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Did you know that a recent US geological survey found methyl mercury in every fish sampled from 300 small streams? Two-thirds of these fish exceeded safe consumption levels established by the US Environmental Protection Agency (EPA). Fish sampled from lakes and reservoirs had an even more appalling turnout: more than half exceeded acceptable methyl mercury levels.
Methyl mercury is the form that mercury takes after it has been released into the atmosphere through burning – such as the mercury burned off in coal mines – and settles onto organic materials, binding to the organic molecules. This form of mercury is much more dangerous than the “quicksilver” mercury found in thermometers that we used to play with as kids. While technically methyl mercury is the form of mercury we are discussing in this article, for ease, I’ll be referring to it simply as mercury.
The mercury levels have gotten so high that 15% of all newborns in the US have dangerous levels of mercury in their blood, putting them at risk for neurological defects, according to the EPA in February of 2004. In that same year the FDA put out a Public Health Advisory stating that women of reproductive age should not consume swordfish, shark, mackerel, or tilefish due to levels of mercury deemed unsafe for human consumption.
Despite conflicting information around radiation levels in the Pacific Ocean from the Fukushima Daiichi nuclear disaster, most reports indicate levels here in the states and Hawaii are much less than expected. That said, we must be careful regarding the quantity, source, and type of fish we consume.
So, what are your options if you love eating fish and want to keep getting the health benefits of this nutrient-rich protein source? Read on to find out my 5 Safety Rules for Eating Fish, as well as the symptoms of mercury toxicity and what to do if you have it.
5 Safety Rules for Eating Fish
- Limit fish consumption to once a week
- Choose the right kind of fish
- Eat more chlorella, cilantro, and garlic to chelate mercury from your system
- Become a good digester (our digestive pathways are our detox pathways)
- Cleanse regularly
Underestimated Dangers of Mercury
The term “Mad Hatter” was used to describe the behavior of hat-makers contaminated with mercury in the 19th century. At the time, a mercury solution was used in the curing of animal pelts. Poor ventilation meant the hatters were breathing in the fumes, and residues of this highly toxic metal accumulated in their bodies.
Mercury accumulates in the fat, liver, kidneys, brain, and blood. Even very low levels can affect the development of a fetus or infant, as methyl mercury has been shown to cross the placenta and affect the developing brain before birth. (1) High levels may cause kidney, brain, mood, heart and genetic concerns. (1)
To boot, research conducted in the past year has shown that harmful effects occur at lower levels of mercury exposure than was previously recognized. In response, authorities that have been involved in these studies posit that a revised definition of tolerable mercury intake is needed. And while there is no clear line between safe and unsafe levels of mercury exposure (risk generally rises as exposure rises), many of the safety standards for mercury content floating around today are based on research done more than a decade ago. We may see the government recommendation for safe quantities of exposure getting lower and lower as more research comes in. (2)
Where is it coming from?
Nowadays, coal mine clouds blanket most of the United States. Seeping from coal and oil-fired electric plants, their smoke infiltrates the air, as well as our streams, lakes and rivers. Thus, humans and other living beings are exposed to mercury through the air we breathe and the water we drink—it even laces the best organic foods. We really cannot avoid this exposure. Amalgams and vaccinations are also sources of mercury exposure that need to be evaluated. The major source of contamination for humans, however, is the consumption of mercury-laden fish and seafood.
Are you a sushi lover? In 2010 the New York Times tested 44 pieces of sushi: they found 8 pieces that exceeded the legal action limit set by the FDA of 1.0 parts per million (ppm)—meaning they were not safe for consumption. That same year, gotmercury.org did an undercover survey of fish being sold in sushi bars, supermarkets and farmers’ markets. The results were unsettling:
- 1 in 3 fish purchased in supermarkets exceeded the legal action limit set by the FDA. (1)
- Almost 20% of tuna sold in sushi bars were over the legal action limit. (1)
- Almost 20% of all sushi sold was over the legal action limit. (1)
- Out of 184 samples of fish taken, all had detectable levels of mercury averaging 0.5 ppm. (1)
Mercury Toxicity in Humans
Symptoms of low-level mercury can include:
- Hair loss
- Memory loss
- Mental instability
- Compromised immunity
- Numbness in arms and legs
- Learning disabilities
- Central Nervous System Damage
- Reduced motor skills
- Depression, anxiety, and other psychological effects
How do you determine your mercury levels?
If you are an avid fish eater and have any of the symptoms mentioned above, get a blood test to confirm your mercury levels. Also, gotmercury.org has a mercury finder that can help determine your potential risk according to your fish consumption (note that this is not an accurate alternative to a blood test). It is also a great website to learn about the impact of mercury on wildlife and the environment.
Can mercury be removed?
If you have mercury poisoning, stop eating fish! Studies show that once we stop eating fish the mercury levels in the blood come down on their own. But mercury has a proclivity to store in the fat cells and in the brain, liver, and kidneys. So while the blood might show reducing levels, it may still be hiding out in the fat cells. Thus, it is important to help chelate this stored mercury out of the fat cells and out of the body.
Chelation: the process of removing heavy metals from the bloodstream by means of a chelate: a food or nutritional agent that attaches and removes heavy metals from the body.
The best food-based chelators for mercury and other toxic metals are garlic, cilantro, and chlorella. If you insist on eating fish or are concerned about mercury toxicity, include these foods regularly in your diet.
- Garlic has been shown to be beneficial in the management of heavy metal toxicity—especially lead, cadmium, and mercury.
- Cilantro may suppress the deposition of lead and appears to aid in removing mercury from aqueous solutions.
- Chlorella is a green algae that may uptake toxic metals and thereby decrease their re-absorption from the gut.
Sometimes it is difficult to eat these foods consistently enough to reduce your heavy metal load. Oral chelators such as EDTA & DMSA, Alpha Lipoic Acid, and N-Acetyl Cysteine (NAC) are considered natural chelators of heavy metals.
Become a Good Digestor
The digestive system is the body’s primary means of getting nutrients in and waste out. One of my favorite measures of whether we are good digestors is the status of the elimination and tolerance of foods. If you have chronically loose or dry (constipated) stools, or can’t digest hard-to-digest foods such as wheat, dairy, soy, nuts, or fatty foods, you may not have the digestive strength you need to be a good digestor.
Ayurvedic cleansing has been shown to support the natural detox process of heavy metals. Of course, Ayurvedic cleansing always makes great effort to reset digestive strength first, before pulling toxins back in to the blood stream for removal. Essential fatty acids (EPA and DHA) from fish oil can be a safer option for reaping the benefits of fish without eating fish of unknown quality, if you can verify the source of the supplement.
Protect Yourself and Your Family: A Consumer Guide to Mercury Levels in Fish
The list below details the amount of various types of fish that a woman who is pregnant or planning to become pregnant can safely eat, according to the Environmental Protection Agency. People with small children who want to use the list as a guide should reduce portion sizes. Adult men and women who are not planning to become pregnant are less at risk for mercury exposure but may wish to refer to the list for low-mercury options.
Protect Yourself… and the Fish!
Certain fish, even some that are low in mercury, are poor choices for other reasons, most often because they have been fished so extensively that their numbers are perilously low. These fish are marked with an asterisk.
This list applies to fish caught and sold commercially. For more information about fish you catch yourself, check for advisories in your state.
LEAST MERCURY — Enjoy these fish:
Mackerel (N. Atlantic, Chub)
MODERATE MERCURY — Eat six servings or less per month:
Bass (Striped, Black)
Croaker (White Pacific)
Tuna (canned chunk light)
Weakfish (Sea Trout)
HIGH MERCURY — Eat three servings or less per month:
Mackerel (Spanish, Gulf)
Sea Bass (Chilean)
Tuna (canned Albacore)
HIGHEST MERCURY — Avoid Eating:
Fish in Trouble!
These fish are perilously low in numbers or are caught using environmentally destructive methods. To learn more, see the Monterey Bay Aquarium and the Blue Ocean Institute, both of which provide guides of fish to enjoy or avoid based on environmental factors.
Farmed fish such as farmed salmon may contain PCB’s, chemicals with serious long-term health effects.
The data for this consumer guide comes from two federal agencies: the Food and Drug Administration, which tests fish for mercury—and the Environmental Protection Agency, which determines safety of mercury levels for women of childbearing age.
The consumer guide is categorized according to the following mercury levels in the flesh of tested fish:
LEAST MERCURY = Less than 0.09 parts per million.
MODERATE MERCURY = From 0.09 to 0.29 parts per million.
HIGH MERCURY = From 0.3 to 0.49 parts per million.
HIGHEST MERCURY = More than .5 parts per million.
4. Sea Turtle Restoration Project: seaturtles.org
5. Natural Resources Defense Council: NRDC.org