The Healthiest Fish to Eat—And the Ones to Never Touch
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Being honest, I’ve dodged writing about fish until now. I don’t eat it much due to the lack of quality and contaminants such as mercury, which many fish contain.
However, I believe we would have eaten ancestrally, so it is, in theory, part of a real food, human diet. And, with a bit of consideration, it can be included today. Plus, it’s tasty.
So, is fish still a smart thing to eat? Is wild-caught salmon worth the extra tenner? Are sardines as healthy as everyone claims, or are we just pretending because they come in cute tins?
And perhaps the bigger question—do we need to eat fish to be healthy?
This post tackles all of it. No fluff. No scaremongering. Just real info to help you figure out which fish are worth eating and which ones are better left at the fish counter looking sad.
We’ll talk mercury levels, the difference between wild and farmed, which fish offer the most nutritional benefits, and which ones are doing more harm than good.
And we’ll do it in a way that makes sense—even if you’re not a marine biologist or a registered dietitian.
Let’s get into it.
TL;DR – The Healthiest Fish to Eat (And What to Avoid)
- Wild-caught fish like sockeye salmon, rainbow trout, and sardines are rich in omega-3s and lean protein and have real health benefits.
- Avoid mercury-laden fish like king mackerel, orange roughy, and swordfish, as they contain high mercury levels and other contaminants.
- Farm-raised fish often lack the nutritional value of wild options and may contain synthetic dyes, antibiotics, and unhealthy fats.
- Fish can support heart health, brain function, and overall health, but it’s not essential, especially if you’re eating eggs, meat, and butter.
Why Fish Is an Ancestral Food—But Not a Must for Everyone
Let’s start with a bit of common sense.
Fish can be a great part of the human diet—but only if you live somewhere with access to clean, nutrient-rich waters and fish worth eating.
Our hunter-gatherer ancestors didn’t eat sea bass flown in from Chile. If they lived near rivers, lakes, or coastlines, they fished. If they didn’t, they didn’t. Simple as that.
That means fish is ancestral, but conditional. It’s not like red meat or animal fat, which were central staples for human survival across climates and continents.
Fish was a bonus food. A nutritious one, sure—but not a requirement for health. In fact, it’s entirely possible to thrive without seafood at all, especially if your diet includes other animal-based sources of healthy fats, lean protein, and essential nutrients.
That said, if you do want to include seafood in your diet (and you live in a place where good options are available), certain fish come with real health benefits, and some come with hidden risks. You’ve just got to know what to look for.
Next up: how to tell if a fish is actually healthy… or just swimming in hype.
What Makes a Fish ‘Healthy’ Anyway?
Here’s the first thing to understand: not all fish are created equal. Just because something swims and has gills doesn’t automatically make it a healthy choice.
A truly healthy fish should tick a few boxes:
✅ Rich in omega-3 fatty acids – These anti-inflammatory fats support heart health, brain function, and even joint mobility. Wild-caught salmon, sardines, and mackerel are some of the best sources.
✅ Low in mercury and other contaminants – The bigger and older the fish, the more time it’s had to absorb heavy metals and toxins. That’s why some popular fish (like king mackerel or orange roughy) come with health warnings.
✅ Wild caught over farm raised – Wild caught fish tend to have a better nutrient profile and fewer contaminants. Farm-raised fish are often fattier, but not in a good way—they’re higher in omega-6s, saturated fat, and may be treated with antibiotics. Some are even dyed to look like their wild cousins. Yes, really.
✅ Good source of lean protein and essential nutrients – We’re talking vitamin D, amino acids, and healthy fats that support overall health, not just the illusion of it.
And let’s not forget: the nutritional value of fish also depends on how it’s cooked. Deep frying it in seed oils and breadcrumbing it to death isn’t going to win you any dietary points.
A quick pan sear in butter? Much better.
Let’s dive into the healthiest fish to eat… and the sneaky ones to avoid.
Wild Caught vs Farm Raised: The Difference Is Huge
If you take nothing else from this post, take this: wild-caught and farm-raised are worlds apart.
Yes, they’re both technically “fish,” but the nutritional value, environment, and overall impact on your health couldn’t be more different.
Farmed Fish: Fed Like Junk, Grown in Crowds
Most farm-raised fish are bred in cramped pens, fed a grain-based diet (which fish were never meant to eat), and often treated with antibiotics to stop disease from spreading in tight quarters.
That pink farmed salmon fillet you see at the fish counter? It didn’t get that colour naturally. It was dyed. Wild salmon gets its vibrant orange-red hue from eating krill and shrimp. Farmed salmon? They’re given synthetic astaxanthin to mimic that natural look.
Now let’s talk nutrition. Farmed salmon has more fat, but not the kind you want. It’s often higher in saturated fat and omega-6s due to the unnatural feed. That skews the omega-3 to 6 ratio, which can tip you towards inflammation, not health.
Other contaminants, like polychlorinated biphenyls (PCBs), which build up in farm-raised fish, are also a concern. These toxins are linked to cancer, hormone disruption, and immune issues—not exactly part of a “heart-healthy” meal plan.
But Why Are Farmed Fish Even a Thing?
Fair question—and the answer isn’t all bad.
✅ They’re cheaper and more widely available, making fish more accessible to people on a budget.
✅ They reduce pressure on wild fish stocks, helping prevent overfishing.
✅ Some species, like farmed trout or tilapia, tend to have lower mercury levels because they grow fast and eat low on the food chain.
✅ And in fairness, some farms are improving, focusing on cleaner water, better feed, and more ethical setups.
But even with those upsides, farmed fish are not the best fish to eat if your goal is optimal nutrition.
So, if you’ve got the option, go wild. Literally.
Mercury, PCBs, and Other Contaminants in Modern Fish
Now let’s talk about the elephant in the ocean: mercury.
This heavy metal builds up in water, then in plankton, then in small fish, then in bigger fish… and by the time it reaches something like king mackerel, orange roughy, or albacore tuna, you’ve got yourself a mercury fish cocktail.
Why Mercury Matters
Mercury isn’t something your body needs. In fact, it actively disrupts brain function, damages nerves, and can mess with heart health, fertility, and mood.
In high amounts, it’s especially dangerous for pregnant women and kids, but that doesn’t mean men are off the hook.
And it’s not just mercury. Due to pollution, plastic runoff, and industrial waste, fish can also carry polychlorinated biphenyls (PCBs) and other contaminants. These nasties can disrupt hormones, contribute to inflammation, and build up over time in your tissues.
That’s why eating fish should be done with a bit of strategy, not just grabbing any fillet that looks Instagram-worthy.
Mercury Levels: The Usual Suspects
Some fish high in mercury are well known:
🚫 King mackerel
🚫 Orange roughy
🚫 Tilefish
🚫 Shark and swordfish
🚫 Bigeye and albacore tuna (especially when eaten too often)
The problem isn’t a single meal. It’s eating too many fish from this list over time. Your body can’t always keep up with clearing out the buildup.
Safer Fish to Eat
Stick to options like:
🐟 Wild-caught salmon
🐟 Sardines
🐟 Herring
🐟 Rainbow trout
🐟 Atlantic mackerel
🐟 Canned light tuna (not albacore)
These are typically lower in mercury, rich in omega-3s, and offer strong nutritional benefits, without trashing your detox systems.
Can You Detox Mercury?
To an extent, yes. But it’s not a free pass to load up on tuna sashimi five nights a week.
Biohacker and Bulletproof founder Dave Asprey has a few smart tips on how to support your body’s natural detox process. Think of them as tools in your kit—not a license to eat toxic fish.
Here’s what he recommends:
✅ Use a sauna – Infrared or traditional. Sweating it out helps release stored mercury, cadmium, and other metals. Bonus points if you combine it with good hydration and electrolyte support.
✅ Take activated charcoal – It binds toxins in your gut so they can exit your body without doing damage. Especially useful after questionable meals or if you’ve had high-mercury fish.
✅ Boost glutathione – This is your body’s master detox molecule. You can supplement it directly or eat sulfur-rich foods like garlic, eggs, and onions.
✅ Try chlorella tablets – Dave suggests these if you’re eating sushi or canned fish like albacore tuna. Chlorella binds metals and helps them exit the system.
✅ Train hard (but smart) – Exercise mobilizes stored toxins. But if you feel wiped out or foggy after, pair it with charcoal or take it down a notch.
✅ Support your liver and gut – Toxins can recirculate if your digestion’s sluggish or your liver’s overworked. That’s not what you want. Prioritise sleep, hydration, and real food to keep these systems running clean.
Lastly, don’t forget selenium, which is found in seafood like sardines, eggs, and Brazil nuts. It can help block mercury absorption and reduce its harmful effects.
Bottom Line?
You don’t need to panic if you’ve eaten a dodgy piece of tuna. But if you’re regularly eating fish high in mercury, it’s smart to rotate in low-mercury options, focus on wild-caught, and use tools like the ones above to help your body stay on top of it.
The Healthiest Fish to Eat (Backed by Nutritional Benefits)
Not all fish deserve a place on your plate—but the right ones? They’re packed with omega-3s, lean protein, and nutrients that actually move the needle when it comes to health.
Let’s break down the best fish to eat, starting with one that has the looks, stats, and nutrient profile to back it up.
🐟 Wild Caught Salmon (Especially Sockeye)
This one’s the gold standard—and for good reason.
Wild-caught salmon, especially sockeye, is rich in omega-3 fatty acids, vitamin D, and high-quality protein. It’s also one of the few fish that delivers all that without the mercury baggage.
Sockeye get their deep orange flesh from eating krill and shrimp. No dyes. No tricks. Just nature doing its thing. Compare that to farmed salmon, which are usually lighter, fattier (in the wrong way), and dyed to look “healthy.”
✅ High in healthy fats
✅ Excellent source of vitamin D and essential nutrients
✅ Supports heart health, brain function, and overall health
Best served: Pan-seared in butter, topped with sea salt, and paired with roasted vegetables. Or eaten cold the next day straight from the fridge with your fingers. We’re not judging.
🐟 Rainbow Trout
This one’s criminally underrated.
Rainbow trout is often raised in cleaner, controlled environments in the U.S., meaning it’s low in mercury but still a good source of omega-3s, vitamin B12, and lean protein.
It has a mild flavour, cooks fast, and is perfect for people who “don’t really like fish.” Plus, it’s usually cheaper than salmon.
✅ Low in mercury
✅ High in omega 3s and high protein
✅ One of the healthiest fish to eat for beginners
Cook it simple: A quick pan sear, skin side down, splash of lemon, done.
🐟 Atlantic and King Mackerel (Choose Wisely)
Here’s where things get nuanced.
Atlantic mackerel is an oily fish packed with omega-3s, vitamin B12, and other nutritional benefits. It’s small, fast-growing, and doesn’t live long, so it stays low in mercury.
King mackerel, on the other hand? Avoid it. It’s near the top of the mercury fish list and is best left in the ocean.
✅ Atlantic mackerel = heart-healthy, low-mercury choice
❌ King mackerel = high mercury, poor public health choice
Know your mackerels, folks.
🐟 Sardines
Sardines are a nutritional powerhouse if you can get past the smell and the fact that they still have eyeballs.
They’re small, low on the food chain, and packed with omega-3s, vitamin D, calcium, selenium, and amino acids. Because they’re eaten whole, you get more essential nutrients in one go, including ones that support bone health and hormone function.
✅ Very low in mercury
✅ High in omega 3s and lean protein
✅ Shelf-stable, affordable, and portable
Tip: Buy them in brine, water, or olive oil, not sunflower or soybean oil. Avoid flavoured versions loaded with rubbish.
🐟 Herring
Another oily fish, like sardines, herring is popular in Northern Europe and deserves more attention.
It’s loaded with omega-3 fatty acids, vitamin D, and protein, and is typically wild-caught. If you’re into traditional or fermented foods, pickled herring is a solid option (as long as it’s not swimming in sugar).
✅ Great for brain function and inflammation
✅ A traditional food that fits well in an ancestral diet
🐟 Canned Light Tuna & Albacore Tuna
Let’s break it down.
Canned light tuna (usually skipjack) has lower mercury levels and is fine in moderation. It’s a good source of protein, easy to store, and cheap.
Albacore tuna? More refined taste, whiter flesh, but also higher in mercury. If you’re eating tuna weekly, canned light is the safer pick.
✅ Light tuna = safe-ish, high protein, budget-friendly
❌ Albacore = limit intake, especially if you eat other mercury fish
🐟 Halibut
This large flatfish has a mild, meaty texture and is great for people who want something satisfying but not too “fishy.”
It’s a lean protein, low in fat, and contains a range of vitamins and minerals like selenium, niacin, and B6.
The catch? Larger halibut can carry higher levels of mercury, so go easy on it if you’re eating it often.
✅ Good balance of fewer calories, lean protein, and micronutrients
⚠️ Eat occasionally, not every day
Not All Fish Are Equal: Ones to Limit or Avoid
Just because something is labeled “seafood” doesn’t mean it’s good for you. Some fish species come with more baggage than benefit. High in mercury, low in nutritional value, raised in toxic environments, or just flat-out not worth eating—these are the fish you’ll want to keep off your fork.
🐟 King Mackerel (Again: No Thanks)
We’ve said it already, but it’s worth repeating.
King mackerel tops the mercury fish charts. It’s the kind of fish the dietary guidelines advise against—especially for children, pregnant women, and honestly, anyone who values their nervous system.
It’s a shame because it’s tasty and rich in omega-3s. But the mercury levels? Too high to justify.
Verdict: Tastes good. Does bad things. Skip it.
🐟 Orange Roughy
This one looks posh, has a nice flaky texture, and is often marketed as a premium fish. But beneath the surface, orange roughy is a toxic time bomb.
It’s high in mercury, low in useful fats, and lives so long (up to 150 years) that it bioaccumulates contaminants the way your old sock drawer accumulates mystery items.
Verdict: A hard no. Looks nice on a plate. Doesn’t belong in your body.
🐟 Swordfish, Tilefish, Shark
Grouped together because they share the same problem: big fish = big mercury.
These predators are at the top of the food chain, which means they absorb mercury from everything below them. Unlike humans, they don’t detox.
Verdict: Strong flavour, heavy metal content. Not worth the risk.
🐟 Tilapia
Here’s where it gets a bit controversial.
Tilapia is low in mercury and high in protein, but it’s often farm raised in questionable conditions—especially when imported from overseas.
It has a poor omega-3 to omega-6 ratio, meaning it can actually promote inflammation if eaten regularly. Plus, it’s about as nutrient-dense as wet cardboard unless you’re really stretching.
Verdict: Technically not harmful in small doses, but you can do way better. Think of it as the iceberg lettuce of the sea.
🐟 Too Many Fish, Too Often
Even with good options, eating fish every day (especially the wrong types) can backfire. Rotate your choices. Focus on wild-caught, low-mercury, and nutrient-dense options.
Leave space for red meat, organ meats, eggs, and other ancestral foods that have sustained humans for millennia.
Because not all fish are worth eating—and even the good ones aren’t magic.
Best Ways to Cook and Eat Fish (Without Wrecking It)
You’ve picked a healthy fish. Now don’t ruin it with breadcrumbs, dodgy oils, or marinades full of syrup and seed oils.
Let’s keep things in line with our ancestral roots and what our body wants and craves.
🧈 Cook in Butter, Not Bottled Hype
While most advice suggests olive oil, I’ll be straight with you—I cook mine in real butter, grass-fed (bonus points for raw butter).
It’s stable under heat, tastes incredible, and it’s what our ancestors would’ve used (if they weren’t eating it raw straight from the riverbank).
Forget ultra-processed oils—butter supports brain function, satiety, and hormone health when used properly.
🍳 Add Eggs (Trust Me)
You might not find this on most seafood menus, but my go-to pairing with fish (and most things, really) is a few eggs on the side. Poached, fried, or boiled—doesn’t matter.
They’re the perfect complement: loaded with amino acids, healthy fats, and extra protein to round out the meal. Plus, eggs are about as ancestral as it gets.
🥦 Ditch the Breadcrumbs and Pasta
You won’t catch me serving fish with pasta, or any so-called whole grains. That’s modern filler food with a health halo.
Instead, try pairing fish with:
✅ Roasted vegetables
✅ A fresh salad
✅ A side of eggs
✅ A handful of seasonal berries or avocado
✅ Or just enjoy it straight, nose-to-tail style
Eat real food. Skip the fluff.
Final Thoughts: Fish That Support Real Human Health
So there you go; I did it. I finally wrote about fish; honestly, I’ve convinced myself to include more fish in my diet.
Fish can be a smart addition to your diet—if you choose the right ones.
Focus on wild-caught, low-mercury options like sockeye salmon, sardines, rainbow trout, and Atlantic mackerel. Avoid fish that sound good on paper but are swimming in mercury, pollutants, or modern farming practices that do more harm than good.
Remember: not all fish are healthy, and not all fish are necessary. If you’ve got access to clean, well-sourced options, they can add variety, nutritional value, and serious health benefits.
But if you’re sticking to red meat, eggs, and animal fats? You’re not missing out on anything essential. It’s more about what you should eliminate – ultra-processed, human-made, junk food.
Eat what your body was built to eat—real food similar to the ancestral, animal-based, carnivore, or Ultimate Human diets.
Now go enjoy a plate of wild salmon and eggs cooked in butter—you’ll have yourself a properly nourishing meal.
And that’s it… have a nutritious day!
FAQs
Which is the healthiest fish to eat?
Wild-caught salmon, especially sockeye, is widely considered the healthiest fish to eat. It’s high in omega-3s, vitamin D, and lean protein, and supports heart health and brain function.
Which fish has the highest health benefits?
Sardines pack serious health benefits—they’re low in mercury, high in omega-3 fatty acids, and offer excellent nutritional value, including vitamin D, calcium, and key amino acids.
What is the highest quality fish?
Wild-caught sockeye salmon is one of the highest-quality fish. It’s rich in healthy fats, free from artificial dyes, and far superior to farmed salmon in both taste and nutrients.
Which fish is healthy to eat daily?
Rainbow trout is a safe, nutritious option to eat daily. It’s low in mercury, often farm-raised in clean environments, and delivers consistent omega-3s, high protein, and health benefits.
