A Guide to Choosing the Cleanest and Healthiest Seafood (Hint: Canned Salmon Tops the List)

Aug 11

Read time: 6 minutes

In Leviticus 11:9–12, the Bible gives clear instructions on which fish are considered clean: “Of all the creatures living in the water... you may eat any that have fins and scales.”

That’s it—two simple guidelines. But they couldn’t be more relevant today.

Why? Because today’s seafood industry is filled with confusion. Between environmental contaminants, questionable farming practices, and misleading marketing, it’s become harder than ever to know which fish are truly safe, and which are likely to do more harm than good.

While some fish are incredibly nutrient-dense, others can burden your body with heavy metals, microplastics, parasites, and hormone-disrupting toxins.

So, how do we make wise, biblically aligned, biologically sound choices? Let’s walk through it.

God's Blueprint for Seafood: What’s Clean and What’s Not?

When it comes to choosing the healthiest seafood, God didn’t leave us guessing.

Scripture offers clear guidance on which sea creatures are considered clean and beneficial, and which ones to avoid. And modern science is now revealing just how wise those distinctions, described below, truly are.

1. Avoid: Shellfish and Bottom Feeders

Shrimp, crab, lobster, clams, muscles, oysters, and scallops may be delicacies in the modern world, but they’re explicitly called out in Scripture as unclean.

Shellfish are scavengers, and their God-given role is to clean up the ocean and river bottoms, not to be eaten.

Research shows that these "bottom feeding" creatures essentially act like underwater vacuum cleaners, feeding on decaying organic matter, sewage runoff, dead fish, and other waste materials. Because of this scavenging role, they tend to accumulate a high concentration of contaminants from their environment.

Studies have shown that shellfish often contain dangerous levels of heavy metals like mercury, cadmium, arsenic, and lead, especially when harvested near industrial zones, ports, or sewage outflows. When you eat shellfish regularly, these metals can build up in your body over time. This is linked to kidney damage, nervous system dysfunction, hormonal disruption, and increased cancer risk.

Shellfish are also known to harbor pathogenic toxins (including paralytic shellfish toxins), bacteria, and viruses, such as Vibrio and norovirus.

These can cause severe foodborne illnesses even in healthy children and adults, along with other symptoms affecting the brain and muscles, in some cases. Shellfish's filter-feeding nature means they concentrate microorganisms and toxins from the water directly into their tissues, which you then consume when you eat them.

Even when shellfish are farmed, the risks remain. Many commercial shellfish farms operate in coastal areas with poor water circulation. They're often in close proximity to pollution sources, like fish farms and wastewater treatment plants. And because of their unique biology and feeding methods, there’s no effective way to fully “cleanse” shellfish of these toxins once they’ve absorbed them.

Simply put: shellfish serve a purpose in God’s ecosystem: to cleanse and recycle waste from marine environments. But they were never intended to be eaten.

Modern science continues to affirm the biblical wisdom of steering clear of:

Clams
Mussels
Oysters
Geoduck
Scallops
Lobster.

2. Choose: Fish with Fins and Scales

Fish that meet the biblical “fins and scales” rule tend to live in cleaner waters, feed higher in the food chain, and have shorter lifespans (meaning they accumulate fewer toxins). You can see why these are the type of seafood that are considered clean and suitable for eating.

This spiritual distinction aligns with biological and environmental realities that directly affect your health.

For example, fish live in flowing waters—like oceans, rivers, and lakes—where water is more oxygenated and less stagnant. Unlike bottom-dwelling species (shellfish), they typically feed higher in the food chain and do not scavenge waste. They also tend to have shorter lifespans, which means they accumulate fewer toxins like mercury and PCBs over time.

Here are some tips for choosing clean, safer, and more nutrient-dense seafood options.

✔ Stick to small, wild-caught fish like sardines, herring, kipper, and anchovies.

These fish are very low on the food chain and don't live for as long as larger fish, meaning they have minimal exposure to environmental toxins like mercury, dioxins, or microplastics.

At the same time, they’re packed with essential nutrients, including heart-healthy omega-3s (EPA and DHA), vitamin D, selenium, and iodine.

Organizations like the American Heart Association and Harvard School of Public Health suggest that everyone eat fish about twice a week to reap their benefits. For example, in an analysis of 20 studies involving hundreds of thousands of people, those who ate one to two 3-ounce servings of fatty fish a week, such as salmon, anchovies, or sardines, experienced about a 36% reduced risk of dying from heart disease and 17% reduced risk of death by any cause.

Because small fish are often eaten whole, bones and all, they’re a rich source of calcium, phosphorus, and natural collagen, which helps support your own bones, joints, skin, and connective tissue health.

Research confirms that eating small oily fish can also help to lower inflammation, support cardiovascular health, and even improve mood and cognitive function.

These fish are the types recommended for pregnant women, too (rather than bigger fish) due to their low mercury and heavy metal content.

✔ Opt for wild-caught salmon, particularly canned Alaskan salmon.

Wild salmon is one of the most nutritious fish available, considering it's rich in omega-3 fatty acids, astaxanthin (a potent antioxidant), high-quality protein, and B vitamins.

Canned salmon, especially from Alaska, is typically pressure-cooked at the source, which not only preserves these nutrients but also kills any potential parasites. Plus, canned salmon is shelf-stable, budget-friendly, and incredibly versatile for quick meals (such as making salmon patties).

The key here is to choose canned salmon that's labeled “wild-caught” or “Alaskan,” as farmed salmon often contains artificial colorants, is raised on a grain-based diet, and may have higher levels of pollutants and antibiotics.

✔ Try trout from clean rivers or lakes, but avoid farm-raised varieties.

Trout can be another healthy option if it’s wild-caught from unpolluted waters.

However, today, much of the trout sold in grocery stores is farmed in densely populated tanks or inland ponds with limited water movement and exposure to antibiotic use. These farming conditions can lead to higher concentrations of harmful bacteria, parasites, and environmental contaminants.

Wild river or lake trout, especially from spring-fed or cold, fast-moving streams, tend to be cleaner and more aligned with God's original design for nourishing fish.

When buying trout, always:

Choose wild-caught over farmed
Look for country or region of origin (avoid ambiguous or unlabeled sources)
Verify it's not raised in closed, crowded tanks

Here are some examples of what to look for:

Wild-caught rainbow trout from Idaho or Montana: These trout often come from spring-fed hatcheries or clear rivers like the Snake River or Bitterroot River. Look for products labeled wild-caught or spring-fed and avoid those marked farmed or pond-raised.

Brook trout from the Appalachian Region or Adirondacks (Northeast U.S.): Brook trout from cold, oxygen-rich mountain streams are a native species and are often caught in low-pollution areas with minimal industrial runoff.

Trout from New Zealand or Iceland (wild-caught). These regions have strict environmental regulations and often pristine freshwater sources.

Golden trout or cutthroat trout from Western U.S. Alpine Streams: These are rarer, heritage trout species that live in high-altitude, spring-fed streams.

Lake trout from the Great Lakes (such as Lake Superior)

Farm-Raised Fish: Is It Ever Okay?

Fish farming isn’t inherently bad, but the "how" matters. Fish that are raised in cramped, dirty enclosures, fed processed pellets, and treated with antibiotics are not healthy to eat.

On the other hand, if a farm mimics a natural ecosystem (for example, it has large areas with flowing water and clean surroundings), it’s possible to raise clean, farmed fish, particularly species like rainbow trout or Arctic char.

Still, if you’re unsure of the source, opt for wild-caught.

Beware: Bigger Fish Are More Toxic

The larger and longer-lived a fish is, the more toxins it accumulates. Avoid or limit these:

✘ Tuna (bluefin and albacore)

✘ Swordfish

✘ Shark

✘ King mackerel

✘ Tilefish

✘ Catfish

These are often high in mercury and environmental pollutants, and were likely not eaten by the faithful in biblical times.

What About Parasites in Wild-Caught Fish?

This is a valid concern. The good news is: freezing or canning wild fish usually kills harmful organisms.

In fact, U.S. regulations require that wild fish intended to be consumed raw (like sushi) be flash frozen to very low temperatures and kept frozen for at least 15 hours to kill parasites.

Canned fish like sardines and salmon are heat-treated during processing, making them safe and shelf-stable. The heat helps to kill dangerous germs, making them even safer than most fresh fish.

If you do eat fresh wild fish, make sure it’s been frozen first, or be sure to cook it thoroughly.

Final Thoughts: Fish As a Sacred Food

Fish were a staple in the biblical diet, and for good reason. They’re packed with:

Omega-3 fatty acids for brain and heart health
High-quality protein
Minerals like iodine, selenium, calcium, and magnesium
Fat-soluble vitamins like D and A

But not all seafood is created equal. When you follow God's blueprint—eat only fish with fins and scales, and avoid shellfish—you not only protect your body from modern pollutants, but you also reconnect with the food rhythms of ancient faith.

References:

https://www.ncbi.nlm.nih.gov/books/NBK470225/

https://pubmed.ncbi.nlm.nih.gov/38393035/

https://doh.wa.gov/community-and-environment/shellfish/recreational-shellfish/illnesses/biotoxins/paralytic-shellfish-poisoning

https://www.fisheries.noaa.gov/topic/sustainable-seafood

https://www.ncbi.nlm.nih.gov/books/NBK470225/

https://www.fda.gov/food/consumers/advice-about-eating-fish

https://www.hopkinsmedicine.org/health/wellness-and-prevention/healthy-fish

https://nutritionsource.hsph.harvard.edu/fish/

https://doh.wa.gov/community-and-environment/food/fish/healthy-fish-guide

https://health.clevelandclinic.org/3-fish-you-should-love-and-3-fish-you-should-snub

https://www.washington.edu/news/2024/04/04/canned-salmon/