I’ll never forget that moment. I was rummaging through frozen food left over from my sister's old roommate, hoping to find some illustrious hidden treasure crystallized in its still-edible form eons later, due to the underappreciated magic of sub zero temperatures. Then I saw it... a wild-caught frozen swordfish filet.
Now, I knew swordfish was one of *those* fish high in mercury - one of the ones often listed on restaurant signs warning about mercury consumption and pregnancy risk. (Always alongside tilefish and shark… because who eats shark?) On principle I’d only been consuming (mostly) tilapia, cod, shellfish, sustainably-raised and monitored barramundi, and the occasional tuna at restaurants. (More on tuna in a bit!) That said, my recent discovery of fish adoration marked my re-entrance to LA, and I was enthralled by the lingering tastebud orgasms I’d experienced with chilean sea bass and opah. I wanted to try #allthefish #allthetime. How bad could that be? One swordfish (or one opah or one Chilean sea bass) couldn't be so bad, right?
And one became three.
But did you know a single piece of swordfish can yield the equivalent amount of mercury as hundreds of pieces of salmon?
But I'm getting ahead of myself.
The shiny metal known as mercury comes from the Greek word for “liquid silver”: hydrargyrum, which is also where its element symbol Hg comes into play! Also known as “quicksilver” for its speed, Mercury hearkens to the appropriately named swiftest celestial planet in our solar system, as well as the chief Roman god.
In the environment, mercury exists in three main forms: elemental (a vapor), inorganic (mercuric mercury) and organic (methyl mercury and ethyl mercury). Around one third of mercury enters our atmosphere thanks to natural sources like volcanic eruptions, with the rest coming from man-made sources like coal mining and fossil fuels, and even creepy things like medical wastes and cremation (which accounts for 26% of the US’s atmospheric mercury). This atmospheric mercury filters down into our waters and is transformed into highly toxic organic mercury (which is readily absorbed in our GI tract), discussed in the fish section to come!
Exposure to mercury over time, or even in small doses - from the many various sources (the water, fish and other food, soil, air, fillings, etc.) can lead to an overwhelming host of detrimental health effects. One of the most toxic substances known to mankind, mercury can have devastating effects on the body. While no single mechanism of action can explain its shockingly detrimental effects, we do know mercury encourages a torrential downpour of oxidative stress by interfering with our cells’ redox homeostasis (our cells’ natural control of stress factors) and glutathione production (our body’s innate master antioxidant). It also can interfere with calcium regulation, mess up membrane potential, affect protein synthesis and amino acid pathways, damage mitochondria, oxidize fat, and so much more! And because mercury is both water and fat soluble, it can easily cross the blood-brain barrier and do extreme damage to the brain and nervous system.
For starters, mercury can literally poison our nervous system, demyelinating cells and encouraging neuronal and autonomic dysfunction, resulting in mood changes (irritability, anxiety, etc.), fatigue, headaches, brain fog and slower cognitive function, incoordination, and even hallucinations and death. In The End of Alzheimer's: The First Program to Prevent and Reverse Cognitive Decline, Dr. Dale Bresden links mercury to cognitive decline. This makes sense, since mercury harbors an affinity for fatty tissue, and the brain is our body’s fattiest organ, composed of around 60% fat. Even though the brain uptakes mercury slower than the rest of the body, studies nevertheless show that around 10% of the body’s mercury burden tends to reside in the brain, with concentrations often reaching up to 6x the amount in the blood.
Mercury can also injure the heart, leading to cardiovascular problems, hypertension, and altered endothelial function. Other negative health effects include GI problems, pulmonary and skin issues, reproductive and immune system toxicity, genotoxicity, renal issues, and so much more.
In fact, the phrase “Mad Hatter” likely comes from the fact that, back in the day, hatters in England used mercury in the hat-making business… and would literally go mad!
Sources Of Exposure
While the body does naturally excrete mercury, it has a fairly long half-life of around 2-3 months. I typically avoid absolute statements, but it’s pretty safe to say that everyone has some amount of mercury in their system, thanks to modern circumstances. That said, a person’s diet, environment, and genetics can influence how easily he or she detoxes mercury, and many people may be more prone to storing it than others. You can suspect mercury toxicity problems if you’ve encountered any of the following factors:
- BIRTH: If your mother had extremely high mercury levels, you likely “inherited” mercury at birth. Studies have found that the levels of mercury in the umbilical cord tend to be higher than in the mother’s blood, up to twice as much!
- AMALGAMS: If you’ve had mercury fillings - and especially if you had them removed by a dentist not literate in proper removal - you could have been exposed to detrimental mercury levels.
- FISH: If you’ve consumed high mercury fish, or even moderate amounts of low mercury fish, pay heed! Our GI tract tends to absorb around 90-100% of mercury from food.
- GENES: Various genetic tendencies may make you more susceptible to heavy metal toxicity. The fact that different people can vary vastly in their response to the same metal exposures, insinuates the degree of toxic effect is individual, likely involving certain single-nucleotide polymorphisms (SNPs) which can influence how your body handles and detoxes metals. (I say “can”, not “do,” because environment and epigenetics are equally important!) These can include:
- Genes which code for the glutathione S-transferase family (GSTs), which help regulate the glutathione detoxification system and influence how it absorbs, distributes, metabolizes and excretes heavy metals. Those with a tendency for a more efficient glutathione system may better process and excrete mercury, while those with less than stellar functioning systems may retain more mercury.
- Genes which may influence the body’s internal chelating proteins rich in cysteine, known as metallothioneins (MTs).
- The APOE gene - famous for its role in Alziemiers - may play a role in the body’s potential mercury burden.
- Selenoproteins are intrinsically involved in thwarting mercury toxicity, so genes involved in their coding may also play a role.
- VACCINES: Vaccines containing thimerosal, which is used as a preservative, feature 49.6-percent ethylmercury mercury. These may include vaccines for HIB, hepatitis B, DTap, as well as others. A 6 month old child receiving one of these vaccines could net mercury levels greater than 1.0 μg per day, above the “safe” exposure levels set by the FDA. (As if there were “safe” mercury levels!).
- LOCATION: If you live near a former mercury mining site or coal plant, or in a building with mercury latex paint (removed from paint manufacturing in 1991 but still available), you may be at risk for mercury toxicity.
- OTHER EXPOSURE SOURCES: A person can also be exposed to mercury via pesticides, pollution, cosmetics (numerous skin-lightening creams and antiseptic facial products), laxatives, teething powder, antiseptics, thermometers (though the liquid form of mercury is not very readily absorbed), among others.
Guess what organ boasts the highest exposure rate and absorption of heavy metals, real-estate wise? If you guessed our skin - you're right! Unfortunately, we often slather our skin in toxic heavy metals via our skincare. Many skincare products (such as skin whitening creams) contain mercury, while makeup is often tainted with heavy metals, particularly lead and asbestos. Ironically, this may be more likely for those trying to be "kinder" to their skin with mineral based makeup - since these mineral sources are often a source of heavy metals!
I encourage you to contact your makeup brands, to ascertain if they check for heavy metals, and how often. Since metal concentrations can vary from site to site, deposit to deposit, supply to supply, consistent testing is key! My obsession with finding heavy-metal free skincare, is what lead me to Beauty Counter. Beauty Counter not only formulates beautiful nontoxic makeup and skincare products, but they regularly test for heavy metals. Check out BeautyCounter.com/melanieavalon - I swear you'll never look back!! (I personally love the mascara, lipsticks, and eyeliner!)
Mercury Toxicity Symptoms
While the 250+ symptoms of mercury can match a host of other potential diseases and root causes, they may include:
- Neurological: brain fog, mood swings, anxiety, irritability, decreased cognitive function, memory problems
- Physical: tremors, weakness, headaches, excessive salivation
- Auditory/visual impairment
- Loss of coordination
- Numbness in the hands and feet
MERCURY AND FISH
“Everyone” knows fish is a source of mercury… but why fish and not, say, turkey or elk? It all goes back to the source. Thanks to industrial coal burning, mercury prevails in the atmosphere. This mercury then filters into the water system and oceans through rain and runoff. While inorganic mercury is not easily absorbed by humans, bacteria in the ocean actually transform it into a highly toxic and absorbable organic form called methylmercury. And since fish are swimming in these waters, well...you get the picture! (Interestingly, elemental mercury can also potentially be transformed into organic methylmercury by our gut bacteria.)
Organic mercury from fish is very easily absorbed in the GI tract (around 90-100%!), and then typically excreted via the liver through the bile. Its half life is long and slow (around 2-3 months), so the stuff not only tends to hang around, but build up! Organic mercury can also cross the blood-brain barrier, placenta, and central nervous system.
Mercury tends to accumulate as you go up the fish food chain. The critters at the bottom of the totem pole (think: shellfish), eat microorganisms like plankton, which contain mercury, accumulating minute amounts of mercury in their short lifespan. The fish that eat the shellfish acquire their mercury, while the fish that eat those fish acquire even more. Fish excrete mercury extremely slowly, so the further up you go, the worse things get, with larger, longer lived fish building up stores of the toxin over time.
To Fish Or Not To Fish?
Increased fish intake does correlate pretty consistently to increased mercury levels. For example, a 2007-2010 review of 10,000+ adults, found that those who abstained from seafood featured blood mercury levels of around 0.45, compared to 1.16 for those who ate seafood. Increased frequency of seafood consumption also correlated to increased blood mercury levels. (For example: 1-2 times a month netted an average of .7 μg/L, compared to 1.70 μg/L for those eating it more than 5x per month.)
Another study in 2006 looked at the effects of mercury levels in 63 pregnant Korean women who either were or were not counseled to reduce fish intake. At the start, the women ranged from 0.14 to 10.75 µg/L blood mercury levels, averaging 2.94 µg/L (though with such a huge range, I‘m not sure how pertinent that “average” is!) Initial mercury levels tended to correlate to fish intake (with more fish eating equating to more mercury). In follow-up studies, the blood mercury was significantly reduced in those counseled to curtail fish intake. This seems to be a pretty common trend. More fish = more mercury. Less fish = less mercury.
So, does this mean we shouldn’t eat fish? Not so fast! The arguments for eating fish are extremely high. Epidemiological studies consistently link fish consumption to decreased rates of disease, including cardiovascular disease, diabetes, inflammatory diseases, and even cancer. Fish tend to be rich in protein, minerals, trace elements, and vitamins - much more so than many other forms of animal products - including iodine, selenium, zinc, B vitamins, choline, and even vitamin D.
And while the cost/benefit of polyunsaturated fats may be debated in some circles, fish can provide omega-3s in their bioavailable form of DHA and EPA, unlike the plant based ALA. Because the human body is not very adept at synthesizing DHA and EPA from ALA, fish consumption can be a great way to support a healthy omega ratio, even if just to meet “minimums,” rather than saturate your body in omegas. (A topic for my NEXT blog post!)
Even the FDA - which once simply placed an upper limit on fish consumption due to mercury - has re-evaluated the matter. While upper limits still stand, the FDA now also advises a minimum fish consumption for pregnant women, to benefit fetal development - with an emphasis placed on low mercury varieties. That said, I believe their current endorsed lineup is not nearly discerning enough, given the varying levels of mercury within fish species, as discussed below!
And interestingly, some reports find that populations with increased mercury levels due to fish experience enhanced health nevertheless. The Seychelles Child Development Study found “no consistent pattern of adverse associations with prenatal MeHg exposure,” while a 2007 review concluded that “the beneficial influence of nutrients from fish may counter any adverse effects of MeHg on the developing nervous system.”
But perhaps most encouraging, while most studies tend to look at how reducing overall fish consumption reduces mercury levels, a more nuanced 2018 EWG study analyzed the effects of switching the type of fish to low mercury versions, rather than reducing fish intake overall. The researchers enrolled 20 US women with high mercury levels, who were then told to choose low-mercury fish per the EWG seafood calculator.
The results? After a mere three months, their levels had decreased by almost 30%! By simply switching to low mercury fish, rather than forgoing it completely, their bodies began naturally excreting the toxic substance, allowing the benefits of fish consumption, with mercury detox to boot! The researchers also suspected that, “The reduction of mercury levels would likely continue for those who make a permanent switch to lower-mercury seafood.”
In any case, mercury from fish is tricky, so what’s a health and fish loving guy or gal to do? I got you covered!
Measuring Mercury In Fish
A seemingly obvious but nevertheless noteworthy problem of mercury in fish, is the fact that you can’t see it. So you see 6 oz of salmon next to 6 oz of swordfish and you think… either way it’s 6 oz of fish: how big of a difference can it be? But if mercury were a color - like blue for example - the salmon might feature fading water droplets of pastel blue, while the swordfish might appear as an entirely opaque, dark stormy ocean, savvy?
Mercury in fish is measured in “ppm” or parts per million of mercury. Historically, the FDA has calculated the “safe” reference dose based on body weight over a week long exposure - equating to 0.1 microgram of methylmercury per kg of body weight per day. Numbers can get complicated, so I like using calculators like this one: http://www.obfocus.com/calculators/Mercury%20Calculator.htm
With the ppm perspective, you can start to see just how much mercury content can vary between fish species. For example, consider the FDA’s 1990-2012 charted levels of mercury in fish https://www.fda.gov/food/metals/mercury-levels-commercial-fish-and-shellfish-1990-2012 . According to the chart, tilapia averages .013 ppm, but ranges from no detectable levels to 0.084. Swordfish, on the other hand, averages 0.995 ppm, but ranges from undetectable to 3.22. While I raise an eyebrow at a piece of swordfish with undetectable levels (perhaps a test fail or universe anomaly?), in any case, this means the average piece of swordfish likely contains around 70x the amount of mercury as the average piece of tilapia! And if you take the worst case scenario - comparing the highest recorded mercury-laden swordfish to the lowest recorded mercury-laden tilapia - you get over 300 times more!
So eating that piece of swordfish, could be the equivalent of eating a year’s worth of daily tilapia!
In. One. Piece. Of. Fish.
Does that paint a clearer picture?
Furthermore, a 2012 analysis of the FDA’s findings actually found mercury levels to almost always be higher than those listed.
Factors Affecting Mercury In Fish
You truly can’t just look at fish species to gauge the amount of mercury, as a number of factors are at play, all of which I’ve used to ultimately generate my personal fish recommendations!
Farmed Vs. Wild-Caught
Historically, I was hardcore #teamwild caught. Then I got mercury poisoning and things changed real fast. Unfortunately, when it comes to wild vs. farm-raised fish, farm-raised fish tends to be lower in overall mercury content, thanks to the increasingly polluted nature of our oceans.
A fascinating 2012 study conducted a thorough analysis of 58 fish in 8 categories. It found that mercury was higher in the wild versions for all categories, averaging 2-12x more! Yikes! Wild seafood also had higher maximum average concentrations as well. Farmed fish also has the benefit of testing - at least in the case of producers who utilize sustainable raising practices and actively test for toxins.
The amount of mercury in any given species can also vary considerably. That piece of salmon may have almost no detectable mercury… or it might be tainted with enough to cause problems right off the bat! A 2012 analysis of 58 seafood items, found variances of 0.3-2.4 times the mercury between different studies. When you consider how potent mercury is in relatively minute amounts, these differences can have massive implications for the amount of mercury in fish.
A fish’s home body of water can also influence mercury levels. The Pacific ocean tends to be higher in mercury than the Atlantic (though Alaska may be an exception). Additionally, a U.S. Geological Survey and Harvard University study found that mercury levels have risen around 30% over the past two decades, and tend to rise the further north or south you go.
Some studies indicate mercury tends to accumulate in the muscle meat of fish, so a skin-on, full fish will likely have less overall mercury by weight compared to a boneless, skinless fish filet.
Mercury toxicity may also involve the complicated and debated role of the vital nutrient selenium. While a primary cause of mercury toxicity symptoms is often attributed to its sulfur and thiol binding activity - which allows it to cross membranes and distribute throughout tissues - mercury’s oxidative stress potential and organ injury may also involve its interaction with selenium.
Current research is revealing that mercury binds to selenoproteins in the glutathione-glutaredoxin and thioredoxin systems, permanently interfering with the redox status of the body, which works to implement protective homeostasis in regards to oxidative stress. Mercury’s toxicity and injury of this system can result in excess glutamate, skewed calcium levels, mitochondrial injury, slowed protein repair, peroxidation of fats, and even cell death. Mercury may both compete with sites requiring selenium for proper function, while also binding to selenium itself, resulting in a situation of severe damage requiring selenium to “fix it,” with no selenium to save the day!
This is often why many authorities and other figures now maintain that the mercury/selenium ratio is just as, if not more, important than the actual mercury content. They’ll often say that selenium can bind to mercury and render it “inert,” decrease mercury absorption from food, and also address the injured cellular redox environment. While this may be true, I’m hesitant about the implications of this view. While I do believe selenium is a vital nutrient protective in cases of mercury toxicity, and that we would likely benefit from consuming fish with high selenium content, I’m not certain a high selenium/mercury ratio is akin to a get-out-of-jail free card.
As a 2018 review of the matter noted, “There is conflicting evidence as to whether selenium increases or hinders mercury elimination, but increased mercury elimination does not appear to be a major role of selenium.” The fact that selenium could even potentially hinder mercury excretion - inert form or not - makes me even more hesitant. A review on chelation also noted that supplementing with selenium while chelating could be counterproductive, as the selenium could bind to the mercury in place of the chelators. Why do things always have to be so complicated?
That said, I do believe it’s likely safe to err on the side of more selenium rather than less, especially in a mercury toxic environment. As the 2017 Rethinking mercury: the role of selenium in the pathophysiology of mercury toxicity concluded, “The previously suggested ‘protective effect’ of selenium against mercury toxicity may in fact be backwards. The effect of mercury is to produce a selenium deficiency state and a direct inhibition of selenium's role in controlling the intracellular redox environment in organisms. Selenium supplementation, with limitations, may have a beneficial role in restoring adequate selenium status from the deficiency state and mitigating the toxicity of mercury.”
Can you reduce mercury with cooking? The research here is shockingly conflicting.
On the one hand, various cooking methods (like boiling and frying) may reduce mercury content via a few proposed mechanisms. While the metals themselves cannot “evaporate” or be broken down, high heat cooking methods may affect the metal complexes in foods - binding them to protein (if not already), or even carbs or fats, thus rendering them less assimilable by and reactive in the body. Cooking may also encourage the mercury to bind to water-soluble and/or uncoagulated proteins (if not already bound), and exit as free salts through the “run-off” juices, frying oil, boiling water, or stock.
To these points, Atta and others in 1997 found that baking and steaming reduced mercury in tilapia, with baking (which presumably “dries” out the fish more) having a greater effect than steaming (known for retaining moisture). Perello and others in 2008 found that frying and roasting decreased mercury in fish, while Ouédraogo and Amyot in 2011 found that boiling and frying reduced the bioaccessibility of mercury in fish by 40-60%. (This was notably increased by adding coffee and green tea to the boiling process - more on that in a bit!) They concluded that combining cooking with tea or coffee could reduce mercury bioaccessibility.
But wait! Before you resolve to cook away your #mercuryprobs, an overwhelming number of studies have found no reduction in mercury from frying, cooking or roasting fish. And while one study found cooking did decrease mercury content due to denatured proteins, another found the exact opposite: that cooking tended to increase mercury content. Some studies show trimming fish or removing their fat, frying or grilling, microwaving, and many other methods have no effect on mercury levels, while others report “considerable” reductions of heavy metals in food after cooking. Go figure. And a study on mushrooms (because… mushrooms!) found that blanching mushrooms reduced mercury by around 15% when fresh, and 35% when frozen, while pickling did nothing. Lastly, a 2010 study, found results all across the board, insinuating it may be more a matter of the initial amount of mercury in the actual fish, which can vary greatly even within species. (I feel like this is likely the case.)
The takeaway? Don’t turn to cooking to reduce the mercury content, since we don’t know if it hurts or helps, and it says nothing of the original mercury content anyways.
SAFE FISH EATING GUIDE!
Given all these factors, it is pertinent in my opinion to only consume species which tend to feature consistently low mercury levels, and then to research waters and the farm/wild methods beyond that. While this can seem like a lot on the proverbial and literal plate (and is also ever-changing based on environmental factors and company practices), I’ve got you covered, with my recommendations below! Also remember the previously discussed EWG study, which found that switching to low mercury fish - rather than removing fish completely - consistently led to very significant decreases in mercury levels after 3 months (by almost 30%!) And this was choosing from a more generous list of fish than my very selective list below!
THE YES! LIST
I’ve developed the recommendations below after hours of research, scrutiny, and cold-calling companies to drill them on their practices. As a result, I feel confident in endorsing the following fish sources, at least as of summer 2019. *Please note very important sourcing notes!*
SHELLFISH: Wild or sustainably-farmed, preferably from the Gulf of Mexico. (Interestingly, a 2014 review found no significant correlation between shrimp consumption specifically, and higher blood mercury concentrations.)
OYSTERS, MUSSELS: Ok, I don’t actually eat these myself, but they’re very high in nutrients, and very low in mercury.
SARDINES, HERRING, MACKEREL, ANCHOVIES: Again, I don’t fancy these myself, but these small fatty fish are super low on the fish totem pole, and low in mercury.
TILAPIA: Tilapia in general tends to test fairly low in mercury - even in this 2012 Seafood Hg Database’s revaluation of the FDA’s data. As of summer 2019, I can advocate sustainably farmed tilapia by Regal Springs (found in the frozen section at Costco under the Kirkland brand) , which tests below .03 ppm.
AUSTRALIS (only!) BARRAMUNDI: MUST be the Australis brand! Australis sustainably raises their barramundi in enclosed tanks of plant-based diets. Since an estimated 80-90% of a fish’s mercury content comes from their diet (with the rest coming from the water), this dramatically reduces the mercury content in the fish. I’ve spoken extensively with the company, and they’ve provided me with test results of a shockingly low 90% below Whole Foods’ standard of .02 (so around .002ish!) - essentially mercury free! For more on Australis, check out https://www.thebetterfish.com
THE MAYBE LIST
It’s hard to argue against the benefits of salmon (unless you’re a die hard Ray Peat fan - more on that in my next blog post!). Salmon tends to run lower in mercury levels compared to most fish species, and is readily available in stores, fish counters, and restaurants. It’s praised for its Omega-3 (hyphen added) content and other nutrients, such as vitamin D and astaxanthin. That said, please don’t assume salmon is mercury free! I advocate eating salmon only when you’re specifically craving it (embrace your body’s intuition!), and choose from the following when the occasion arises:
- Farmed Salmon (Gasp!): Sustainably-raised and tested, such as the certified brands at Whole Foods, or other brands who implement sustainable, nontoxic practices and test for mercury content. Due to these farming practices and monitoring, coupled with the fact that these salmon are often fed plant-based diets which minimizes mercury in their flesh (a fish’s diet accounts for 80-90% of their net mercury content), sustainably-farmed salmon is likely lowest on the salmon totem pole for mercury.
- Alaskan Wild Caught Salmon: While this is often a freebie in most low mercury lists, I still proceed with caution. Compared to the other options on the YES list, salmon can contain moderate or even comparatively high mercury levels, and a 2014 review found a 1.14-fold increase in the odds of mercury levels from salmon consumption. That said, for a health-supporting omega 3/6 ratio, wild caught is likely better than farmed, due to less overall fat content with a better omega ratio to boot. Wild salmon also notably achieves its rich pink color from the antioxidant anthoxanthin (unlike the artificial pink often coloring farmed versions.) Alaskan wild salmon tends to feature consistently low mercury levels as well, and native Alaskans who consume a boatload of it, have not shown any consistent patterns of mercury toxicity. In a study of 350+ Alaskan women in 2007, none had unsafe mercury levels, despite their Alaska fish-filled diet. (That said, I’d wager they’re more genetically adapted to mercury: just a hunch!)
- Canned Salmon: Due to production methods, canned salmon tends to be wild. Choose pink or sockeye canned salmon from Alaska.
- Contaminant Risk Ratio: A 2005 analysis studied and weighed the cost/benefit of salmon for its contaminants vs omega-3 fatty acid composition, and concluded that wild salmon in general yielded a better risk ratio. On the farmed side of things, salmon from Chile and Washington State provided the best risk ratio, while the worst was awarded to Faroe Islands and Scotland.
Other Maybe Fish
- If you DON'T have mercury toxicity problems, I think occasional consumption of other low-mercury species might be ok, but I can’t endorse them 24/7. Proceed with caution! These include: Atlantic cod, catfish, pollock, sole, farmed rainbow trout, etc. Please reference the EDF Seafood Selector for more information: http://seafood.edf.org/
THE NO! LIST
Tuna is a complicated one, likely because it can vary so much in size. While all salmon is likely low mercury (at least comparative), all tuna is not. According to the EWG, a single weekly serving of albacore tuna, for example, would result in dangerous mercury levels in a pregnant woman. In fact, a 2011 Consumer Reports review found that all sampled tuna featured moderate to very high mercury levels, while the FDA has shown some tuna rivals mercury levels of shark and swordfish - yikes! I’m particularly nervous about the government's recommendations of canned light tuna as a “best choice” and albacore tuna as safe for weekly consumption. I would instead encourage you to avoid tuna, to be on the safe side.
In any case, from best to worst, here’s how it’s currently looking:
- Canned Chunk Light Tuna: Canned “light” tuna is likely the safest, as it’s typically made from the lower mercury skipjack species (though it may feature some higher mercury albacore), and features levels of around .12 ppm of mercury, according to the Environmental Defense Fund. That said, a 2006 Consumer Reports analysis found that some light-tuna samples featured more mercury than some white tuna samples, as discussed next.
- Canned White Tuna: Canned white tuna predominantly features the albacore species, yielding higher mercury levels of around 0.32 ppm of mercury according to the Environmental Defense Fund, and possibly even higher average levels above .4 and reaching up to 0.774 ppm, according to Consumer Reports. Additionally, added labels on canned tuna like “gourmet” may indicate other higher mercury tuna species discussed below.
- Tuna Filets And Steaks: Tuna filets and steaks are typically from large predatory species like yellowfin (“big eye” or “ahi”) and bluefin, common as tartar and tuna steaks in restaurants. Avoid!
Fish To Avoid At All Cost
Please learn from my mistakes, and never consume these fish. Ever. Yes, one piece can hurt. This is not a case of “moderation in everything”, because these species are not moderate in mercury, see? Just imagine that eating ONE piece of swordfish, might be like eating hundreds of pieces of salmon. Please step away!
- King Mackerel
MERCURY IN OTHER FOODS
Besides fish, do you need to be concerned with mercury in other food sources? It’s true that meats like poultry can contain organic mercury, if they were fed fish products, as well as pesticides, fungicides or insecticides. (Yet another reason to always choose pasture-raised, organic!) Thankfully, plants and vegetables tend to feature very low levels of mercury. This is due to mercury’s affinity for humic substances, which mean its bioavailability in the soil and capacity to infiltrate plants tends to be limited.
While amalgams may be cosmetically pretty for our teeth, they are not so beneficial for our health! Dental amalgams often contain a restorative material consisting of around 50% elemental mercury, accounting for around 10% of mercury consumption worldwide! Their safety has never been tested in the US, and many studies conclude they are likely a source of toxicity. In autopsies, dental amalgams have been identified as a major source of mercury deposits in the human body, while the World Health Organization in the 1990s identified dental amalgams as the most significant mercury exposure source, leading to exposure levels exceeding maximums set for air, water, and food.. The average intake of elemental mercury vapor from amalgams may range anywhere from 3.9-21.0 μg a day.
While mercury bound in amalgams may be inert if it stayed there in the amalgam, the mercury eventually vaporizes, with 80% being absorbed by the body, including in the brain.
Before you jump on the get them out now train, it is vital that you have your amalgams removed by a dentist or surgeon highly schooled in proper removal. Otherwise, you run the very definite risk of intensely poisoning yourself in the removal process!
TESTING MERCURY LEVELS
A variety of methods can be utilized to ascertain one’s current status of mercury toxicity, each with their potential pros and cons, as well as implications of total body burden. While various tests can often readily confirm recent acute exposure, the more subtle long term exposure responsible for many chronic health issues can be harder to “find” via these tests, especially since this build up may occur in a situation where the body is actively storing mercury, but not readily excreting it. A person may harbor an extremely high total mercury burden, but may test below EPA or other governing body reference ranges. On the flipside, provoked challenge tests can create misleading false positives as well.
Blood tests measure the amount of mercury actively circulating in the blood, with safe reference range maximums typically placed at <10 ng/mL. These tests are most reliable for recent mercury exposure, as the body quickly attempts to remove mercury from the bloodstream, excreting it via the liver or kidney, and/or storing it in bodily tissues. High levels are a bad sign, (especially in the absence of any recent acute exposure), as they can indicate the total body burden may be quite high. That said, a low blood mercury result does not necessarily correlate to total body burden, which could still be quite high.
Mercury in the urine has been filtered via the kidneys. Baseline urine levels can be tested to see if a mercury overload is present, whereas challenge tests (more on that in a bit) use provoking agents to purposely pull mercury from the tissues, which is then excreted via the kidneys. Urine tests may be a good gauge for acute elemental and inorganic mercury poisoning, but perhaps not so much for organic mercury, such as that found in fish. An unprovoked urine test is typically not a good indicator of total body burden.
Provoked urine challenge tests are often considered the gold standard for testing. In a challenge test, the participant ingests a chemical chelation agent (often via an IV or push) such as DMPS or EDTA (discussed in great detail below), and then their urine is collected over the next few hours, to see how much mercury is “pulled” out and excreted via the kidneys. Challenged urine test results are often compared to non-provoked reference levels, which can be misleading, making it appear like a person is “mercury toxic,” when they may in fact not be, encouraging unnecessary chelation. That said, continued chelation with urine testing, if interpreted by a qualified practitioner, can arguably paint a fairly clear picture of the mercury detox progress.
Mercury ends up in the feces after being detoxed through the liver and bile. It can be used to detect recent organic mercury, such as from fish, but isn’t as common a test. HAIR: Hair tests for mercury are tricky. Some advocate they imply total body burden, with high levels being a problem, whereas others argue low levels are potentially more problematic, since they may indicate the body is storing, rather than excreting, metals. In any case, the Environmental Protection Agency advocates a mercury hair guideline of 1 ppm. (In a 2016 study of 254 women, the EWG found almost one third exceeded this.)
If you’re particularly mercury toxic, simply stopping your source of exposure (especially if dietary), may not lead to an instant recovery. Even with the source removed, if you have a high body burden, these metals can continue to cause issues. So now that I’ve possibly got you more scared of mercury than Jason, what’s a poor soul to do? Enter the nebulous world of chelation! Because no better way to eradicate an invisible substance that may be ruining your life, then with hotly debated methods of natural and chemical compounds that may pull these metals from your system… or make things worse in the process.
But have no fear! Here’s all the info, so you can make the best decision for your health!
What Is Chelation?
The word “chelation” comes from the Greek word “chele,” which refers to the claw of a lobster. This is appropriate, since in the chelation process, compounds known as chealtors “chelate” (tightly bind) to other elements - like the firm group of a lobster!
To be more specific, chelating compounds are organic or inorganic molecules which mobilize and bind to metal ions to create more stable, less toxic complexes with ring-like structures called “chelates.” These bounded metals can then be excreted relatively easily by the body, primarily through the kidney via the urine, as well as through the liver via bile. Water soluble chelators may be more primarily excreted via the kidney, whereas fat soluble cheltors may be more excreted via the bile.
Chelation can occur with both natural and pharmaceutical compounds, all with their various costs/benefits. With pharmaceutical chelation, the agent tends to bind directly with metals. Natural chelation can also occur in the body, when glutathione and other molecules bind to metals, forming compounds to be excreted. Various foods and supplements can also chelate metals, as discussed below.
As a final note, metals can also be released from various life factors, such as trauma and stress, hormonal conditions like menopause, and particularly pregnancy. In fact, women can lose a shocking amount of their metal burden via the placenta - which is quite unfortunate for the newborn! Fasting can also release metals from fat stores, which may explain in part why some people experience intense “detox” symptoms while fasting.
When undergoing pharmaceutical chelation, the patient ingests a chelating substance (often via IV, but also potentially orally as well), which mobilizes and binds to heavy metals. These are then eliminated (with the metals bound intact!) mostly through the kidneys and urine. A major pro of pharmaceutical chelation is the chelators can grab a substantial amount of metals and usher them out of the body rather quickly. (Typical IV half-lives range around a few hours). On the flipside, chelators can (and do) grab onto other beneficial nutrients as well, and the whole process can be taxing on the body. Redistribution of metals can also be a concern.
The chelation procedure usually starts with a “Challenge Test”, in which the patient ingests the chelation agent, and collects their urine for the next ~6 hours. This urine is then analyzed for heavy metal content, to see how many metals were pulled out and excreted. (Doctors Data is a recommended lab commonly used for this.) The patient can then work with a knowledgeable practitioner from there, to continue IV treatment in rounds of the appropriate time and dosing, to pull out increasingly more metals, and lessen the body burden.
Some important notes about pharmaceutical chelation:
- PROVOKED VS. UNPROVOKED: Provoked chelation test results (meaning a chelator was used prior to the test) are often compared to average metal excretions from standard, “non provoked” conditions. This can make a patient look like they have way more metals than the average person. It can be helpful for a patient to perform both a provoked and unprovoked urine analysis, in order to see how many metals are being excreted without chelation.
- CHOOSING AN AGENT: Individuals may respond differently to the various chelation agents (ie: EDTA, DMPS, DMSA). Some practitioners like to test multiple agents to see how the patient responds. That said, please see the individual sections below for more information on each chelator, particularly its affinity for various metals.
- THE PROCESS: The chelation process can be slow, long, and shifting. When initially undergoing chelation, the chelating element tends to “grab” the metals of the highest burden. As progressively more chelating rounds are undergone, the metals in the body can shift, and the chelation element can begin pulling out other metals, deeper within the body. When I initially started IV chelation, I was excreting a whopping ton of mercury, lead, and cadmium. After many months and many rounds, as those stores began to lessen, the chelation began pulling out more “other” hidden metals, like arsenic, thallium, and even uranium! (I even had a doctor accuse me of lying about my dietary fish intake, since more and more chelation pulled out more and more mercury - alas!)
- DOSING: A low starting dose may be good to evaluate the patient’s response before titrating up, as aggressive initial chelation may unnecessarily increase symptoms and even heighten toxicity.
- METALS REACHED: Chelation tends to first pull metals from the plasma, kidney and liver, followed by the bone and central nervous system.
- NUTRIENTS: Pharmaceutical chelation will inevitably pull out essential minerals to a lesser or greater extent. As such, it is vital that the patient is monitored for his or her nutritional status during the entire chelation process, and that he or she consumes a mineral rich diet, and supplements accordingly. That said, acute mineral supplementation should not occur simultaneously with chelation, since the chelation may simply pull that out in the process.
- PULSING: Due to the aforementioned nutrient situation, it is often recommended that patients “pulse” their chelation in rounds, so as to allow time for the body to remineralize.
- REDISTRIBUTION: When chelating, metals can be pulled from being “safely” locked away in fat stores, soft tissue and bone, to enter the bloodstream. If not eliminated, they may do further damage, and redistribute into other tissues, causing new damage.
- COMBINATION THERAPY: Combining various chelators can provide the potential benefits of a synergistic effect, wider scope of target tissue, increased excretion, and reduced likelihood of redistribution, all with potentially lower doses of the individual chelators to boot. For example, a 1995 study found that combining DMSA and EDTA increased lead excretion and seemingly stopped any redistribution.
- THE KIDNEYS: Pharmaceutical chelation (especially when administered via IV), tends to work primarily via the kidneys. On the one hand, this can be taxing on the kidneys, and chelation has understandably been linked to renal insufficiency. On the other hand, the chelation process may ultimately alleviate the kidney of a large burden, and studies have shown chelation can actually improve kidney function.
- SUCCESS: Despite all the scariness and uncertainty, many studies do show very successful results with pharmaceutical chelation, and ultimate resolution of symptoms.
THE BIG THREE
In this post, I will be focusing on the 3 primary pharmaceutical chelators used in practice today: EDTA, DMSA, and DMPS. These fulfill (to lesser or greater extents), important factors for pharmaceutical chelation: they are water soluble and PH stable (many chelating agents are not stable in super acidic environments, while on the flipside, highly alkaline metals may be less accessible to chelators), they do not transform into other substances before chelating, they are able to cross physiological barriers to actually reach stored metals in the body, they form chelate complexes which are ideally inert or at least substantially less toxic than the original heavy metal, and they support its excretion from the body.
Heavy metal chelation via these pharmaceutical agents first started in WWII, when the organic dithiol compound dimercaprol, also known as British anti-Lewisite or “BAL”, was developed to address arsenic poisoning from the chemical warfare weapon gas known as - you guessed it! - Lewisite. BAL was also found to be effective for mercury. The chelator EDTA (first synthesized in 1935), was later developed for lead poisoning. In the 1960s, BAL was then modified into 2,3-dimercaptosuccinic acid (DMSA), which was quite effective but with less side effects than BAL and EDTA. Finally, DMPS was formulated for chelating mercury in the Society Union in the 1950s.
NOTE: As chelation is used to address a wide array of potential metal body burdens, (with no agent being exclusive to mercury) I will be exploring the role of chelation in heavy metal toxicity for all heavy metals.
CaNa2EDTA (hereafter referred to as EDTA) is most well known for its ability to effectively chelate lead from the body, though it can also chelate cadmium and mercury, among others. Studies indicate it initially chelates a substantial amount of lead, and once that burden is lessened, more easily attaches to mercury and other metals. Its chelation mechanism works in part by displacing calcium. Since EDTA is so lead specific, it may not be the best substance for a provocation test to evaluate the overall body burden of metals.
Most authors attest that EDTA cannot chelate metals from the brain, however recent research indicates it may cross the blood brain barrier, particularly in patients with neuroinflammation. Others have noted increased neurological symptoms with EDTA.
EDTA can be taken orally to address lead and cadmium in particular, but does not boast super amazing absorption rates. It is typically administered via IV or suppository. It also requires dilution, and longer IVs drip times (typically 1-2+ hours). That said, EDTA typically maintains a brief half life of 20 minutes to one hour (though this may reach up to 3 hours), and approximately 95 percent is excreted after 24 hours. So once it’s in, the process is fairly quick!
EDTA does tend to deplete essential minerals, notably zinc and calcium. (Zinc supplementation is recommended afterwards.)
EDTA may redistribute metals, including to the brain.
Potential adverse effects of EDTA include kidney failure, low calcium, arrhythmias, increased bleeding, depression of bone marrow, convulsions, among others.
PROS: Very effective for lead, short half life, can be taken at home as a suppository.
CONS: Pulls out many essential minerals (particularly zinc), has the most potential adverse side effects, may distribute metals to the brain.
PRIMARY CHELATED METALS: Lead, Cadmium, Calcium (hypercalcemia)
PRIMARY CHELATED NUTRIENTS: Zinc, Copper, Calcium, Magnesium
DMSA was developed after EDTA, and was notable for fewer side effects. Out of all the dithiol chelators, it is the most gentle, with a large therapeutic window, and also pulls out the least amount of essential minerals. As such, DMSA may be best for those particularly sensitive, or for children. It can chelate most of the heavy metals, including lead, mercury, and arsenic, though it does have a higher affinity for mercury than lead.
When used at its recommended dosage, DMSA does not tax essential minerals. One study even claims that with DMSA, ‘No significant loss of essential metals like zinc, iron, calcium and magnesium are observed. “ That said, DMSA may have an affinity for copper, and can create copper imbalances and copper metabolism issues, which may encourage problems with redistribution of heavy metals.
Oral DMSA is not very strong, but still maintains decent lead chelation ability. (It can also be administered via IV). When administered orally, only about 20% is absorbed, though it might be most effective for GI toxicity when administered via this route. (Though studies do show reduced body burden with oral supplementation.) DMSA’s half life ranges from 2.5 - 3.5 hours. The half life may be increased if the individual is suffering from an increased body burden.
DMSA is distributed extracellularly. It is unclear if it may redistribute, but in any case,it is much less likely to than EDTA. (DMSA does not seem to enter bile either, which could minimize redistribution.) While most sources maintain that DMSA cannot pull mercury from the brain, one rodent study did find that IV DMSA was the “most efficient chelator for brain mercury. On the flipside, DMSA does not seem to redistribute metals to the brain. But again, who knows, and while one study noted DMSA may redistribute mercury to the brain, this may lessen as the chelation continues. Other studies attest DMSA may lesson metal redistribution after chelating with DMPS or EDTA. And lastly, another study noted that - while DMPS tends to be the go-to for mercury - DMSA may actually be more effective for chelating mercury from the brain. So basically, I JUST DON’T KNOW GUYS.
Potential adverse effects of DMSA include GI or skin issues, mild reductions in white blood cell counts, and elevated liver enzymes.
PROS: The most “gentle” of the big three, can be taken orally or via IV, does not seem to deplete as many vital nutrients, higher affinity for cadmium than DMPS, oral DMSA can be effective for lead
CONS: Not as potent, especially compared to EDTA for lead, or DMPS for mercury, may be limited to extracellular distribution
PRIMARY CHELATED METALS: Broadspectrum (cadmium, lead, mercury, arsenic etc.)
PRIMARY CHELATED NUTRIENTS: Copper
DMPS is arguably the chelator of choice for mercury specifically, though it also chelates lead, arsenic, and cadmium, among others. It may be one of the best choices for provocation challenge tests to evaluate overall heavy metal burden, since it does a decent job of pulling out a broad spectrum of heavy metals (again, with a particular affinity for mercury).
Despite boasting a potentially 39% higher oral absorption than DMSA, DMPS is typically administered via IV. It has a half life of around 1-3 hours, but closer to 10 hours when administered orally (which is less effective). It can also be administered as direct pushes into the vein - a route I personally chose to go. When intravenous, the chelated metals are rapidly excreted via the kidneys through the urime - around half within an hour, and around 90% in 24 hours. The half life may be increased if the individual is suffering from an increased body burden.
DMPS may lead to redistribution of metals, but likely does not redistribute metals to the brain, and some studies indicate DMPS may actually alleviate mercury from the brain. Interestingly, studies have shown that DMPS may not even redistribute to rat brains, compared to DMSA which may redistribute to rat brains but not human brains. One study even mandates that “no major [emphasis mine] adverse effects following DMPS administration in humans or animals have been reported.” Another noted that “adverse effects of DMPS may be due to the increased presence of circulating heavy metal or related toxins.”
Potential adverse effects of DMPS include GI or skin issues, and elevated liver enzymes. Patients also may become sensitive to the compound. (While this can happen with any compound, it seems to be more of a “thing” with DMPS.)
PROS: Very effective for mercury, as well as lead and other metals, likely does not redistribute to the brain, may chelate intracellularly unlike other more limited chelators
CONS: Typically only administered via IV, not quite as gentle as DMSA
PRIMARY CHELATED METALS: Mercury, Lead, and others
PRIMARY CHELATED NUTRIENTS: Broad spectrum, but not as depleting as EDTA.
Alpha Lipoic Acid (The Cutler Protocol)
Andrew Cutler’s ALA protocol is an intense, specific protocol which utilizes the antioxidant Alpha Lipoic Acid to chelate mercury, with specific attention to ALA’s half-life of 3 hours. As ALA is both fat and water-soluble, it may be an effective method for chelating mercury from the brain. That said, redistribution of mercury (including to the brain) is a major concern.
Alpha lipoic acid began its therapeutic use in 1960s Germany, originally for liver cirrhosis and diabetic polyneuropathy, and later for heavy metal toxicity. ALA is able to enter cells and form complexes with mercury, to increase its excretion. ALA is produced naturally in the body, but it can also exist in free form when taken as a supplement. In the later form, it can bind to mercury, penetrating cells and reaching high levels within 30 seconds of ingestion. In comparison to other chelation agents, one study found DMPS removed 86% of mercury in 3 hours, DMSA removed 65%, glutathione removed 50%, EDTA removed 20%, and ALA removed 35%.
ALA can function as both an antioxidant and a chelator, and also may increase levels of glutathione and cysteine - both important factors in chelation. Animal trials often find decreased oxidative stress and significant reductions in mercury with ALA supplementation. One even found that ALA restored glutathione levels - which had been decreased by 63% due to heavy metal toxicity - completely in the rat brain.
Studies on humans have found high doses (600 mg three times daily) do not result in toxicity. Interestingly, some studies have found that lower doses of ALA may be more effective than higher doses at increasing mercury elimination (which would support the Cutler protocol concept). On the flipside, other studies have found that higher ALA ratios were necessary to prevent toxicity, while lower dosing increased toxicity. So who knows!
Studies have notably found that ALA may redistribute mercury - pulling it from one source and “dropping” it in unburdened tissues, causing further damage. For example, one study found that, while ALA supplementation decreased mercury in the kidney, it increased mercury levels in the brain, lung, heart, and liver. Other studies have found increased mercury levels in the muscle, brain, and intestines of rats supplemented with ALA. The trend seems to be that ALA can pull from high mercury-concentrated tissues and reduce those levels, but add it to other tissues with originally lower levels.
Andrew Cutler’s ALA protocol serves to address this redistribution issue by acting on ALA’s half life of 3 hours. The idea goes that supplementing ALA every 3 hours keeps it constantly present in the bloodstream, “picking up” any mercury that is “dropped off.” This dosing is usually constructed in rounds, typically of 3-4 days. If you choose to self-treat mercury toxicity with Cutler’s protocol, I encourage you to extensively research it.
Our bodies naturally chelate metals, while various “natural” compounds derived from plants, microorganisms, and other sources, can help chelate and address a person’s metal burden.
The Mercury/Thiol Connection
Mercury is highly reactive with substances containing thiols (such as glutathione, cysteine or albumin), and their interaction involves the processing, transformation, storage, and excretion of mercury within the body. Mercury will readily and instantly bind with these free thiol substances, forming more stable substances. As such, higher levels of free thiols may protect against mercury accumulation, since the mercury binds to them, and not other tissues.
Our body naturally instigates a chelation process via agents called metallothioneins (MTs). These proteins are rich in the thiol amino acid cysteine, which is the most reactive amino acid with mercury. MTs can bind, transport, store, and detox metals in the body via thiol groups. Unfortunately, when mercury binds to metallothioneins in place of trace metals like copper and zinc, it can reduce the MTs’ effectiveness.
In fact, the isolated compound cysteine is a primary chelation agent for treating heavy metals in the food supply, with studies showing treating products (such as fish) with cysteine solutions successfully reduces levels. For example, researchers in 2012 effectively removed 90% of the mercury in fish utilizing a cysteine solution, with other studies finding more moderate reductions of around 40-50%. While you may not be keen on dousing your food in cysteine, some therapies use the more accessible hydrolyzed whey protein (rich in cysteine) as a supplement to address metal levels in the body. Cysteine is also important for excreting heavy metals via the feces, as well as protecting the liver. Cysteine can be taken as a supplement in its precursor form of N-acetylcysteine (NAC), to supplement chelation therapy. Please work with a practitioner for proper dosage and treatment.
Glutathione - which is thiol based - is the body’s major intracellular antioxidant. It also serves to chelate metals, neutralize reactive oxygen species, and mitigate cell damage. Unfortunately, heavy metals - especially mercury - can intensely deplete glutathione levels and impair its function. In addition to binding to and using up glutathione stores, mercury can also generate free radicals which themselves further drain glutathione levels.
Glutathione has three main roles in mitigating and protecting from mercury toxicity. For starters, it binds to mercury to create stable complexes which cannot then injure other tissues. This also helps keep mercury from entering cells and becoming toxic within them. Glutathione also acts as a carrier for mercury, encouraging its elimination in the bile and urine. Lastly, glutathione upregulates the body’s antioxidant potential, serving as a defense against oxidative stress from mercury.
Supporting glutathione synthesis in the body is therefore key. Glutathione is not easily absorbed as a supplement, so supplemental glutathione is best achieved via IV, or liposomal glutathione. And since glutathione is essentially the body’s master antioxidant, while undergoing any chelation therapy, it can be fortuitous to support the body’s natural antioxidant system, via the potential use of vitamins and amino acid supplementation, such as vitamin C, E, tauraine, the aforementioned NAC, etc.
FOODS AND FOOD-DERIVED COMPOUNDS
Some foods are known to bind to mercury, and increase its excretion. That said, the topic is hotly debated, since some of their effectiveness hasn’t been extensively studied, while others insist their finicky bonds mean they may bind to mercury, but drop it somewhere else in the body, causing more harm from the mercury in new undamaged tissue. Yikes!
My personal thoughts on the matter is it’s likely individual. If you excrete mercury easily, and aren’t taking in too much, I imagine these substances may encourage more excretion than redistribution. That said, if you’re mercury toxic (which may indicate you have issues dealing with mercury), some of these various compounds may just make things worse. I personally got massive brain fog and fatigue when I high dosed chlorella, but that’s just me!
A variety of compounds found in fruits and vegetables may assist mercury removal:
Fiber in the form of things like cellulose, lignans, and pectins in fruit and vegetables may reduce heavy metal absorption by binding to heavy metals. It also may modulate gut flora to encourage their metabolization of heavy metals. That said, the type of fiber may be important, as one study found fiber from fruit reduced mercury, while fiber from flaxseed actually increased mercury absorption.
Polyphenolic compounds in fruit and vegetables can serve as ion chelators and support metal chelation, thanks to their hydroxyl groups. Flavonoids and catechins found in plants may also scavenge and chelate metals in the body. Quercetin (abundant in onions, grapes, and berries) is a particular flavonoid with very potent free radical scavenging ability, as is rutin (rich in things like apple and teas). Polyphenols can also serve as potent antioxidants, supporting the cellular stress response to heavy metals, as well as the body’s innate chelation system.
While phytates are often scorned in the Paleo-sphere for their nutrient binding ability, this may come in handy when it comes to heavy metals! Phytates may bind to metals, and form complexes in a range of PHs, making the metals less soluble and bioaccessible.
The polyphenolic compound known as tannins - made famous by wine! - are notably good cheltors for heavy metals. I’ll raise a glass to that!
The body’s internal PH can affect the levels of mercury, and various acids have been shown to chelate mercury to lesser or greater extent. EDTA (ethylenediaminetetraacetic acid) itself is an acid, while other acids with mercury-chelation potential include acetic acid, citric acid, lactic acid, and ascorbic acid. Some studies have used especially strong acid solutions to change pH and address heavy metals. The optimal pH for removing mercury may be anywhere from 1- to around 4.25. Researchers Hajeb and Jinap in 2009 even concluded pH to be the most dominant factor in reducing mercury.
Activated carbon charcoal can serve as a fantastic binder, not only for metals, but any toxins in general. As it does bind to nutrients in the GI tract, it is best taken in the fasted state.
Say what? While this may seem hard to believe, alcohol has actually been shown to encourage mercury excretion via the breath! Historically, sick workers in the Spanish colonies were often sent to hot climates, with a treatment of beer drinking and sweating to exhale the toxic “vapors.” This would often reduce mercury toxicity symptoms, including salvation, ulcers, and tremors.
Since then, studies have revealed that alcohol does, indeed, upregulate mercury excretion via the breath. One study in 10 individuals found an approximate fivefold increase in mercury excretion via the breath half an hour after alcohol intake, regardless of the participants' initial mercury levels, with higher levels of alcohol generating higher mercury levels. And even minute doses of a mere 0.1 g ethanol/kg body weight (or about 0.08 L wine) lead to increased mercury excretion. Plus, if you get your alcohol from red wine - which is rich in tannins discussed above - we just may be in business!
Alginates from seaweed are known for their ability to absorb heavy metals in a biomass, assisting in their removal. While studies have shown they seaweed can inhibit the absorption of heavy metals, alginates tend to supersede that. Their low molecular weight allows them to selectively bind to heavy metals but not nutrients, and minimize reabsorption of heavy metals.
Chlorella is a type of algae rich in chlorophyll, often promoted for its ability to chelate mercury and other heavy metals. Indeed, many rodent studies have shown increased excretion of mercury with chlorella supplementation. A human trial of 90 days of chlorella supplementation (in the form of chlorella vulgaris) in patients with dental amalgams, found the chlorella did indeed reduce mercury levels. That said, some propose that chlorella may be finicky, and redistribute heavy metals, or even possibly be contaminated with heavy metals itself. I think chlorella works fantastically for some people, but makes others worse. (I tend to be the latter).
Cilantro has been promoted as a heavy metal chelator, though I believe it may more likely grab and redistribute mercury, without necessarily assuring its complete excretion out of the system. I can’t find any extensive studies on cilantro, though one trial did find it equal to placebo. In other words, I personally wouldn't turn to cilantro for heavy metal detox.
Coffee And Tea
Interestingly, some studies have found adding black coffee and black or green tea to boiled fish could reduce mercury levels by around half! This may be due to the drinks’ plant compounds, such as flavonoids and catechins.
While I couldn’t find an overwhelming number of studies on the subject, egg whites may form a protective barrier in the stomach and interact with mercury salts to delay or hinder their absorption, while also protecting the stomach barrier. Egg whites are also rich in the previously discussed amino acid cysteine.
You guys know I love my fruit, so I was happy to read a 2003 study which found that "Simple and multiple regression analyses showed that the strong relationship between fish consumption and Hg exposure was significantly modified by fruit consumption: for the same number of fish meals, those who ate more tropical fruits had lower hair mercury levels." Bring on the pineapple!!
Modifed Citrus Pectin
Pectin - a gelatinous complex polysaccharide and soluble fiber found in fruits - has been shown in general to have heavy metal binding abilities. Modified citrus pectin (MCP), however, goes much beyond that! While typical pectin tends to be non-digestible, modified citrus pectin is formed from the peel of citrus fruit, and is broken down so that it can actually be absorbed into the bloodstream and treat mercury toxicity systemically. It can bind to mercury without redistributing it, and without binding to vital nutrients.
Studies have shown consistent, prolonged use of modified citrus pectin can substantially reduce mercury levels in the body. Five case studies in 2007 found a 74% average decrease in heavy metals levels (including mercury) when modified citrus pectin (around 4 grams a day) was used alone or in combination with some complementary alginates for 3 months. This was with no side effects, and increased health to boot! Notably, when one patient discontinued modified citrus pectin but continued exposure to mercury via fish consumption, his total mercury levels began to rise, indicating modified citrus pectin may play a key role in mitigating daily mercury exposure! The researchers noted higher doses could be used as well with no side effects, while a maintenance dose would be around 2-4 capsules per day.
While, granted, omega-3s are often rich in mercury-laden fish, EPA and/or DHA may augment mercury toxicity. They may do this in part by reducing actual mercury assimilation and/or decreasing cell death due to mercury exposure.
A variety of studies have been conducted on probiotics, finding some may offer protective effects against heavy metal toxicity, though the extent and effectiveness seems to be highly strain specific, with further study needed. For example, a 2014 randomized pilot study of Tanzanian pregnant women found yogurt fortified with the probiotic strain L. rhamnosus GR-1 prevented increased mercury levels compared to a control group, insinuating the probiotic’s protective effect.
Similarly, studies on germ free-mice have revealed that the gut microbiome may protect against heavy metal toxicity. A 1977 study found that while control mice excreted around half of an infused mercury burden within 10 days, germ-free mice only excreted around ¼. The germ-free mice also retained more mercury in their organs.
Other species of lactic acid bacteria have shown the ability to bind to heavy metals in vitro, including L. plantarum and Bifidobacterium.
While the mechanism of action is uncertain (and may vary), it’s postulated to include passive sequestration, enzymatic detoxification (which serves to demethylate mercury), as well as the prevention of mercury absorption in the GI tract.
SALTWhile I’m not advocating salt as a go-to mercury detox method, some studies have found that using salt solutions to treat fish could assist mercury removal.
Vitamins C and E
Vitamins C and E are potent antioxidants which can scavenge free radicals, support the body’s antioxidant system, and protect cells. These antioxidant vitamins can easily be depleted by mercury toxicity, so keeping a steady supply of them coming is key!
Zinc supplementation has been shown to play a key role in protecting against mercury toxicity and reducing heavy metal burden. Studies in rodents administered with mercury have shown zinc pretreatment could prevent weight increases in the kidney caused by the mercury. Zinc pretreatment also partially mitigated lost body weight from mercury toxicity, decreased kidney thiol levels, and increased creatine levels.
Selenium may be significant for heavy metal chelation by binding to mercury and rendering it inert, as well as combating reactive oxygen species generated by mercury toxicity. That said, please see the selenium section for the complex details on this.
Because metals have an affinity for sulfur containing peptides, sulfur-rich foods (such as garlic, cruciferous veggies, and eggs) may support heavy metal chelation, as well as a person’s antioxidant system. That said, if a person is sulfur sensitive, sulfur-rich foods may yield negative effects.
Zeolites are microporous minerals which can have the ability to trap heavy metals in their cage-like structure. While I couldn’t find extensive research on them, I do particularly love Results RNA ACZ Nano Advanced Cellular Zeolite Extra Strength
OTHER DETOX METHODS
In addition to diet and chelation agents, there are other detox methods you can utilize to support mercury detox!
Saunas have long been used for detoxification. We naturally release sweat through toxins, so sweating in a sauna can naturally support detox. That said, a low-EMF infrared sauna (such as Sunlighten) can produce an even more “productive" sweat by heating the body at the cellular level, while supporting metabolism. Although you may not feel as hot or even sweat as much in an infrared sauna, you’ll like get more bang for your buck! Some protocols suggest pairing sauna use with supplements like niacin, to increase mercury excretion.
Ionic Foot Baths
While people often raise an eyebrow at ionic foot baths, they have an immense array of testimonials, and I personally experience great benefit from them. Dr Dietrich Klinghardt - one of the go-to experts on mercury toxicity - advocates them as a go-to method. An important note is that the gunk that shows up in the water is likely not 100% toxins, but perhaps more like 20%. That said, the ionization process supports the body’s natural detoxification system, and is estimated to increase toxin excretion throughout the urine for the next 24 hours. Heavy metals are said to show up as black colors and black flakes. When I personally started using one, the water consistnetly turned dark black, with dark flakes! However, what really sold me, is my sister used my unit the other day - and not a single black spot showed up. I was sold. I wholeheartedly recommend ION BALANCE Ionic Detox Foot and Cell Spa.
I hope, dear friend, if you have experienced any of the (literal) madness of mercury toxicity, that you may find some peace in this epic blog post, and that - regardless of your mercury exposure - you may learn from my personal trials and tribulations! While we are not to blame for our mercury toxicity, we can take responsibility in minimizing our exposure, and assisting our body in getting out what’s in!
As for the route I personally chose, I primarily utilized DMPS, with many pushes at lower dosages. While I initially felt sick in the process, as I progressed, I felt increasingly better, and eventually started feeling amazing from DMPS. I’ve seen very significant reductions in mercury levels. I’ve discontinued for a few months to remineralize and recover, but I plan to pick it back up soon! (I want those metals out!!) Weighing the cost benefits - especially how shockingly high my levels were and how I’m “still young” - I personally decided fast and strong was the way to go for me. Of course that is me, and you’ve got to do you. In any case, I recommend working with a qualified practitioner (hopefully one who believes in you, and who will not make you feel emotionally worse for the wear). I’ve also found the Results RNA ACZ Nano Advanced Cellular Zeolite Extra Strength to be highly effective.
In any case, if you feel like you are poisoned or going mad, and fear that it’s all in your head, I want you to know you are not crazy, and while 10% of your mercury burden may in fact be in your brain, it’s not all in your head! I pray you may find peace and strength, and hold on to your sense of self through it all. May the coming days bring sunny skies, and dark nights featuring other celestial planets beyond the one so harrowingly named here. You got this!
Effect of Marine Omega 3 Fatty Acids on Methylmercury-Induced Toxicity in Fish and Mammalian Cells In Vitro
Current approaches of the management of mercury poisoning: need of the hour
The Long-Term Algae Extract (Chlorella and Fucus sp) and Aminosulphurate Supplementation Modulate SOD-1 Activity and Decrease Heavy Metals (Hg++, Sn) Levels in Patients with Long-Term Dental Titanium Implants and Amalgam Fillings Restorations
In Vitro Antioxidant versus Metal Ion Chelating Properties of Flavonoids: A Structure-Activity Investigation
The inhibition of mercury absorption by dietary ethanol in humans: cross-sectional and case-control studies
Arsenic, Cadmium, Lead, and Mercury in Sweat: A Systematic Review
Integrative medicine and the role of modified citrus pectin/alginates in heavy metal chelation and detoxification--five case reports
Combining strains of lactic acid bacteria may reduce their toxin and heavy metal removal efficiency from aqueous solution
Randomized open-label pilot study of the influence of probiotics and the gut microbiome on toxic metal levels in Tanzanian pregnant women and school children
Toxic effects of mercury on the cardiovascular and central nervous systems
Rethinking mercury: the role of selenium in the pathophysiology of mercury toxicity.
Cooking can decrease mercury contamination of a mushroom meal: Cantharellus cibarius and Amanita fulva
Cooking process evaluation on mercury content in fish
Effects of Various Cooking Processes on the Concentrations of Arsenic, Cadmium, Mercury, and Lead in Foods
A Quantitative Synthesis of Mercury in Commercial Seafood and Implications for Exposure in the United States
Neurotoxic risk caused by stable and variable exposure to methylmercury from seafood
EPA and FDA Advice For: Women who might become pregnant, women who are pregnant, nursing mothers, young children. What you need to know about mercury in fish and shellfish: Food and Drug Administration
EWG Study: Smarter Seafood Choices Can Lower Mercury Exposure For Parents And Their Future Children
The human brain is a fascinating organ that helps define our personalities, our health, communication and social interactions, as well as keeping us alive by directing all of our bio-activities
Seafood Consumption and Components for Health
Nutrient and Methyl Mercury Exposure from Consuming Fish
Mercury Concentrations in Fish - FDA Monitoring Program (1990 - 2010)
Trophic transfer of metals along freshwater food webs: Evidence of cadmium biomagnification in nature
Seafood consumption and blood mercury concentrations in adults aged ≥20 y, 2007–2010
A Review of Mercury Bioavailability in Humans and Fish
Mercury alert: Is canned tuna safe?
Chelation in Metal Intoxication
Comparison of chelating agents DMPS, DMSA and EDTA for the diagnosis and treatment of chronic metal
Sodium 2,3-dimercapto-1-propanesulfonate (DMPS) treatment does not redistribute lead or mercury to the brain of rats. Toxicology.
MERCURY ELIMINATION WITH ORAL DMPS, DMSA, VITAMIN C, AND GLUTATHIONE: AN OBSERVATIONAL CLINICAL REVIEW
Clearance half life of mercury in urine after the cessation of long term occupational exposure: influence of a chelating agent (DMPS) on excretion of mercury in urine.
Clearance half life of mercury in urine after the cessation of long term occupational exposure: influence of a chelating agent (DMPS) on excretion of mercury in urine
Rationale for the Successful Management of EDTA Chelation Therapy in Human Burden by Toxic Metals
Accumulation and removal of Hg203 in different regions of the rat brain
DMSA is an orally active chelating agent that is much less toxic than BAL and its therapeutic index is approximately 30-times higher
EGGS AND MILK AS ANTIDOTES AGAINST MERCURIC CHLORIDE
Method for withdrawing heavy metals and heavy metal salts from raw fish material. Russia Patent 2166860. Ascorbic
Effects of processing on the proximate and metal contents in three fish species from Nigerian coastal waters
The effects of different methods of cooking on proximate, mineral and heavy metal composition of fish and shrimps consumed in the Arabian Gulf
Chemical contaminants in aquafeeds and Atlantic salmon (Salmo salar) following the use of traditional- versus alternative feed ingredients
Quantitative Analysis of the Benefits and Risks of Consuming Farmed and Wild Salmon
Combined therapeutic potential of meso 2,3-dimercaptosuccinic acid and calcium disodium edetate in the mobilization and distribution of lead in experimental lead intoxication in rats
Dietary Strategies for the Treatment of Cadmium and Lead Toxicity
Tannins, the polyphenolic compounds in plants, are also good chelators for metal ions
Reduced mercury excretion with feces in germfree mice after oral administration of methyl mercury chloride.
Oral Administration of Probiotics Inhibits Absorption of the Heavy Metal Cadmium by Protecting the Intestinal Barrier
The effect of modified citrus pectin on urinary excretion of toxic elements
Eating tropical fruit reduces mercury exposure from fish consumption in the Brazilian Amazon