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Fish and Seafood on a Paleo Diet

Most people’s mental image of “meat” is a thick, juicy T-bone steak. On Paleo, bacon might be a close second. But while there’s nothing wrong with steak and bacon, focusing too closely on just a few kinds of animals can lead to a very limited menu of poultry, beef, and pork. Even if you eat a variety of organs and different cuts of meat, restricting yourself to land animals like this can reduce the variety and micronutrient content of your diet, not to mention cutting you off from a whole world of delicious recipes! Two thirds of the Earth is covered with water; fish and other types of seafood present a wide array of Paleo meal options. While it’s important to be aware of environmental issues and potential food toxins, the benefits of eating fish are far greater than the risks, making seafood one important part of a balanced diet.

Nutritional Benefits of Fish

Fish isn’t quite as much of a micronutrient superhero as liver , but its nutritional profile is nothing to be ashamed of. In fact, the micronutrients found in fish are so important to proper brain development that some scientists speculate that we may even have evolved as coast-dwellers to take advantage of these essential nutrients.

As well as being an excellent source of protein, fish contains high levels of Omega-3 polyunsaturated fatty acids (PUFA). In particular, seafood provides significant levels of two especially beneficial Omega-3s, a pair of long-chain fatty acids called EPA and DHA. While it’s important not to eat too much PUFA, making an effort to eat some O3s can actually be healthy, because the ratio of Omega-3 to Omega-6 also matters, and the modern diet contains far too much O6 and not nearly enough O3. Eating high-quality seafood can help you improve your health by balancing this ratio: studies have shown that moderate doses of EPA and DHA protect against heart disease. On the other hand, more is not necessarily better: above a “modest consumption,” (about two servings of wild-caught salmon or mussels per week) the risk of a heart attack was not lowered any further. Like safe starches, O3s are best consumed in moderation, rather than avoided entirely or eaten to excess.

Fish and other types of seafood also contain Vitamins A, C, and E, and even some Vitamin D (although to get all your required Vitamin D from food, you’d have to eat quite a lot!). Even better, seafood contains two essential minerals that can be hard to find from other foods. Iodine is one: table salt is fortified with iodine, so most people eating the Standard American diet get plenty of iodine from the iodized salt found in processed foods. On Paleo, though, it’s fairly easy to develop an iodine deficiency, especially if you don’t eat a lot of seafood and aren’t used to adding salt to your food. This is dangerous, since iodine is extremely important for healthy thyroid function, brain function, and cell metabolism. Iodine deficiency can cause thyroid problems and mental retardation, especially in babies born to iodine-deficient women. Anything that lived in the sea at some point (fish, shellfish, seaweed, or anything that ate them) will contain significant amounts of iodine.

Mollusks, very high in nutrientsAnother essential nutrient found in seafood is selenium. This makes seafood an ideal dietary choice for people avoiding nuts, since the other major dietary source of selenium is Brazil Nuts. Like iodine, selenium supports thyroid function and helps prevent oxidative stress. Although most people get plenty of selenium in their diet, people with malabsorptive disorders (like undiagnosed food intolerances, Chron’s disease, celiac disease, or IBS ), and people with chronically inflamed guts are more susceptible. Thus, getting enough seafood is especially important if your gut is damaged, because people with gut disorders should generally be avoiding nuts, including Brazil Nuts.

Unsurprisingly, the fattier a fish is, the more nutritious it tends to be: salmon far ranks very lean fish like Swai or Tilapia. It’s also useful to look beyond eating only fish: mollusks (clams, oysters, and mussels) are extremely nutritious, with high levels of B vitamins and iron in addition to the micronutrients above. Shrimp, crab meat, squid, and lobster are also delicious options, and aquatic vegetables like seaweed can be prepared as a salad, or dried for a crispy, salty snack. Eating a many different types of seafood will provide you with a rich variety of micronutrients – and help keep your diet constantly interesting and exciting.

Heavy Metals and Toxic Pollutants

Fish is a tasty and very nutritious addition to your diet. But like land animals, fish can also contain various environmental toxins that seep into our seas and oceans from commercial farming operations, manufacturing plants, and other wastes. One of the most common of these toxins is mercury, a heavy metal used in all kinds of industrial applications. Microorganisms in marine environments convert this mercury into methylmercury, which accumulates through the food chain. This means that the higher a fish is on the food chain, the more concentrated the mercury in its body will be: small fish like sardines and anchovies have a very low concentration of mercury, while large, predatory fish like swordfish have more.

Mercury poisoning is the first risk of fish consumption that many people think of, and it’s definitely a serious problem – mercury is a very dangerous neurotoxin (a toxin that damages your brain and nervous system). Exposure to large amounts of mercury can cause loss of brain function in adults, and mental retardation in children. Pregnant women in particular are often warned to avoid mercury exposure, because of the risk to the fetus.

As serious as mercury poisoning is, all the well-intentioned warnings against eating fish may not actually be warranted. Mercury is certainly toxic, but the high levels of selenium in most fish naturally protects against mercury poisoning by binding to mercury, preventing the body from absorbing it. Thus, there’s no reason to avoid fish because you’re afraid of mercury poisoning. If you’re very concerned, make an effort to eat fish lower on the food chain, and avoid fish that are very high in mercury. The four worst offenders in this regard are Tilefish, King Mackerel, Shark, and Swordfish: Tuna gets a lot of bad press for being loaded with mercury, but this is mostly because tuna is very popular, not because it’s particularly problematic.

Another common concern with fish consumption is the presence of other toxins, like PCBs and dioxins. Like mercury, these chemicals are industrial byproducts that leak into the water supply and contaminate our food from there. Although these chemicals are definitely cause for concern, fish isn’t the major source of them in most people’s diets: in the US food supply, 90% of the contamination from PCBs and dioxins comes from other foods, with only 9% from fish. Reducing your fish consumption to lower your overall risk from dioxins and PCBs is like running outside naked in the winter, deciding you’re cold, and putting on one sock. It won’t hurt, but it won’t do much to help, either. In fact, if you replace the fish in your diet with foods higher in dioxins, you might even be making the problem worse. If you’re concerned about environmental toxins – and you should be – you’re better off focusing on the meat and vegetables in your diet.

One last toxin that might sneak its way into your dinner is BPA. BPA is an environmental estrogen (a chemical that prevents your hormonal systems from functioning normally) commonly used in the lining of aluminum cans: from there, it can leach into your food. If you buy salmon, tuna, sardines, or other canned fish, make sure to choose a brand packaged without BPA.

Thus, although it’s impossible to completely avoid consuming the toxins that modern industrial facilities spew out into the water, you can avoid BPA entirely by choosing your canned fish carefully, or simply buying fresh fish and avoiding cans altogether. As for mercury, PCBs, and dioxins, studies agree that the benefits of fish consumption are well worth the risks. Comparing the dangers of these toxins to the health benefits of a moderate fish intake, scientists found that the potential dangers were insignificant compared to the obvious and well-documented benefits.

The Ethical Carnivore: Undersea Edition

While fish farms don’t raise the same animal-rights issues as factory farms for mammals like cows and pigs, fish consumption raises an entirely different kind of ethical issue: sustainability. The oceans are vast – but they aren’t endless. Our current fishing practices are simply catching too many fish, diminishing populations faster than the fish can reproduce. This leads to long-term population decline, which has the potential to disrupt entire ocean ecosystems. Further destruction of the undersea food chain can then occur when fishermen move on down the food web, slowly eroding the base of the food chain and removing the food that other species need to survive. Many species of fish are becoming endangered due to unsustainable fishing practices, especially fish that reproduce slowly, and fish that we especially like to eat, like tuna and cod.

Unsustainable fishing practices are putting ocean resources in serious danger, and these poor fishing practices are directly driven by consumer demand: if nobody wanted to eat salmon, nobody would bother catching it. This puts the responsibility on all of us to make sure we only eat fish that can are harvested in sustainable ways. Good methods include hook-and-line fishing (the kind you’d do with a fishing rod and a worm) and specially designed traps that allow young fish to escape while doing very little damage to the seafloor. Bottom trawlers, by contrast, drag huge nets over the seafloor, destroying local ecosystems and killing everything in their path. As well as damaging the physical face of the ocean floor, these methods trap huge amounts of bycatch, fish that just happen to get caught in the net even though the fisherman wasn’t looking for them and has no use for them. Bycatch kills huge numbers of animals for no reason – they’re just thrown back into the sea, and most of them don’t survive.

Avoiding fish caught with unsustainable methods can be tricky, since fish companies love to make their harvesting practices sound better than they are. If you’re lucky enough to buy your fish from a local fisherman, you’ll be able to ask questions firsthand about how the fish was caught. If you’re stuck with the grocery store, look for the blue Marine Stewardship Council certified label to find fish that was sustainably harvested by operations that treat their workers fairly. When you’re dining out, the Monterey Bay Aquarium offers wallet-sized cards that you can print and carry with you.

Fresh fish

The Great Debate: Farmed vs. Wild-Caught

One of the biggest ethical issues concerning fish is the choice between wild-caught and farm-raised animals. At first glance, fish farms seem like the perfect solution to overfishing: if humans like to eat a particular species of fish, we can just grow more of it, saving wild populations from depletion. This is why nobody is worried about whether cow or chicken populations can keep up with demand: if we need more, we’ll just breed them. Why couldn’t we do the same with fish?

Unfortunately, it isn’t quite so simple. For one thing, the fish most people like to eat are high enough up on the food chain that they eat other fish. This means that fish farms have to catch smaller fish to feed their products – they simply shift the damage of overfishing further down the food chain, rather than eliminating it. This problem can be somewhat alleviated by raising naturally vegetarian fish, like barramundi or tilapia, which don’t require much (if any) other fish in their diet.

Farmed fish also raise the possibility of genetic modification – a company called AquaBounty, for example, has introduced a new breed of salmon called the AquAdvantage Salmon, which is genetically engineered to grow twice as fast as an unmodified fish. Such genetic modification raises the same health concerns as modification of plants like soy and corn, as well as ethical considerations (AquAdvantage salmon would be the first genetically modified animals to be distributed for human consumption). Also, even if these hybrid fish don’t pose any risk at all to humans, they could still damage local ecosystems if they escaped from fish farms (as farmed fish quite commonly do) and began breeding with wild, unmodified fish populations.

Furthermore, although most people aren’t as horrified by the crowding and unnatural conditions in a fish farm as they are by the cruelties inflicted on factory-farm animals, the fact remains that diseases and infections spread very rapidly in a fish farm environment, requiring farmed fish to be regularly dosed with massive amounts of antibiotics. These drugs can then go on to damage the health of the person eating the fish. Fish farms also have the potential to release enormous amounts of pollutants in very concentrated doses, since they involve much more concentrated populations of fish than would ever occur in the wild.

To add to these disadvantages, the fish themselves are not as nutritious: farmed fish have no Vitamin D and contain much lower levels of the Omega-3s that make seafood so beneficial. Conversely, they do contain higher levels of Omega-6s, which most of us get too many of already. This is most likely due to their diet – a steady stream of industrially manufactured pellets can’t replace the variety of fresh, wild food the salmon would otherwise be eating. The amount of waste generated by these fish farms also makes farmed fish slightly higher in toxins than their wild-caught cousins (although even farmed fish don’t contain enough toxins to outweigh the benefits of eating them).

Fish farms aren’t perfect. But they aren’t all doom and gloom either: a new type of farm, based on a model called recirculating aquaculture, shows serious potential to resolve at least some of the problems with current fish farming methods. A recirculating aquaculture operation involves both fish and fields: the fish are grown in tanks on land, and their waste provides fertilizer for the plants. This eliminates the problem of fish farms dumping waste into the oceans and the danger of farmed fish escaping into wild populations. Scientists studying sustainable aquaculture are also experimenting with different ways of feeding farmed fish to make aquaculture operations truly sustainable and farmed fish more nutritious – one USDA formula uses corn, soy, wheat, and barley proteins instead of food made from smaller fish. While this may or may not be ideal for human nutrition (meat from grain-fed fish might have some of the same nutritional deficiencies as meat from grain-fed cows), it represents an encouraging effort to preserve ocean resources and support sustainable development.

By combining recirculating aquaculture operations with naturally herbivorous fish, fish farmers have the potential to create truly sustainable operations that can help take some of the pressure off the world’s overexploited oceans. However, it’s important to note that not all fish farms are recirculating aquaculture operations. For consumers concerned about the environment, therefore, both wild-caught and farm-raised fish can be good options, depending on the specific operation in question. The most important point is not whether the fish came from an ocean or a farm, but whether it’s nutritious and non-toxic to eat, and whether it’s produced in a sustainable way. Rather than making snap judgments in favor of one or the other, look for the Marine Stewardship Council label and focus your efforts on supporting workable, real-world solutions to the problem of overfishing.

Fish Oil Supplements

Whether they’re tight on money, too busy to cook, or just plain don’t like the taste of fish, many people try to get the benefits of dietary seafood from fish oil supplements instead. Unfortunately, supplements are rarely as good as the real thing. Although they provide a more highly concentrated dose of EPA and DHA, this might be a drawback, rather than a benefit, as too much O3 contributes to inflammation. Moreover, fish oil does not contain any of the other beneficial nutrients found in fish, and isn’t absorbed as well.

If you do take fish oil, make sure to choose it carefully. Unlike whole fish, fish oil does not contain selenium to counteract the negative effects of any mercury that it might contain. Thus, it’s very important to find a brand made from fish with low levels of mercury. If you’re pregnant, nursing, or particularly worried about mercury poisoning, ask the manufacturer for a Certificate of Analysis, verifying that an independent lab has tested the product and found it safe. You could also take a selenium supplement with your fish oil, or eat another dietary source of selenium, such as Brazil nuts. As well as paying attention to the potential toxins, choose a brand of oil made from sustainably harvested fish: it should be certified by a reputable body. To get some additional vitamins with your O3s, maximizing the benefit of your supplement, you could also look into fish liver oil.

Once you’ve chosen and bought your supplement, make sure the oil is fresh by breaking open a capsule and smelling it. If it smells like rotten fish, it’s rancid – throw it out! Since fish oil goes bad very easily, make sure to keep it in a cool, dark place so that it stays fresh. Take the supplement with a fatty meal, to aid in absorption: all the DHA and EPA in the world won’t do you any good if your body can’t use it.

By paying attention to the brand you choose, treating it carefully, and taking it correctly, you can maximize the benefits of a fish oil supplement. But taking a pill for anything should always be your second choice: before you think back on your grandmother’s soggy fish sticks and despair, try some of the recipes below and see if you can’t find a way to prepare fish in a way you like.

Fish and Seafood Recipes

There are two kinds of fish recipes: recipes for people who love fish and want to revel in it, and recipes for people who can barely stand it and want to disguise the taste as much as possible. If you find yourself hovering over the fish counter in breathless anticipation each week, you’ll want a recipe that lets the fish itself shine. Baking or grilling a whole fish isn’t as difficult as it sounds, and makes an impressive centerpiece for a special-occasion dinner. Eating the whole fish also has substantial nutritional benefits: the bones, eyes, and skin are all good for you. This tuna steak recipe unapologetically showcases the tuna flavor with a fresh-tasting marinade. For a light summer dinner, try some shrimp with fruity salsa or baked salmon on a bed of greens. Canned sardines are a tasty snack on the go, and also make a delicious topping for a spinach salad – as a bonus, the fat in the sardines will help you absorb the valuable fat-soluble vitamins in the spinach.

If you’re not wild about the taste of fish but want to enjoy the health benefits anyway, try a recipe like fish tacos, which have a very mild taste if you make them with a white fish like tilapia. You can add tomatoes, herbs, and spices to disguise the flavor of the fish, or even replace half the fish with a very mild-tasting vegetable like cauliflower. In this recipe for salmon with cherry tomato salsa, the bright, refreshing taste of the tomatoes balances out the stronger flavor of the salmon. Thanks to the potatoes in these fish cakes, the taste of the fish itself is quite mild – to further disguise it, you could eat the cakes with tartar sauce or another kind of dressing.

Seafood skeptics might also want to look beyond fish: other types of seafood contain many of the same nutrients, without the strong fishy taste. Scallops are extremely nutritious and have a very mild flavor – try them baked or pan-fried, or as a salad topper in this spicy scallop salad. Mussels are among the most nutrient-dense foods available, and taste delicious covered in a variety of sauces, from this very sophisticated white wine sauce to a simple topping of butter and pepper.

No matter what kind of fish recipe you prefer, if you live anywhere near the coast, you’ll want to check out your local fish markets: everything tastes better when it’s fresh, and fish is no exception. A local fisherman can also answer all kinds of questions about how the fish was harvested, to help you make the most healthy and sustainable choices.

Fresh salmon


As a delicious source of many important vitamins and minerals, seafood is an important component of a balanced Paleo diet rich in high-quality animal products. Although many people are afraid of mercury poisoning, the high levels of selenium found in seafood provide an effective antidote to any mercury-related problems – if you take reasonable precautions to avoid the fish that are highest in mercury, you’ll be fine.

Another common objection to fish is sustainability: if the oceans are so devastated by overfishing, should we really be eating any seafood at all? If we’re lucky enough to have a choice about what we can eat, shouldn’t we avoid fish and give the planet a chance to recover? Sustainability is a serious problem, and a valid concern, but by choosing to support ethical seafood, you can actually help encourage the fish industry to develop more environmentally friendly ways of producing fish, whether through better fishing methods or through sustainable fish farms. While there’s no need to eat fish for every meal (or even every day) it’s one important part of a nourishing, balanced diet: experiment with fish recipes until you find one you like, and enjoy the chance to add a variety of nutritious recipes to your culinary routine.