If You Choose Wisely, the Benefits of a High Fish Diet Can Still Outweigh the Risks Associated with Mercury Contamination
December 23, 2012
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By Dr. Mercola
Fish has made the news a few times lately. Some say Americans aren't eating enough of it, while others warn of mercury dangers. It's certainly a complex issue, as waterways are increasingly polluted and so many people are deficient in the omega-3 fats critical for health...
So, should you or shouldn't you eat fish?
Here, I will review a few of the fundamentals that need to be factored in to help you optimize your diet while reducing your exposure to environmental toxins like methylmercury as much as possible.
Fish has always been the best source for the animal-based omega-3 fats EPA and DHA, but as levels of pollution have increased, this treasure of a food has become less and less viable as a primary source of healthful fats.
However, there are still exceptions, and the key is to understand which types of fish are the least contaminated.
Interestingly enough, and fortunately for us, the types of fish that tend to suffer the least amount of toxic contamination also happen to be some of the best sources of fat and antioxidants. So, by choosing wisely, the benefits of a diet high in fish can still outweigh the risks.
In the video above, I interview Randy Hartnell, founder-president of Vital Choice Wild Seafood and Organics. I'm a huge fan of their sockeye salmon, and beside a fish dinner at a restaurant here or there, Vital Choice salmon is about the only type of fish I eat, for the very reasons mentioned above — it's less likely to be contaminated, for reasons I'll review in a moment, and the nutritional profile is far better than most other fish, including other types of salmon.
Hartnell spent more than 20 years as a commercial fisherman before forming his company in 2001, which features sustainably harvested wild salmon that are particularly low in heavy metals.
The reason he switched from being a commercial fisherman to a supplier was because farmed salmon exploded onto world markets, and quite simply crowded out the wild-caught variety. People typically didn't understand the difference between the two, and farmed salmon was (and still is) cheaper. In a matter of a few years, grocery stores and restaurants across the US and beyond had switched to farmed salmon.
"Out of frustration, I went out with a friend, and we just started traveling around the country. We'd go to food stores like Whole Foods or Wild Oats. We'd set up our grill out in front. We'd barbecue our wild salmon. And we'd tell the story why wild is better than farmed," Hartnell says.
"People were very receptive. Often we would hear, 'Well, this is great, but they hardly ever have it here. Where can I get it?' Over and over again, I'd hear it. I'd have to tell them, 'I'm sorry. I don't know.' Then one day, a light bulb went off, and I said, 'I can send it to you. I'll send you some.'"
The rest, as they say, is history. Shipping the highest quality possible wild-caught Alaskan salmon right to your door is now his primary business. You can learn more on his website, VitalChoice.com.
Why Wild-Caught Alaskan Sockeye Salmon is a Good Option
There are three major differences between wild-caught and farmed salmon, and once you realize how different the fish are, based on how they were raised, you'll see why opting for the cheaper alternative isn't the wisest choice:
- Fish Health — Wild salmon return to their native spawning grounds each year, without you having to do anything, while farmed salmon are kept in pens. Naturally, fish swimming in the wild get more exercise, and this alone make wild fish healthier than their incarcerated counterparts. As explained by Tony Farrell1 with the University of British Columbia Zoology department, fish kept in constrained environments become the aquatic version of "couch potatoes," with similar health consequences as humans face when we don't exercise enough.
Recent research2 has shown that survival rates of fish that have received sufficient exercise is 13 percent higher than the "couch potato" controls, and the exercise-conditioned fish had better growth, and stronger immune systems, courtesy of certain gene activations.
- Nutritional content — Wild salmon swim around in the wild, eating what nature programmed them to eat. Therefore, their nutritional profile is more complete, with micronutrients, fats, minerals, vitamins, and antioxidants like astaxanthin (which gives salmon its pink, or in the case of sockeye, red-colored, flesh).
Farmed salmon, on the other hand, are fed an artificial diet consisting of grain products like corn and soy (most of which is genetically modified), along with chicken- and feather meal, artificial coloring, and synthetic astaxanthin, which is not approved for human consumption, but is permitted to be used in fish feed.
Mother Nature never intended fish to eat these things, and as a consequence of this radically unnatural diet, the nutritional content of their flesh is also altered, and not for the better. Farmed salmon tastes different than wild-caught, and much of it has to do with the altered fat ratio, which is dramatically different. Farmed salmon contains far more omega-6, courtesy of their grain-based diet.
The ratio of omega-3 to omega-6 fat of wild salmon is far superior to farmed. Wild salmon typically has 600 to 1,000 percent more omega-3s compared to omega-6s. So whereas farmed salmon has a 1 to 1 ratio of omega-3s and omega-6s — again due to its "junk food" diet — the ratio for wild sockeye salmon is between 6 and 9 to 1. This is important, because if you're trying to improve your omega-3 to omega-6 balance, you simply will not accomplish it with farmed salmon...
- Environment — Probably around 99 percent of farmed salmon are raised in net pens in the open ocean. All the excess food that is dropped in ends up going out in the environment — the genetically engineered ingredients, the pesticides, the antibiotics and chemical additives. Anything the fish do not consume, along with all their now unnatural waste products, end up contaminating the environment. According to a new report from Scotland, some salmon farms have increased their use of pesticides 110 percent over the past four years, adding to the toxic burden of both the environment and your body. To learn more about the many hazards of fish farming, check out FarmedAndDangerous.org.3
There's also the vegetarian or vegan ethical aspect. Wild sockeye salmon are the vegetarians of the salmon world. Their diet consists of krill, plankton and algae, and they are caught at the very end of their life cycle. By the time they enter the fishing grounds, they've lived 95 percent of their natural life in the wild. At the end of their life, they fight their way up-river to spawn, after which they die a natural death — unless they're caught by a fisherman or get eaten by some other predator.
Beware of Mislabeled Salmon
Unfortunately, salmon are often mislabeled. According to Hartnell, studies have discovered that as much as 70 to 80 percent of the fish marked "wild" were actually farmed. This includes restaurants, where 90-95 percent of salmon is farmed, yet may be mis-listed on the menu as "wild." The following tips that can help you determine whether the salmon is authentically harvested Alaskan fish are:
- Canned salmon labeled "Alaskan Salmon" is a good bet, as Alaskan salmon is not allowed to be farmed.
- In restaurants, mislabeled salmon will typically be described as "wild" but not "wild Alaskan." This is because authentic "wild Alaskan" is easier to trace. The term "wild" is more nebulous and therefore more often misused. In many ways it is very similar to the highly abused "natural" designation.
- Whether you're in a grocery store or a restaurant, ask the seafood clerk or waiter where the fish is from. If it's wild, they will have paid more for it, so they're likely to understand the value proposition. Since it's a selling point, they will know where it came from. If they don't have an answer for you, it's a red flag that it's farmed, or worse... The US Food and Drug Administration is moving forward with approving genetically engineered salmon to be sold, and as you know, GE foods still do not need to be labeled in the US.
- Avoid Atlantic salmon, as all salmon labeled "Atlantic Salmon" currently comes from fish farms.
- Sockeye salmon cannot be farmed, so if you find sockeye salmon, it's bound to be wild. You can tell sockeye salmon from other salmon by its color. It's bright red as opposed to pink. The reason again for this bright red color is its superior astaxanthin content. Sockeye salmon has one of the highest concentrations of astaxanthin of any food.
The Best and Worst Fish to Eat in Terms of Environmental Toxins
Most major waterways in the world are contaminated with mercury, heavy metals, and chemicals like dioxins, PCBs, and other agricultural chemicals that wind up in the environment. This is why, as a general rule, I no longer recommend getting your omega-3 requirements from fish. However, I do make two exceptions.
One is authentic, wild-caught Alaskan sockeye salmon; the nutritional benefits of which I believe still outweigh any potential contamination. 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.
Whenever I consume fish, I always seek to consume it with a handful of chlorella tablets. The chlorella is a potent mercury binder and if taken with the fish will help bind the mercury before you are able to absorb it, so it can be safely excreted in your stool.
The second exception is smaller fish with short lifecycles, which also tend to be better alternatives in terms of fat content, so it's a win-win situation — lower contamination risk and higher nutritional value. A general guideline is that the closer to the bottom of the food chain the fish is, the less contamination it will have accumulated. This includes:
If you insist on eating typical, store-bought fish and want to know more about the extent of your mercury exposure, I urge you to check out the online mercury calculator4 at GotMercury.org to get an idea of the risks. Additionally, as mentioned above, you may want to consider taking a natural mercury chelators with any fish dinner. This includes zeolite (green clay), chlorella, and fermented vegetables.
Larger fish, which tend to live longer and have the highest contamination levels and should be avoided include (please note this is not an exhaustive listing):
|Tuna (tuna steaks, sushi, and canned)
||Sea bass and largemouth bass
Do Detoxifying Nutrients in Fish Cancel Out Harm from Mercury Contamination?
While some believe that methylmercury in seafood is counteracted by other nutrients in the fish, such as selenium, which help your body eliminate the toxins, recent research has shown that this hypothesis is likely false. A French research team sought to determine whether mercury from fish is less harmful than other dietary mercury,5 and whether beneficial nutriments from fish might counterbalance the deleterious effects of fish-associated mercury. Mice were one of three diets:
- Fish-based methylmercury diet: A diet that included fishmeal produced from fish containing five micrograms of methylmercury contamination per gram
- Added methylmercury diet: A special diet higher in DHA and EPA, with added methylmercury chloride (considered more toxic than fish-associated methylmercury) also totaling five mcg/g
- Control diet without mercury
Apart from mercury and selenium content, the three diets were comparable. Interestingly, only the fish group suffered significant behavioral abnormalities at the end of 58 days! The authors concluded:
"The two mercury-containing diets are differing by the fact that mercury was brought by the addition of either pure methylmercury chloride or by mercurial species associated to fish. Therefore, any differential effects observed between MeHg-containing and fish-containing diets should be attributed to different chemical species of mercury present in one diet and absent from the other and vice-versa along with the possible intervening role of fish PUFA and selenium.
If the beneficial role of fish nutriments such as PUFA and selenium was to counteract MeHg effects, the pattern of effects displayed after exposure to the fish-containing diet should appear less severe than that observed with the MeHg-containing diet. But in the present study, the mice fed the fish-containing diet displayed worse behavioral performances than those fed the control and the MeHg-containing diets, although the brain structures of both mercury-contaminated groups of mice contained comparable levels of mercury and even less in the striatum of those fed the fish diet.
Therefore, the different chemical species of mercury within fish flesh are likely to explain the deficit in cognitive performance in the Y maze and the decreased locomotory activity in the open-field maze."