Tuna tends to live a double life in the wellness world. One minute it’s praised as a lean protein powerhouse loaded with omega-3s, and the next it’s being dragged for mercury like it personally polluted the ocean. So which is it?
The truth, as usual, isn’t as simple as it sounds. Once you understand why mercury shows up in tuna—and when tuna does and does not make sense—you can make informed, confident choices without throwing a nutrient-dense food under the boat.
Mercury doesn’t magically appear inside tuna, and it isn’t unique to tuna either. Mercury enters the ocean through industrial pollution—coal plants, mining runoff, waste incineration—and once it’s there, it doesn’t discriminate. In seawater, it becomes methylmercury, the form that marine life absorbs.
What often gets missed is that fish are exposed to mercury both from the outside and the inside. Tuna absorb mercury externally through their gills and skin as they swim and breathe in contaminated water, and internally by eating smaller fish that already contain mercury. In other words, they’re hit outside-in and inside-out.
Because mercury exists in the water itself, this exposure isn’t limited to tuna alone. It affects marine life across the ecosystem—fish of all kinds, shellfish like crab, lobster, shrimp, and scallops, and yes, even beloved salmon. Tuna draw more attention simply because they sit higher on the food chain and tend to live longer, which allows mercury to accumulate more noticeably over time. Smaller fish absorb less. Bigger fish absorb more, both from their environment and their diet.
So this isn’t a “tuna is toxic” issue. It’s an ocean pollution issue. Sadly, they’re swimming in the same environment we’ve collectively impacted. The fish aren’t the villains here. They’re the messengers.
If mercury were the only thing tuna brought to the table, this wouldn’t be much of a conversation. Nutritionally, though, tuna earns its place. When sourced well, it delivers a dense package of nutrients that support the brain, nervous system, cardiovascular system, and overall metabolic health—without requiring a supplement aisle.
Tuna provides omega-3 fatty acids EPA and DHA, the forms your body actually uses. These support brain health, cognition, mood, inflammation balance, and heart health, and tuna delivers them efficiently without capsules or fillers. It’s also a strong source of vitamin B12, which supports energy production, nervous system function, and red blood cell formation. Low B12 can show up as fatigue, brain fog, mood changes, or numbness—none of which help anyone feel their best.
Selenium is another key nutrient found in tuna and deserves special mention. It supports antioxidant defense, thyroid health, and immune function, and it also helps bind mercury, reducing its toxicity in the body. This doesn’t cancel mercury out, but it does help explain why the conversation isn’t black and white. Add in niacin for metabolic and cardiovascular support, phosphorus for bones and cellular energy, and lean, complete protein for satiety, muscle maintenance, and blood sugar stability, and it becomes clear why tuna has remained a staple for so long.
That said, context matters. If you’re in a phase where you’re actively trying to detox heavy metals and lighten your body’s load, tuna probably isn’t your go-to food right then. This article is about everyday eating outside of that phase—when occasional, well-sourced tuna can fit without creating unnecessary stress on the body.
It’s also important to zoom out and recognize that this conversation isn’t unique to tuna. The same principle applies to all meat, seafood, and really everything we eat. How food is raised, caught, processed, and packaged determines whether it supports the body or quietly works against it. Tuna simply makes this reality more visible because mercury gets so much attention.
Here’s the good news: when companies practice safer, more responsible sourcing, they usually tell you. Sustainable fishing methods, mercury testing, and responsible packaging cost more, and brands that invest in those practices don’t keep them quiet. They put that information right on the label, and yes, you’ll usually pay more for it.
That higher price reflects slower, more intentional fishing methods like pole-caught tuna caught one fish at a time, less bycatch—meaning fewer dolphins, sea turtles, sharks, and other beloved ocean animals harmed unintentionally—smaller, more carefully selected fish, mercury testing, and better packaging and ingredient choices. When tuna is cheap, vague, and silent about its sourcing, there’s a reason for that.
Labels that clearly explain how the fish was caught, what species it is, whether it’s been tested, and how it’s packaged are doing you a favor. Transparency is rarely accidental. On the flip side, labels that simply say “tuna” with no species listed, offer no information about how the fish was caught or tested, rely on low-quality vegetable, soybean, or seed oils, or are priced unusually low with no explanation deserve a little skepticism. As you’ve learned before, not all oils are created equal, and if a brand cuts corners on the oil, it often signals shortcuts elsewhere too.
If you’re having trouble finding canned tuna that meets these standards at your usual grocery store, it often helps to change the store rather than the food. Places like Natural Grocers, Whole Foods, Sprouts, or your local food co-op tend to curate brands with cleaner sourcing, better oils, and more transparency, making it easier to choose without playing label detective.
So should you eat tuna or not? Outside of a heavy-metal detox phase, tuna doesn’t need to be a daily food, but it also doesn’t need to be exiled. Rotating seafood, choosing wild and pole-caught options, avoiding large predatory fish as staples, and paying attention to sourcing transparency are all reasonable, balanced choices.
Once you’ve found a tuna you trust, the next step is simply enjoying it. That’s where simple, real-food recipes come in—like my Better Than Mom’s Tuna Salad, which turns thoughtfully sourced tuna into an easy, satisfying meal without overthinking it. This approach—learning, choosing with intention, and then actually enjoying your food—is at the heart my book, The Awakened Body. It’s not about chasing perfection or avoiding foods out of fear. It’s about listening to your body, understanding the bigger picture, and making choices that support both your health and your values.
Tuna doesn’t exist in a vacuum. Like all food, it tells a story about where it came from and how it was produced. When you know that story, you can decide when tuna makes sense, when it doesn’t, and how to choose it in a way that aligns with both your health and your values.
Eat it sometimes. Source it well. Rotate intelligently. Respect timing.
That’s how you support your body and the planet—without losing good food in the process.
Click HERE to learn more about The Awakened Body.
Click HERE for my Better than Mom’s Tuna recipe.