We all know canned tuna is a quick, affordable, and protein-packed meal option. But what if I told you that your favorite tuna sandwich could be slowly harming your health? Yes, that humble can of tuna sitting in your pantry might be hiding a dangerous secret: mercury.
Mercury is a toxic heavy metal that can wreak havoc on your brain and nervous system, especially if consumed in excess. And here’s the kicker—not all tuna is created equal. Some types of tuna are far more contaminated with mercury than others, and if you’re not paying attention, you could be unknowingly filling your body with this dangerous toxin.
In this post, we’ll dive deep into the world of canned tuna, uncovering the truth about mercury, the biggest mistakes people make when buying and eating tuna, and how you can enjoy this nutritious food without putting your health at risk. Let’s get started!
What is Mercury, and Why Should You Care?
Mercury is a naturally occurring heavy metal found in the Earth’s crust. However, thanks to industrial activities like coal burning and mining, large amounts of mercury have been released into the environment. This mercury eventually finds its way into rivers, lakes, and oceans, where it undergoes a dangerous transformation.
In water, mercury is converted into methylmercury, a highly toxic form that accumulates in the bodies of fish. Small fish absorb methylmercury from the water, and when larger fish like tuna eat those smaller fish, the mercury builds up in their bodies over time. This process is called bioaccumulation, and it’s why large predatory fish like tuna end up with such high levels of mercury.
When we eat tuna, we’re also consuming that accumulated mercury. Over time, this can lead to serious health issues, especially for vulnerable groups like pregnant women, young children, and people with nervous or cardiovascular system concerns.
The #1 Mistake Everyone Makes with Canned Tuna
The biggest mistake people make when buying canned tuna? Not knowing the difference between tuna species. Not all tuna is the same, and the type of tuna you choose can have a huge impact on your mercury exposure.
Here’s a breakdown of the three main types of tuna you’ll find on supermarket shelves:
- Skipjack Tuna: This is the smallest and most commonly consumed tuna. It’s labeled simply as “tuna” on most cans and has the lowest mercury levels (0.12 parts per million). Skipjack is the safest choice for regular consumption.
- Yellowfin Tuna: Larger than skipjack, yellowfin tuna lives longer (7-10 years) and has almost three times the mercury levels (0.35 parts per million). It’s still safe to eat but should be consumed in moderation.
- Albacore Tuna: This is the big one—literally. Albacore tuna contains the highest levels of mercury (up to 0.50 parts per million). The U.S. Environmental Protection Agency (EPA) and Food and Drug Administration (FDA) recommend significantly limiting your consumption of albacore tuna.
Pro Tip: Always check the label to see which type of tuna you’re buying. If it just says “tuna,” it’s likely skipjack, the safest option. But if it’s labeled “light tuna” or “yellowfin,” be prepared for higher mercury levels.
3 More Common Mistakes When Eating Canned Tuna
- Not Reading Labels Carefully: Many people grab a can of tuna without checking the label. But this small oversight can have a big impact on your health. Look for cans that specify the type of tuna, and if you’re unsure, do a quick search on the manufacturer’s website. Some brands are more transparent than others.
- Overdoing It: Canned tuna is convenient, but eating too much can lead to mercury buildup in your body. The U.S. dietary guidelines recommend eating about 8 ounces (227 grams) of seafood per week, including tuna. To reduce your mercury exposure, rotate tuna with other low-mercury fish like salmon, sardines, mackerel, and trout.
- Not Draining the Tuna Properly: Whether your tuna is packed in water or oil, draining it properly is crucial. If you don’t, your mayo will get watery, and your salad will turn into soup. Use a fine mesh strainer or the can’s lid to press out every last drop of liquid. This simple step makes a huge difference in the final texture of your dish.
Tuna in Water vs. Tuna in Oil: Which is Better?
Here’s where things get interesting. Fresh tuna is always the best option, but let’s face it—canned tuna is a lifesaver on busy days. So, should you go for tuna packed in water or oil?
- Tuna in Oil: Heavy metals like mercury are lipophilic, meaning they’re attracted to fat. When you drain the oil from tuna, you’re also discarding a good portion of those unwanted contaminants. Plus, tuna in oil has higher amounts of omega-3s and vitamin D. However, it’s also higher in calories.
- Tuna in Water: While it’s lower in calories, tuna packed in water retains more mercury because there’s no oil to trap the metals. So, if you’re looking to reduce mercury exposure, well-drained tuna in oil might be the smarter choice.
How to Enjoy Tuna Safely
Tuna is an incredibly nutritious food, packed with protein, omega-3s, and essential vitamins. The goal isn’t to stop eating it—it’s to make smarter choices. Here’s how:
- Choose Skipjack Tuna: Opt for cans labeled simply as “tuna,” which are usually skipjack, the lowest-mercury option.
- Read Labels Carefully: Always check the type of tuna and the brand’s transparency about mercury levels.
- Rotate with Other Fish: Mix tuna with other low-mercury fish like salmon, sardines, and trout.
- Watch Your Portions: Stick to the recommended 8 ounces of seafood per week to keep mercury exposure in check.
Related: Stop Making These 13 Common Health Mistakes, Especially After 50
Final Thoughts
Canned tuna doesn’t have to be a health hazard. By understanding the risks and making informed choices, you can enjoy this convenient and nutritious food without worrying about mercury. Remember, it’s all about balance and awareness.
So, the next time you’re at the supermarket, take a moment to check the label and choose wisely. Your brain—and your body—will thank you.