You're standing at the seafood counter. The salmon looks incredible—bright, fatty, and supposedly full of those omega-3s your doctor keeps mentioning. But then you remember that headline about mercury. Or maybe you heard that microplastics are turning every filet into a science experiment. It's confusing. Honestly, the advice on how often can you eat fish changes so frequently it feels like you need a PhD in marine biology just to make dinner.
The short answer? For most people, two to three times a week is the "sweet spot" recommended by the FDA and the EPA. But that's a massive oversimplification. If you're eating sardines, you could probably eat them every single day. If you're obsessed with swordfish steaks, once a week might actually be too much. It's not just about the fish; it's about what's inside that specific fish based on where it sits in the food chain.
Why "Twice a Week" is Just the Starting Point
Most health organizations, including the American Heart Association, push for two servings of fatty fish per week. They want you to get those long-chain omega-3 fatty acids, specifically EPA and DHA. These are the heavy hitters for heart health and brain function. If you skip fish entirely, you're missing out on a protein source that is naturally low in saturated fat compared to a ribeye or even a chicken thigh.
But here is the catch.
✨ Don't miss: The Pap Smear Clamp Tool: What Actually Happens During Your Exam
Bioaccumulation is a real jerk. Small fish eat plankton. Bigger fish eat the small fish. The biggest fish—the apex predators—eat everything else. Mercury, which enters our waterways through industrial pollution and natural volcanic activity, turns into methylmercury in the water. This stuff binds to the proteins in fish muscle. It doesn't cook out. It doesn't drain away with the fat. When a tuna lives for 15 years and eats thousands of smaller fish, it stores all that mercury in its body. When you eat that tuna, you inherit its lifetime supply of heavy metals.
So, when we ask how often can you eat fish, we are really asking: "How much mercury can my body process before it becomes a problem?"
The Low-Mercury All-Stars
If you want to eat seafood almost daily, you have to stay at the bottom of the food chain. Think small. Think "ugly."
Sardines are arguably the perfect food. They are packed with calcium because you eat the tiny, softened bones, and they have some of the highest omega-3 concentrations available. Because they don't live very long and they don't eat other fish, their mercury load is negligible. You could eat sardines four or five times a week and likely be better off for it. Anchovies fall into this camp too.
Salmon is the king for a reason. Whether it's wild-caught Alaskan or high-quality farmed Atlantic salmon, the mercury levels remain consistently low. This is because of their diet and growth cycles. You can safely hit that three-times-a-week mark with salmon without breaking a sweat.
Other safe bets for frequent consumption include:
- Atlantic Mackerel (not King Mackerel, which is a mercury nightmare)
- Herring
- Trout
- Oysters and Mussels
- Shrimp and Scallops
The "Check Yourself" List: Moderate and High Mercury Fish
This is where people usually mess up. They think "fish is fish." It isn't.
💡 You might also like: Oura Ring v Ultrahuman: What Most People Get Wrong
Canned tuna is the biggest wildcard in the American diet. It’s cheap, convenient, and lean. But there is a huge difference between "Light" tuna and "Albacore." Canned light tuna is usually skipjack. It’s smaller. You can usually have two or three servings a week. Albacore, or "White" tuna, is much larger and can have three times the mercury. If you’re choosing Albacore, you should probably limit it to once a week.
Then you have the "Avoid" or "Rarely" list. These are the fish that should be treated like a birthday cake—fine once in a while, but not a staple.
- Swordfish: These are massive predators. They are mercury sponges.
- King Mackerel: Way different than the smaller Atlantic version.
- Shark: Just don't. Beyond the mercury, the ecological impact is a mess.
- Tilefish: Specifically from the Gulf of Mexico.
If you're eating these, you're looking at a "once a month" situation, or honestly, just skip them. There are better options that don't come with a side of neurotoxins.
What About the Kids and Pregnancy?
This is the one area where you can't be casual. The developing brains of fetuses and young children are incredibly sensitive to methylmercury. It can interfere with cognitive development, fine motor skills, and even peripheral vision.
For pregnant women, the goal is 8 to 12 ounces of low-mercury fish per week. Avoid the big predators entirely. Stick to the "Best Choices" list from the FDA. It’s not about fear; it’s about math. You want the brain-building DHA for the baby without the mercury interference.
The Selenium Shield: A Hidden Factor
Scientists like Dr. Nicholas Ralston have been looking at something called the Selenium-Health Benefit Value. It turns out, mercury might not be the whole story. Selenium is a mineral that actually binds to mercury and neutralizes it.
Most ocean fish have more selenium than mercury. As long as the fish has a "selenium surplus," the mercury might not be able to do much damage to your body. This is why some people can eat certain types of tuna more often than others without showing signs of mercury toxicity. However, this isn't a get-out-of-jail-free card. It’s just a piece of the puzzle that explains why some populations—like those in Japan or the Seychelles—eat tons of fish and remain incredibly healthy.
The Environmental Elephant in the Room
We can't talk about how often can you eat fish without mentioning the ocean's health. Overfishing is a crisis. If we all started eating salmon three times a week, the wild stocks would vanish.
Farmed fish used to get a bad rap—and some of it was deserved. Early fish farms were crowded, sea-lice-infested cages that polluted the surrounding water. But things are changing. Land-based recirculating aquaculture systems (RAS) and better feed management have made farmed fish a viable, even superior, option for frequent eating. Look for labels like ASC (Aquaculture Stewardship Council) or BAP (Best Aquaculture Practices).
If you’re buying wild, the Monterey Bay Aquarium Seafood Watch is the gold standard. They have an app. Use it. It tells you exactly which species are being managed well and which are being decimated.
📖 Related: Why You’re So Bloated: The Cause of Fluid Retention Explained Simply
Real World Implementation: A Weekly Seafood Strategy
Don't overthink it. If you want to maximize the health benefits while minimizing the risks, vary your intake.
Monday might be a salmon salad for lunch. Easy. Wednesday could be shrimp tacos. Friday? Maybe you split a piece of cod or haddock. That’s three servings, all low-mercury, all high-protein. You’ve hit your omega-3 goals and kept your toxic load near zero.
If you go out to a fancy dinner on Saturday and have the pan-seared Chilean Sea Bass? Fine. Just maybe stick to plant-based proteins or chicken for the next few days to let your body clear things out. Your body is actually pretty good at detoxifying small amounts of metals over time; the problem is "chronic loading"—eating high-mercury fish day after day after day.
Signs You Might Be Overdoing It
Mercury poisoning isn't like a stomach flu. It’s subtle. It creeps up.
- Numbness or tingling in the hands and feet (paresthesia).
- Generalized muscle weakness.
- A weird "metallic" taste in your mouth.
- Irritability or "brain fog" that doesn't go away with sleep.
If you’re a "tuna every day for lunch" person and you start feeling these things, it’s time to see a doctor and get a blood or hair test. It's rare, but it happens to people who get too stuck on one specific type of fish.
Summary of Actionable Steps
Stop worrying and start choosing smarter. Fish is arguably the healthiest animal protein on the planet if you play the game correctly.
- Prioritize the "Smalls": Eat more sardines, anchovies, and Atlantic mackerel. They are the cleanest fuels for your body.
- Rotate Your Proteins: Don't become the "tuna guy" or the "swordfish lady." Variety is your best defense against bioaccumulation.
- Know Your Tuna: Swap Albacore for Skipjack (Light Tuna) to cut your mercury exposure by 60-70% instantly.
- Check the Source: Use the Seafood Watch guide to ensure your frequent fish habit isn't destroying an ecosystem.
- Watch the Predators: Keep the big, long-lived fish (Shark, Swordfish, King Mackerel) to a "special occasion only" status.
- Supplement if Necessary: If you hate fish but want the brain benefits, a high-quality, molecularly distilled fish oil is a safe way to get your omega-3s without any mercury risk.
The question of how often can you eat fish doesn't have a single number for everyone, but for most of us, two to three times a week with a focus on low-mercury options is the path to peak health. Get the salmon. Just maybe skip the shark.