Key takeaways:
~ Mercury exposure has long been known to cause neurological problems.
~ Organic mercury is more likely to cause health issues than inorganic mercury.
~ Genetic variants play a role in how quickly you excrete mercury; diet and lifestyle factors are also important.
~ Research studies show that certain natural supplements may help with detoxification.
Members will see their genotype report below, plus additional solutions in the Lifehacks section. Join today.
Mercury: Effects and Detoxification
Mercury is the only metal that is a liquid at normal temperatures and pressures. It is classified as a heavy metal (along with lead, cadmium, iron, zinc, etc.), and it can be toxic in the body even at very low levels.
Mercury can build up in the body, causing negative health effects on the central nervous system and the kidneys. It is a fancy way of saying that it hurts the brain, causing fatigue, memory impairments, nervousness, insomnia, and tremor. Exposure to a lot of mercury at once can cause nausea, vomiting, kidney damage, bloody diarrhea, and even death.[ref]
Exposure routes: how does mercury get in the body
We are exposed to mercury through a variety of pathways:
- Fish and seafood contaminated with mercury are the most significant sources of mercury for many people.
- Dental amalgam (silver fillings) can break down and possibly cause mercury to enter your system.
- Certain vaccines contain trace amounts of mercury (thimerosal) as a preservative.
- Occupational exposure can happen either through breathing in mercury-contaminated air or via skin exposure. Industries that use mercury include chemical labs, gold mining, battery makers, dentists and amalgam makers, insecticide manufacturing, and CFL bulb manufacturing.
Air pollution containing mercury can also be a problem in some areas. Elemental mercury can be a contaminant in air pollution, and it also can be inhaled when near liquid mercury. Liquid mercury (such as in CFL bulbs or thermometers) easily vaporizes and is absorbed in the lungs. Mercury can also be absorbed through the skin.
Forms of mercury:
All forms of mercury can be a problem, depending on the concentration. When it comes to detoxifying mercury, though, the different forms of mercury use different detox pathways.
Mercury can be classified as:
- Organic mercury: mainly methylmercury, which is the form found in seafood
- Inorganic mercury: elemental mercury in air pollution (fossil fuel emissions), evaporation from liquid mercury, mercuric salts dissolved in water
Organic mercury is formed from inorganic, airborne mercury, such as from fossil fuel emissions entering bodies of water. In aquatic sediments, certain bacteria convert mercury into methylmercury. Extremely toxic, methylmercury can be easily absorbed via drinking water or eating fish that have absorbed the methylmercury.
Dental amalgams – silver fillings – are another source of exposure to inorganic mercury. To add to the complexity, some forms of mercury convert in vivo from inorganic to organic.
Why is mercury toxic?
While mercury toxicity can affect someone at any age, it is especially devastating to a developing fetus. Exposure to low levels of mercury can affect brain formation by killing off the neuronal stem cells that form the brain.
Mercury also affects children and adult brains, just not at the devastating level seen in developing babies. Neurogenesis, or the formation of new neurons, happens at low levels throughout life. Research shows that mercury inhibits the development of astrocytes from neuronal progenitor cells. Instead, there is a shift in cell type from astrocyte formation to more glial cells. While both cell types are important, we need them in the right amount. Essentially, methylmercury is thought to disrupt some of the cell signaling taking place when neurons are forming.[ref]
The term “Mad as a hatter” referred to the neurological changes from long-term mercury exposure. In England, the process of making felt hats used to include using mercury to stabilize the wool. Hat makers often ended up with mercury poisoning symptoms that caused memory loss and personality changes.
Mercury is stored in the brain at a higher level than the rest of the body. Some studies show that the brain stores mercury at 3 to 6 times the rate of the rest of the body.[ref]
Recent research points to a potentially significant way that mercury causes toxicity. Studies now show that mercury can take the place of selenium in specific proteins, causing those proteins not to function. The selenoproteins that are targeted include thioredoxin reductase 1 and 2. These are major antioxidant and redox-regulating enzymes.[ref]
How long does mercury stay in the body?
When inhaled, organic mercury has a half-life of around 60 days in the body. But mercury in the brain can stay there for 20 years or more.[ref]
It takes time for the symptoms of mercury toxicity to show up. Research shows that it can take up to 5 months for some symptoms to appear.[ref]
How is mercury detoxified and excreted?
Mercury is eliminated primarily by glutathione detoxification. It is excreted in bile, feces, or urine. The glutathione-S-transferase enzymes are essential in making mercury soluble in a form that can be excreted from the body.[ref]
Glutathione is synthesized from l-glutamate and cysteine, with glycine also needed for the second step of biosynthesis. All animal cells can synthesize glutathione, and it is an essential antioxidant and detoxification compound.
With the help of enzymes to catalyze the reaction, glutathione is bound to methylmercury (the kind found in fish) for excretion. There are a couple of other routes of detoxification of mercury also. For elemental mercury, free cysteine is also utilized for detoxification. Metallothioneins are cysteine-rich proteins that can bind with mercury for excretion in certain circumstances.[ref]
We want mercury to be excreted as quickly as possible so that it doesn’t hang around and end up in the brain. This detoxification pathway brings us to the genetic variants that impact how well your body excretes mercury.
Mercury Detoxification Genotype Report:
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Lifehacks:
Obviously, you want to avoid exposure to mercury at higher levels. The fact that it can remain in the brain for 20 years is disconcerting.
Which types of fish are highest in mercury?
According to the FDA, fish high in mercury include (listed higher to lower):[ref]
- tilefish
- swordfish
- shark
- king mackerel
- tuna
- orange roughy
- marlin
- grouper
- Chilean bass
- tuna (canned, Albacore)
- white croaker
- halibut
Drink tea with your fish? A recent study showed that tannic acid and EGCG, found in black or green tea, help to block mercury absorption from foods.[ref]
Testing for mercury:
Blood tests and hair metal tests are available to check for mercury. Mercury accumulates in the hair at about 250x the amount seen in the blood, on average. Hair testing accuracy depends on age, gender, and genetics. Normal levels of mercury in the hair are 1-2 ug/g. In hair testing for adults, neurological effects are seen at 50 ug/g. In blood mercury tests, people who don’t eat fish usually have levels below 2ug/L, while individuals who consume a lot of contaminated fish may range from 5 to 10ug/L.[ref]
Supplements that may help with mercury detoxification:
Member Content:
Why join Genetic Lifehacks?
~ Membership supports Genetic Lifehack's goal of explaining the latest health and genetics research.
~ It gives you access to the full article, including the Genotype and Lifehacks sections.
~ You'll see your genetic data in the articles and reports.
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