Dear Mark: Is Fish Enough, Do Carnivores Really Need It, and More

For today’s edition of Dear Mark, I’m answering several questions you guys asked in response to the fish post from last week. First, is being a pescatarian enough? Can you get what you need from seafood without eating meat, dairy, or eggs? Next, how important is fish for a carnivore? Third, how’s that Whole Foods farmed salmon? Healthy or not? Then I write a bit about canned cod liver, the underrated seafood, followed by a short blurb about whether we should worry about wild salmon sustainability as well as a question about taking chlorella to reduce heavy metal absorption from fish.

Let’s go:

Adore this Mark! Thank you!

As a basically pescatarian this has been a wonderful insight. I find it too difficult or just a bit heavy digesting meat often, but I live for seafood!

Quick follow up question- anything I could be missing not eating meat, dairy or eggs and just seafood? If so how best can I combat those issues?

I’m struggling to come up with any major deficiencies you’ll incur eating only seafood for your animal products.

However, simply eating fish probably isn’t good enough. You need to also eat shellfish, particularly the bivalves oysters and mussels.

Most people get their zinc—important for hormone optimization and thus everything—from red meat, but the best source in the entire world is the humble oyster. Just one oyster gives you nearly 100% of your daily zinc, selenium, and copper. But don’t just eat one. Eat multiple oysters often.

An affordable way to obtain oysters is to buy canned or buy the pre-shucked ones. If you get the shucked oysters, make sure they’re fresh as can be. Pick jars with “use by” dates as far off in the future as you can. Sauté these in butter or avocado oil until a crust develops on both sides, or just simmer them in some hot bone broth.

I’d also recommend getting some salmon roe, aka ikura. They usually come salt cured, little globules of DHA, vitamin D, and astaxanthin-rich phospholipids that pop in your mouth. They are far more potent a source of nutrients than salmon flesh (which is already one of the best). You can get them at Japanese markets and sushi restaurants, or order them online in bulk.

I’d eat a variety of fish. If you had to just pick one, wild salmon would be great, but you’ll be better served eating many kinds. Halibut gives great magnesium. Salmon gives great selenium, vitamin D, and omega-3s. Cod is a nice way to pack in the protein. Smaller fish provide calcium, omega-3s, and iron.

Oh, and throw in some shrimp or crabs if only for the cholesterol. I’m of the opinion that dietary cholesterol can be very helpful.

Is it okay for carnivores to skip fish?

No, it’s not. I’ll get flack for this, which I actually welcome, because the truth simply is that carnivores should be eating seafood.

For one, fish is meat. Fish are animals. Carnivores eat animals. Carnivores should eat fish.

For two, every human group who’s ever lived on the coast or within sniffing distance of it has eaten fish, shellfish, and other seafood. Hell, one of the traditional peoples that carnivores like to cite as justification for their diet are the Inuit, who ate an enormous amount of seafood—at least the coastal-living ones.

Three—and this is the most important—fish and other seafood offer nutrients that are often missing from land-based animals. Traditional soil-based foods are less nutrient dense than ever before. Feed for most livestock is more subpar than ever.

Seawater also has a different nutrient profile than soil. Sea animals are rich in iodine, copper, selenium, and manganese. I’m not saying you can’t get selenium, iodine, copper, and manganese from land foods, but it’s much harder and less reliable than eating seafood. And manganese in particular is very hard to get from land-based animals. If you’re not eating sweet potatoes or wheat germ or brown rice, you should eat some mussels—the richest source of manganese on the planet.

Also, opinion on Whole Foods farmed salmon? They convinced me it’s good, and it sure is delicious, but I’m still skeptical.

Whole Foods farmed Atlantic salmon is better than most farmed salmons.

They teamed up with a company that makes a specialized salmon feed containing fish trimmings and microalgae, which increases the omega-3 content of the salmon who eat it. They monitor and remove the PCBs (a common sea-borne toxin) from the feed before the salmon get it.

They use no antibiotics, hormones, or artificial colorants. So, while the farmed salmon at Whole Foods isn’t as brilliantly red as wild salmon, the light pink color it has comes from actual feed, not artificial dyes.

Often overlooked is canned cod liver in its own juices. It delicious and nutritious by itself. And you eat eggs, you can mash it with a few boiled eggs. Also, stay clear of seafoods that comes from the Far East.

Yes, canned cod livers are quite mild and tasty. They’re canned in their own cod liver oil and make a great source of vitamin D, vitamin A, and long chain omega-3s.

Find them in European markets or online.

If you’re not getting enough vitamin D or retinol (animal form of vitamin A, far more bioavailable) from your diet and lifestyle, cod liver oil can help. A big spoonful of cod liver oil used to be standard protocol for kids growing up for good reason—it’s great for immune function.

I believe we can leave the salmon a bit out (besides worries about contamination) – what about the other animals in the planet besides the humans that also deserve to consume these species?

Salmon is the oldest word in the Indo-European family of languages. Humans have been eating them for tens of thousands of years. They’re that important to us.

The more well-caught wild salmon we all fork out our money to buy, the more sustainable the salmon industry gets. Money talks. You won’t save the salmon by not eating them. That’s not how this works. Even the Monterey Bay Seafood Watch, the global leader in analysis of sustainable seafood, calls wild-caught salmon a “best” choice.

Great article. I usually take some chlorella when I eat high mercury fish. Will that provide adequate protection fro the heavy metals?

Chlorella can definitely remove heavy metals from humans. In one study, 90 days of chlorella supplementation lowered mercury levels in people with dental implants. In rats given cadmium, taking chlorella increases urinary excretion of cadmium and decreases its absorption.

That’s promising. However, I’m not sure if taking a single dose of chlorella as needed will inhibit acute absorption of mercury. It might need to be an ongoing process.

Thanks for stopping in today, everybody. Have a question for me on these or other Primal related topics? Let me know down below.

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

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12 thoughts on “Dear Mark: Is Fish Enough, Do Carnivores Really Need It, and More”

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  1. Great follow up with the seafood. What are your thoughts about freshwater fish, trout, walleye, bass, crawfish, etc? Thanks.

  2. What about smoked salmon? I buy Nova smoked salmon at Trader Joe’s regularly.

  3. Love almost all seafood, and found this very helpful thanks Mark. Can you follow up as to weather there is a lot of damaged protein and omega 3 in canned products- particularly wondering how cod liver stacks up after canning?

    Also if you don’t like salmon (gasp) what are the next best white fish for omega 3? How much less do they actually have…

    1. While looking for more detailed nutritional info on cod liver (as difficult to find as the product itself outside of Russian shops or the internet), I found the abstract of a study on canned cod liver lipid oxidation recently which you may find useful. They concluded that the liver itself was less likely to oxidise than the oil but that oxidation overall was not high and omega-3 content excellent. Would definitely still be interested in seeing someone smarter than myself analyze the study findings rather than just the abstract but it’s a start!

  4. I eat oysters all the time, but sadly I’ve had food poisoning on a few occasions lately. I’d love to Ben more fearless with seafood but I have noticed with climate change it’s a lot less easy to risk… would love to hear your tips about going forward as the waters warm, and what we will be likely and able to eat. Poor bivalves and crustaceans aren’t forming proper shells in some places already 🙁

    Also, a side- an updated post on food poisoning or having an upset stomach and the best food + way to recover quickly would be a lifesaver! If you have time?

  5. I get my seafood directly from Sitka AK.

    I get the 9 month share. Yes, it’s expensive, but I feel it’s an investment in my health. They have independent small fishermen.

    I agree with Mark – the more we buy, the more the supply will grow, eventually bringing down costs.

  6. Ok, but you didn’t mention whether we should be worried about the contaminated sea. How often should we have shellfish, sardines, or wild salmon? I don’t want the toxins building up in my body.

  7. Thanks for a really great post. As you come across more info on fish/seafood nutrition and our health from eating this meat, please do not hesitate to post.

  8. Mark in my mind you are becoming one of the few that seem to be a trusted voice. I follow you because I fight high blood sugar and the higher fat low carb diet is the only solution, but enough about me. My question is in regards to IBS. My husband has been struggling with a IBS for over a year and a half after having a multi day rough case of vomiting and diarrhea. Over the first few months he lost over 25 # and has only been able to gain back 8 #. Everything I read and the doctor advice suggests a very low fat diet (20%), no red meat and loads of solvable fiber in the form of high carb breads, potatoes, rice and the like. This sounds so much like the old food pyramid, I wonder if it’s medical people with little or no nutritional training suggesting what they think is a healthy diet or if this advice could be science based and true? Can you delve into this and find the truth about the best diet for people with IBS? Thank you so much for wisdom and truth about health and diet!

    1. Hey Diann,

      I would LOVE more info on this too! I’m so sorry your husband is struggling. My stomach has taken a turn for the worst after some bad gastro months ago. I’m thin as a rake and finding food so unappealing.

      I have heard Carnivore can be helpful for bad gut issues, and honestly when I think of what to eat meat fish and eggs are what I’m most drawn too. A high fibre low fat diet seems like it would be agony on the other hand. Some carnivores seem to include kelp and mushroom these days too.

      More info would be awesome and I’m very interested in all the adaptations of the carnivore diet and if it truly could be sustainable even semi long term?


  9. Fact is you need to look for fish with the less toxins and big fish and seabed fish like oysters and mussels are the worst you can eat if not made in clean water.