Should We Avoid Fish Because of Mercury?

Guest Author Raine Saunders

Did you know there is an important trace mineral in fish that helps offset the mercury content you absorb when you eat it?

For the last several decades, many health and medical sources have recommended limiting consumption of fish due to mercury content. Mercury is a heavy metal, and when it accumulates in the body can cause health problems such as damage to the nervous system, brain, and digestive tract. Based on what we know about heavy metals in our bodies, it’s certainly wise to avoid them.

Exposure to mercury from fish has been greatly feared, but widely misunderstood. Fish are a traditional food with critical nutrients for human development and support. For thousands of years, humanity has consumed fish from freshwater sources as well as the seas and oceans as an important source of these essential nutrients for good health.

Mercury occurs naturally at low levels in nature: in rock, soil, and water all across the planet. It becomes liquefied with rain and binds with organic and inorganic molecules in the environment such as from industrial sources such as the burning of fossil fuels like natural gas, coal, and oil. Some also comes from mining, waste incineration, and other commercial and industrial industries.

Mercury then flows into waterways, oceans, rivers, and lakes. Methylmercury pollution is taken in by both aquatic life and life on land. These molecules are absorbed by living organisms and into the tissues, and this is where the problem comes in. Mercury becomes part of the fat tissue of some animals and fish. When we eat these organisms we absorb it. Although there is no safe level of mercury that should be ingested, our bodies can handle lower levels of this toxin before we start to become aware of noticeable symptoms.

Vital nutrients for health found in fish

Fish are an excellent source of many vitamins and minerals: A, B6, B12, D, cholesterol, iodine, and minerals such as calcium, zinc, copper, iron, magnesium, and Omega 3 essential fatty acids DHA and EPA. DHA and EPA are important during pregnancy and lactation, as well as brain and nervous system [19-22], respiratory [1-7], and heart health. [8-11] Growing research also shows that Omega 3 essential fatty acids greatly reduce the development of degenerative disease such as atherosclerosis, depression, and cancer [8-11]. Children who eat fish receive nutritional support for brain and nervous system, and are less likely to develop issues such as hyperactivity [12-18].

Fish are also an excellent source for an important mineral many people are lacking which greatly affects the way our bodies store mercury: selenium. Not only is selenium a powerful brain nutrient, but what is now known is that selenium holds the key to avoiding mercury build-up in the body to toxic levels. So in addition to being a source for many other important nutrients, fish are one of the most bio-available sources of this key mineral.

What do the experts say?

Recent peer-reviewed data shows that trace mercury amounts in fish simply aren’t significant enough to warrant avoiding their consumption. What’s more, focusing

solely on mercury content blows the issue out of proportion, and fails to acknowledge the impact of adequate selenium intake on human health.

According to various health experts such as Dr. Dariush Mozaffarian, M.D. (cardiologist, Harvard School of Public Health), and Phillipe Grandjean of the Environmental Medicine Department of the University of Southern Denmark, fish should be a part of a varied diet because of the important nutrients found in them. Dr. Weston A. Price who traveled the world in the 1930s to learn about the profound effect of traditional diets on human health found that populations who had access to fish and shellfish from the sea had excellent bone structure and integrity.

Scientists at the University of North Dakota found evidence that mercury levels in fish are much less of an issue than what health authorities have thought in the past. Researchers at the Energy & Environmental Research Center in Grand Forks discovered that selenium present in fish is just as present as mercury, and that fish containing more selenium than the heavy metal are perfectly safe to eat. This is because mercury is attracted to selenium and will bind to it. This attraction results in mercury being excreted from the body.

Dr. Nicholas Ralston

According to Dr. Nicholas Ralston, an EERC Research Scientist: “Selenium is an essential nutrient in healthy brain development and protects the brain from oxidative damage. More importantly, selenium protects the body from mercury’s negative effects. The more selenium in the tissue, the less mercury toxicity occurs. Since fish in some areas have much higher levels of selenium than mercury, the consumer receives the healthy benefits of selenium and a natural defense against mercury.”

Dr. Ralston also works with The National Oceanic and Atmospheric Administration, and has observed that (southern) Flounder and (wild Pacific) Salmon (including Sockeye, Coho, and Chinook) have much higher selenium content than mercury. The study also revealed that that most types of shark, Pilot Whale, and Tarpon should be avoided, with Grouper being about even in selenium/mercury content.

He wants to see new standards in place for fish consumption advisories. According to a recent study conducted by the Western Pacific Regional Fishery Management Council, a new standard is being proposed by researchers called the Selenium-Health Benefit Value or Se-HBV, as a method of determining the safety of seafood.

The following types of fish have very high Se-HBV, and have been found to contain 10 to 25 times more selenium than mercury:

Albacore Tuna
Mahi Mahi
Yellowfin Tuna
Skipjack Tuna
Wahoo
Yellowfin Tuna

High quality servings of these fish will show a net decrease of mercury levels in the blood when accompanied by a healthy amount of selenium. In the Western Pacific study, only the Mako shark showed increased levels of Mercury over Selenium, while the Swordfish showed an even, 50/50 ratio of selenium to mercury.

Dr. Natasha Campbell McBride

From her research and clinical observations, Dr. McBride, author of Gut and Psychology Syndrome, has learned through her research that if gut flora in the digestive tract is healthy, it will remove or chelate mercury out of the body. If gut flora is compromised, the body tries to compensate and this results in allergies, asthma, and inappropriate reaction to environmental toxins – including retention of toxins in the body such as heavy metals.

When we eat a diet of processed food, use toxic chemicals in our daily lives, and compromise our lifestyles in a manner which doesn’t support health, we put our bodies into a condition of compromise. Our gut flora is then also compromised. This situation sets the stage for a lifetime of chronic health issues.

Sources of chemicals come from everything in our environment: paints, carpets, clothing, furniture, personal care products such as cosmetics, perfumes, toiletries, soaps, toothpaste, pharmaceutical and over-the-counter drugs, dish and clothing detergents, household cleaners, commercial cleaners and other products, swimming pools (chlorine and bromine), and processed foods. The more you eliminate from your environment and replace with truly natural substances and real food, the better your body is able to deal with detoxification and keeping healthy.

Robert Disney, Environmental Scientist

Robert Disney works for a state regulatory agency and deals specifically with waste issues. How to dispose of toxic material is usually a challenge, and detonation is his favorite method. He has spoken at conferences such as The Weston A. Price Wise Traditions Conference about how important it is to consider the prevalence of methylmercury in the environment, including seafood, and the reasons why it does not pose a health risk when we consume seafood.

In his presentations, he has explained how methylmercury is a compound that results from the combination of mercury in its elemental form with various organic and inorganic molecules from the environment. It is the most toxic form of mercury in the environment. It is created by sulfate-reducing bacteria found in low-oxygen environments in estuarine (partially enclosed coastal water bodies with one or more streams or rivers flowing into it, and free connection to the open sea) sediments of lakes or water.

Scientists recognize that selenium is critical for all normal selenoenzyme functions in the body. These enzymes are produced in the cells of all animals. The creation of selenide is necessary for selenocysteine synthesis. Brain selenoenzyme activities normally occur uninterrupted, but the presence of mercury will actually stop selenoenzyme activity.

Methylmercury has negative effects on selenoenzyme activity and is especially detrimental to the developing fetus. Mercury binds to selenium better than any other element. Methylmercury toxicity impairs selenoenzyme activities in the brain. It is quite common for a person with mercury poisoning to show silent latency, which is a delay in the appearance of signs and symptoms.

Studies showing the positive effect of selenium on methylmercury in the body

The toxic side effects of exposure to mercury are well-documented and observed in scientific studies. The protective effect of selenium against mercury in the body has also been well-noted in all species studied, such as in rats. Metabolic systems of rats are similar to humans, which is why they are used in laboratory studies.

Selenium treatments in groups of rats were nearly identical, whether mercury administration was discontinued or not. In selenium-protection and therapy studies, observable consequences of methylmercury exposure are abolished even when high methylmercury exposures occur in five-fold excess of selenium.

One selenium molecule will take care of 5 mercury molecules. In one study, two rats received an adequate amount of selenium. One received no mercury and the other received a toxic amount of mercury. Both rats did very well [24].

The importance of eating fish as a source of selenium to health

Many diseases are linked to the lack of sufficient selenium in our diets. Selenium is important for enzyme activities in the brain and endocrine tissues, has highly a significant but less understood role in preventing certain types of cancer, and improving many aspects of immune system health. Deletion of this mineral from the diet results in severe neurological issues such as mental retardation and delays in development.

The presence of methylmercury is fairly high in the gulf region of the U.S. By coincidence, selenium concentrations are highest in water ways including lakes, rivers, oceans, seas, canals, with the Gulf of Mexico being one of these regions. Although methylmercury in these areas is higher than other places, so is selenium. Robert Disney points out, “Nature knows what it’s doing.”

Selenium is one of the lesser common minerals found on earth, but is critical for sustained function of 20-30 important enzymes needed for biological functions. Brain, nervous system function, and protection against oxidative stress are just a few of the important functions of selenium in our bodies.

Maternal methylmercury exposure in excess of selenium intake

Conventional health information recommends pregnant women avoid fish due to mercury content. These recommendations fail to take into account the presence of selenium in fish which can counteract the effects of mercury.

Eating fish is important for the development of the fetus because they considered brain food for human beings, not only due to its content of Omega 3 essential fatty acid DHA but selenium as well. Selenium also has a therapeutic and protective affect against growth impairment (a sign of mercury toxicity). A deficiency in selenium during pregnancy can lead to developmental issues in the fetus. In various studies involving humans, children’s brain health, behavior, mood, and learning were shown to greatly benefit from eating fish.

From the Energy & Environmental Research Center, the University of North Dakota, and Dr. Nicholas Ralston:

The Conventional Hypothesis states that maternal methylmercury exposures from seafood consumption are directly associated with adverse neurodevelopment outcomes in children.

The following table illustrates how out of eight countries where studies were conducted, the last four done in the Seychelle Islands, the U.S., the U.K, and Denmark show children benefitted from fish consumption. Results of these major human studies of maternal methylmercury exposure do not support the conventional hypothesis, and the most appropriate studies are in conflict with it.

Another hypothesis, the Selenoenzyme Inhibition Hypothesis, states that maternal methylmercury exposures in excess of selenium intakes are directly associated with adverse neurodevelopment outcomes in children.

The following table shows how the Selenoenzyme Inhibition Hypothesis is consistent and shows nothing in conflict with the results of the same studies conducted in eight countries to determine whether maternal methylmercury exposure in excess of selenium intake was associated with adverse child neurodevelopment outcomes.

In the publication Mercury-Dependent Inhibition of Selenoenzymes and Mercury Toxicity by Dr. Nicholas Ralston, Alexander Azenkeng, and Laura J. Raymond, there is an in-depth analysis and discussion of how “Selenoenzymes prevent and reverse oxidative damage in the brain and neuroendocrine system, but these enzymes are vulnerable to irreversible inhibition by methylmercury (MeHg).

Selenoenzyme inhibition appears likely to cause most if not all of the pathological effects of mercury toxicity. This biochemically based understanding seems to explain why certain tissues are affected by mercury, why the latency effect is unique to mercury poisoning, why selenium status is inversely related to mercury toxicity, why fetal exposures are so much more harmful than adult exposures, and why prenatal inhibition of selenoenzymes by high MeHg results in sustained loss of their activities.”

These results reinforce that maternal exposure to mercury which exceed selenium intake in the diet lead to brain and neurological disorders for unborn children.

Selenium for detoxification and as an antioxidant

Not only does selenium promote detoxification which benefits the immune system to aid in the removal of heavy metals such as methylmercury from the body, it also acts as an antioxidant which has strong anti-cancer effects.

In the early 1970s, scientists discovered that Selenium is incorporated into proteins to create selenoproteins, important enzymes that act as antioxidants (they destroy free radicals and prevent cellular damage which can lead to cancer), and also regulates thyroid function.

According to Robert Disney, symptoms of metal toxicity line up with what scientists have observed in an organism with selenium deficiency. Selenium sequesters heavy metals such as mercury, cadmium, and lead and prevent them from embedding themselves into cells. Various metals can react with other compounds, and take selenium away from where it is needed. When they bump into each other, it causes the selenium to not be used where it is needed in the body [24].

That’s where eating fish comes in: of the top sources of selenium identified by scientists, 17 of those are from ocean fish and provide enough to pull out mercury and also provide the organism with enough selenium to maintain health.

Studies from the Faroe Islands showing where mercury toxicity was an issue from eating seafood included samples of human hair taken from individuals consuming seafood included a large amount of pilot whales. In other words, the bodies of these whales contain far more mercury than selenium. In general, the majority of ocean fish have more selenium than mercury. So while it is best to avoid eating larger fish, eating what you catch on a pole should be considered a safe practice.

How much selenium do we need for good health?
The average person receives about 65 micrograms of Selenium per day. Two-hundred micrograms is considered optimal, while 400 micrograms is the maximum allowable daily dose. Although too much selenium is toxic to the body, most people are deficient due to the nature of our processed diets and depletion of selenium in our soils.

Where is selenium found in the world?

In the modern world, consuming too much selenium is very rare. The most abundant plant-based source of selenium in the world comes from Brazil Nuts. Areas including South America, most of Northern Europe, North America, Africa, Russia and China have little or no selenium in the soil. Geographically speaking, a lot of selenium is found on hilltops and higher regions in the geography, and it is always flowing downhill due to erosion and other natural sources (wind, rain).

The most abundant plant-based sources of selenium in the U.S. are in the mid-western states such as Nebraska, Arkansas, northern Iowa, and some lower mid-western to southern states such as Mississippi, eastern Kansas, northern Missouri, and parts of Wyoming and Montana where a large majority of grains are grown.

Due the industrial processing of grains and nuts, lack of adherence to traditional preparation methods such as soaking, sprouting, and fermentation of those foods to improve digestibility of nutrients, poor digestive health of the average person, and increasing damage to soil due to toxic, commercial farming methods, these reasons collectively contribute to why our population actually absorbs much less selenium than is needed for health.

To be able to absorb selenium from grains and nuts, the source of the food such as organic instead of conventional, healing the digestive tract with nutritious foods, and proper preparation is essential.

According to Dr. Lawrence Wilson, M.D., “The soil conditions everywhere on earth in regards to selenium availability are worsening due to several factors. First, acid rain has been created from increased levels of sulfur and nitrogen in the atmosphere (due to pollution). This changes the PH of the soil, making it more difficult for selenium to bind to plant roots. Additionally, heavy metals such as mercury in rainfall quickly bind to selenium and form insoluble compounds Both of these problems lower the amount of selenium entering the food chain.” These are more reasons why consumption of fish as a source of selenium is so important.

Symptoms of too little selenium include: cancer, neurological and brain issues, heart disease, fatigue, stunted growth, high cholesterol, compromised immune system function, liver impairment, pancreatic insufficiency and sterility.

Symptoms of too much selenium include: arthritis, brittle nails, bad breath, hair loss, irritability, liver and kidney problems, tooth loss, jaundice.

Read about how much fish we should eat.

About Our Guest Author

Raine Saunders is a writer, researcher, blogger, and Holistic Health Coach with an emphasis in the GAPS protocol. To read more, visit www.agriculturesociety.com where she blogs about real, traditional food, sustainable farming, food politics, eco-friendly choices and recipes, natural remedies, and more.

This document was prepared for the Green Pasture Products website, producers of the only raw, traditionally fermented cod liver oil on the market. Green Pasture’s signature product Blue Ice Royal combines the superior nutritional benefits of fermented cod liver oil with high vitamin butter oil (the “Activator-X” component discovered by Dr. Weston A. Price in his travels during the 1930s which was virtually missing from modern, processed diets) to bring you a food that contains the most natural and potent forms of Vitamin D and also Vitamin A for optimal health benefits and support.

Children, pregnant and nursing moms need the immense nutritional benefits found in nutrient-dense foods like fish (and other seafood). It is easy to become concerned about warnings and other cautions issued by health authorities about heavy metals like mercury. Hopefully this research can put your mind at ease about this controversial topic and enable you to make decisions you are comfortable with for your family’s health.

Raine explains, “Every time I post this document somewhere, I get comments from those who are also concerned about radiation. My response is that we are exposed to radiation in our environment everywhere due to situations like the event that happened in Fukishima in March of 2011 and existing nuclear facilities. Most foods are said to be contaminated by radiation, so if we were to stop eating fish, should we then apply that same philosophy to all other nutrient-dense foods such as raw milk, grass-fed meats, and pasture raised poultry?

Fermented foods, bone broths, and other traditionally prepared foods from healthy, safe sources can provide our bodies protection against radiation damage.

For more information, read:
Safe Space Protection

Protection from Radiation Sickness, WAP, Dr. Thomas McCowan (right now WAP is having site access issues again, which I’m sure you are aware of, hopefully this will be resolved ASAP)

Radiation and Community Illness, WAP Joette Calabrese

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23.  Robert Disney, Environmental Scientist, personal interview, February, 2012.

Robert Disney, Environmental Scientist, Mercury in the environment/Emerging waste water contaminants, live presentation, Weston A. Price Wise Traditions Conference, November, 2010.

How do you feel about eating fish and/or shellfish?! Did this article change your mind?