Is Mercury Making You Sick?
Julian Whitaker, MD
Alice in Wonderland’s Mad Hatter was not just a figment of Lewis Carroll’s imagination. Unfortunately, he represented an all-too-real 19th-century figure: the brain-addled hat maker, whose tremors, slurred speech, and manic-depressive behavior resulted from spending long hours working with felt in mercury-infused water.
You may not run into many mad hatters these days, but mercury toxicity remains a significant threat to our health.
Mercury’s Effects Are Pervasive
Mercury has many adverse effects in the body. It easily crosses the blood-brain barrier and attacks the brain and nervous system. It damages the kidneys, lowers hormone levels, and disrupts neurotransmitter activity. It also destroys oxygen-carrying red blood cells and reduces the number and activity of immune cells that protect against cancer, viruses, and other pathogens. In addition, mercury increases the production of free radicals and depletes the body of important antioxidants that keep free radicals in check.
Mercury is especially damaging to the fetus. Children of women exposed to mercury during pregnancy may exhibit a variety of abnormalities, including delays in walking and talking and neurological impairment. According to a National Academy of Sciences report, up to 60,000 children may be born in the US each year with mental impairment due to exposure to mercury in the womb. Mercury is also transmitted during breastfeeding, placing infants at risk during a time when their nervous systems are still developing.
Adults Are Vulnerable, Too
Mercury poisoning can also affect adults, though the symptoms may be more subtle than the neurological problems seen in young children. The more obvious symptoms include numbness and tingling in the extremities, loss of coordination, and tremors. But mercury poisoning can also cause fatigue, muscle weakness, dizziness, and headaches as well as mental problems such as memory loss, depression, irritability, and difficulty concentrating.
Unfortunately, because the effects of chronic low-level exposure to mercury can take years to appear, they are easily dismissed as “normal” consequences of aging or attributed to other causes. Only after successful treatment to eradicate mercury from the body can the devastating effects of this poison be fully appreciated.
Dental Fillings Release Mercury
So-called “silver” amalgams used in fillings are actually 50 percent mercury, with smaller amounts of other metals. By 1845, dentists were well aware that mercury was toxic and could cause neurological problems. In fact, that year the American Society of Dental Surgeons (the predecessor to the American Dental Association) adopted a resolution for its members not to use mercury amalgam, and members who violated this resolution were often suspended.
Today the American Dental Association is the greatest proponent of mercury amalgam. Until recently, the ADA claimed that mercury was completely safe, as it was “sealed” inside the amalgam. But we now know that this isn’t true. Mercury vapor is released whenever you chew, brush or grind your teeth, or drink hot beverages. Each amalgam releases approximately 10 micrograms of mercury vapor every day, and at least 1 microgram is absorbed by your body. One microgram might not sound like very much, but it takes about 70 days for the body to eliminate a single microgram, during which another 70 micrograms of mercury have accumulated.
Fish Are Another Source of Mercury
Although the Environmental Protection Agency has nothing to say about the dangers that mercury fillings present to patients (that is the territory of the FDA), it does classify scrap mercury amalgam as hazardous waste and has strict regulations regarding its disposal.
The EPA is equally serious about another common source of mercury: contaminated fish. Due to the natural release of mercury from the earth’s crust as well as human activities like the burning of fossil fuels, our nation’s waters are polluted by this toxic heavy metal. Fish absorb mercury when they feed on smaller aquatic organisms, and we absorb mercury when we eat fish.
This doesn’t mean you should give up eating fish altogether. I heartily endorse fish as a dietary staple. Most of the fish you’re likely to eat regularly have extremely low levels of mercury and are considered safe. These include shrimp, pollock, salmon, cod, catfish, clams, flatfish, crabs, and scallops.
However, large predatory fish, which feed on smaller fish and have much longer life spans, can accumulate mercury at amounts that exceed the safety threshold. Shark, swordfish, king mackerel, tilefish, and very large tuna (sold as steaks or sushi) are the worst offenders, and I don’t recommend that anyone eat these larger types of fish more than once a month. Because mercury levels in canned tuna can vary from low to moderately high, I recommend limiting your intake to one can per week.
It’s also a good idea to minimize your intake of freshwater predatory fish like pike and walleye. Depending on levels of mercury in the local waters, these fish can also exceed the safety limit.
Effective Therapies Exist
At the Whitaker Wellness Institute, we may test for mercury toxicity in patients who suffer from depression, anxiety, memory loss, chronic fatigue, cancer, or an autoimmune disease such as multiple sclerosis. If levels are elevated, we recommend a course of DMSA chelation, administered in pill form. (Mercury does not respond well to IV EDTA chelation.) This regimen may be repeated until mercury levels recede into the normal range. Therapeutic doses of DMSA are available only with a prescription.
In some cases, we recommend that patients also have their mercury amalgams replaced with biocompatible materials. This requires finding a dentist who is specially trained in the removal of amalgams and has procedures in place to minimize exposure to mercury vapor during the removal procedure. (I have undergone this lengthy and expensive process myself.)
- For information on receiving mercury chelation at the Whitaker Wellness Institute, call (800) 488-1500 or click here.
- Echeverria D et al. Neurobehavioral effects from exposure to dental amalgam Hg(o). FASEB J. 1998 Aug;12(11):971-80.
- Grandjean P et al. Cognitive performance of children prenatally exposed to “safe” levels of methylmercury. Environ Res. 1998 May;77(2):165-72.
- Huggins HA et al. Uninformed Consent. Charlottesville, VA: Hampton Roads, 1999.
- Pregnant women in US advised not to eat certain types of seafood. Reuters Health, Jan 15, 2001.
Modified from Health & Healing with permission from Healthy Directions, LLC. Copyright 2007. Photocopying, reproduction, or quotation strictly prohibited without written permission from the publisher. To subscribe to Health & Healing, click here.