By Dr. Mercola
According to the latest report1 by the National Oceanic and Atmospheric Administration (NOAA), Americans increased their seafood consumption by nearly 1 pound per person in 2015, to an average of 15.5 pounds per year, or just over 4.75 ounces per week.
That’s the largest increase in seafood consumption in two decades. While this is good news, we still fall short of dietary recommendations, which call for 8 ounces of seafood per week.
Shrimp, salmon and tuna top the most-consumed list of seafood. Unfortunately, both shrimp and tuna have serious drawbacks.
On the upside, salmon, as long as it’s wild caught in Alaska is a great choice, and one-third of the increase was in fact attributed to people buying more canned Alaskan salmon. As reported by NPR:2
“That increase may stem from The Emergency Food Assistance Program at the USDA, which purchased more than $40 million in surplus canned Alaskan salmon in 2014 and 2015 and distributed it to food banks across the country.”
Eat More Seafood, but Be Mindful of Your Choices
As noted by NPR, warnings about sustainability and toxicity led many Americans to shy away from seafood over the past couple of decades. Indeed, it can be tricky to gain clarity about what’s healthy and what’s not. There are plenty of pitfalls and hazards these days.
Cold-water fatty fish is a great source of vitally important fats — both saturated and omega-3s — but the benefits of eating fish can easily be negated by selecting varieties that tend to be highly contaminated with mercury. Surprisingly, farmed fish have been shown to be even more toxic than wild fish.
There’s also the issue of food fraud. So how do you make sense of it all? I’ll do my best to break it down for you in this article.
The Case Against Shrimp
As noted in Larry Olmsted’s book, “Real Food/Fake Food,” the seafood industry struggles with quite a few problems. A majority of his book focuses on food fraud, but he also covers a number of other issues, including environmental sustainability.
Most shrimp sold in the U.S. are raised in shrimp farms in Southeast Asia. Mangroves — which are nature’s filtration system and defense against tsunamis — are cut down to house these farms. Toxic waste and chemicals from these farms also flow into waterways and destroy the ecosystem.
In addition to that, there’s well-documented use of slave labor in the shrimp farming industry. As noted by Olmsted, “It’s kind of a triple whammy. Bad for us, bad for the world, bad for the people involved — and the shrimp frankly doesn’t taste very good.”
In 2015, the U.S. Food and Drug Administration (FDA) had a record number of import refusals for shrimp. This is when shrimp is tested and found to contain unacceptable contaminants, such as banned antibiotics or elevated levels of toxins.
Some of the antibiotics used in shrimp farming are not allowed in American food production because they’re carcinogenic. Olmsted recommends avoiding shrimp in restaurants unless you’re absolutely convinced the shrimp were caught in the Gulf of Mexico.
However, there’s still the challenge of potential contamination from the oil spill and subsequent use of corexit, a chemical that is more toxic than the oil itself. It’s unclear how seafood in the Gulf of Mexico has been affected by that environmental catastrophe.
The Case Against Tuna and Sushi
Sushi is another seafood niche rife with fraud. Tuna — whether you buy it as sushi, tuna steaks or canned tuna — has the added disadvantage of being high in mercury and other contaminants.
Research3 published in 2010, which quantified the contributions to total mercury in the U.S. seafood supply by 51 different varieties of fish and shellfish, found tuna was responsible for more than one-third of Americans’ total exposure to methylmercury.4
If you eat tuna, you need to be aware of this, and take proactive measures — such as taking a handful of chlorella tablets with your meal — to counteract it.
Why Farmed Fish Are Best Avoided
At first glance, farmed fish may seem like a good idea to help protect wild seafood populations from overfishing. In reality, the industry is plagued with many of the same problems surrounding land-based concentrated animal feeding operations (CAFOs), including pollution, disease, toxicity and inferior nutritional quality.
Many farmed fish are fed genetically engineered (GE) corn and soy, which is a completely unnatural diet for marine life. Others are fed fishmeal, which is known to accumulate industrial chemicals like PCBs and dioxins.
According to toxicology researcher Jerome Ruzzin, farmed salmon is one of the most toxic foods on the market — five times more toxic than any other food product tested.
Farmed fish waste also promotes algal growth that harms the water’s oxygen content, posing risks to coral reefs and other aquatic life. Concentrated antibiotics, pesticides and other chemicals are also commonly used to fight diseases and parasites common to fish farms.
Summary of Seafood to Avoid
To summarize, seafood that is best limited or avoided altogether include:
• Shrimp, unless you can verify it was caught in the Gulf of Mexico and is clear of contamination
• Tuna (all kinds)
• Farmed fish (all kinds)
• Any fish high in mercury. Canned tuna, swordfish, grouper, marlin, orange roughy, snapper and halibut have some of the highest levels of contamination and are best avoided, especially if you’re pregnant or planning a pregnancy.
A 2015 article in Investigate West also addressed this issue, and includes a guide to how many meals per week you can safely eat based on any given seafood’s contamination level.7
Wild-Caught Alaskan Salmon — Best of the Bunch
When selecting fish, you need to weigh the health benefits against the risk of contamination. Mercury levels can vary more than 100-fold from one species to another, so by making wise choices, you can maximize benefits while minimizing risks. Here, wild-caught Alaskan and sockeye salmon stand out above the rest. They’re among the safest in terms of contamination, and among the highest in healthy omega-3 fat.
They’re also not allowed to be farmed, and are therefore always wild-caught. The risk of sockeye accumulating high amounts of mercury and other toxins is reduced because of its short life cycle, which is only about three years. Additionally, bioaccumulation of toxins is also reduced by the fact that it doesn't feed on other, already contaminated, fish. The two designations you want to look for on the label are:
- Alaskan salmon (or wild Alaskan salmon). Canned salmon labeled "Alaskan salmon" is a less expensive alternative to salmon fillets
- Sockeye salmon
As a General Rule, the Smaller the Better
As a general rule, the closer to the bottom of the food chain the fish is, the less contamination it will have accumulated, so other safer choices include sardines, anchovies, mackerel and herring. Like salmon, all of these are also high in healthy fats and omega-3s.
They’re also far less prone to fraud than other fish, in part because they’re less popular and therefore less expensive, and in part because they’re packed whole. You cannot chop up another fish to make it look like a sardine. Olmsted recommends canned seafood from Spain, which is known for the high quality of their canned seafood. Just be sure to avoid fish packed in olive oil, as the oil will undoubtedly be the cheapest possible. Opt for those packed in water instead.
Summary of Seafood to Eat More of
To recap, there are several types of fish that can provide you with valuable nutrients, including healthy fats and omega-3s, while being low in contaminants such as mercury, PCBs and other toxins. I personally have a can of sardines most days of the week and frequently include anchovies. Other top choices include:
- Wild-caught Alaskan salmon (canned or fresh) and sockeye salmon
How to Avoid Being Defrauded When Buying Seafood
To avoid being defrauded when buying seafood, your best bet is to buy your fish from a trusted local fish monger. When buying seafood from grocery stores or generic big box retailers, look for third party labels that verify quality:
- The best known one is the Marine Stewardship Council (their logo features the letters MSC and a blue check mark in the shape of a fish).
- I don’t recommend eating farmed fish, but if you choose to do so, look for the Global Aquaculture Alliance Best Practices symbol.
- Alaska does not permit aquaculture, so all Alaskan fish is wild caught. They have some of the cleanest water and some of the best maintained and most sustainable fisheries. To verify authenticity, look for the state of Alaska’s “Wild Alaska Pure” logo. This is one of the more reliable ones, and it’s a particularly good sign to look for if you’re buying canned Alaskan salmon, which is less expensive than salmon steaks.
When Buying Shrimp, Look for These Labels
While I do not recommend it, if you do decide to buy farmed shrimp, look for certifications by NaturLand, Aquaculture Stewardship Council (ASC), or Whole Foods Market’s Responsibly Farmed label. These groups certify that the shrimp has been raised according to aquaculture guidelines that protect the environment and prohibits the use of antibiotics.
If you’re buying wild-caughtshrimp, opt for shrimp that has been responsibly harvested. Look for MSC certified products.8 This certification assures that every component of the manufacturing process — from how the raw materials are harvested to how the product is manufactured — has been scrutinized by MSC and has been independently audited to ensure it meets sustainable standards.
Last but not least, opt for sustainably harvested wild-caught fish. Seafood Watch, which is part of the Monterey Bay Aquarium, offers a sustainability guide9 and Sustainable Seafood app10 for your smartphone. Labels that indicate more sustainable seafood products include:
- Whole Foods Market Responsibly Farmed 3rd Party certification.
- Fishwise: identifies how the fish was caught, where it came from and whether the fish is sustainable or environmentally threatened.
- Seafood Safe: involves independent testing of fish for contaminants, including mercury and PCBs, and recommendations for consumption based upon the findings.