tempt you financially, you may need to reconsider purchasing it if you have food sensitivities or allergies.

This problem isn't obvious. You could easily assume that Great Value canned tuna is like any canned tuna. After all, when you examine the Great Value chunk light tuna ingredients listing, you'll see only four items: tuna, water, vegetable broth, and salt. None of these are likely to raise your eyebrows. But the cautionary note under the ingredients is where you might start to get concerned.

Below the ingredients is a warning that the can of tuna could contain trace amounts of several unexpected foods, including eggs, milk, soy, wheat, sesame, or coconut. Consequently, if you're avoiding any of those items for health or personal reasons, you may want to use caution — or switch to a different brand of tuna.

Maybe you're not worried about possibly ingesting a tiny amount of gluten or dairy, and that's fine. But for some people, accidentally consuming even miniscule portions of certain foods can be uncomfortable at best and dangerous at worst.

Let's look at what can happen if someone with celiac disease eats food with wheat. According to the Celiac Disease Foundation, ingesting just a bit of a gluten-filled food such as wheat could contribute to gastrointestinal damage. In other words, the long-term results of consistent wheat exposure (even at very small levels) could cause lasting challenges.

What about a sesame intolerance? Individuals with sesame allergies may exhibit some severe symptoms if they eat products with sesame in them. As WebMD explains, anaphylaxis can even occur in some people who are exposed to sesame. And sesame allergy reactions aren't always instantaneous; they could come hours after ingesting the product that contained the allergen.

To be fair, just because Great Value canned tuna lists a cross-contamination warning doesn't necessarily mean that any cross-contamination has occurred. Nonetheless, if you're conscientious about knowing exactly what you're putting into your body and you're at least sensitive to any of the possible contaminants, you may want to bypass Walmart's store tuna and reach for another brand. Many other brands of canned tuna don't have the same kinds of warning as Walmart's canned tuna, although they may be priced a little higher. 

As a parting note, you should be aware that all canned tuna is likely to contain some mercury, which may be something to keep in mind if you're a regular tuna eater. Fortunately, you can lower your risk of mercury exposure by carefully selecting the canned tuna you buy based on the type of tuna used during the manufacturing process.

A Consumer Reports investigation showed that mercury content can vary greatly between different varieties of tuna, and canned tuna brands will typically label which type of tuna their products contain. (For the record, Walmart's canned tuna contains skipjack tuna.) Per the article, light tuna (like skipjack) tends to have lower levels of mercury than bigeye tuna or albacore tuna.