Mercury from fish, primarily methylmercury, stays in the body for a long time, with a half-life of about 42-57 days in the blood but can accumulate in organs like the brain for months or years, potentially taking up to a year for levels to significantly drop after you stop eating high-mercury fish. While the body excretes some over time, mercury easily crosses the blood-brain barrier and accumulates, especially harmful to developing brains.
The body naturally eliminates small amounts of mercury over time. If you suspect mercury toxicity, consult a healthcare provider for evaluation and testing. Avoid unproven detox methods, as they may be unsafe. Maintaining a balanced diet and following fish consumption guidelines helps minimize mercury risks.
Living in coastal Florida, many of our patients have mercury exposure from seafood consumption. Mercury elimination follows a biphasic pattern: Blood mercury levels decrease by 50% within 2-3 months. Complete tissue elimination requires 6-18 months.
Symptoms of poisoning from elemental mercury
Once in your body, metallic mercury can stay for weeks or months. When metallic mercury enters the brain, it is readily converted to an inorganic form and is “trapped” in the brain for a long time. Metallic mercury in the blood of a pregnant woman can enter her developing child.
But, there are healthy limits to eating fish since they may contain small amounts of mercury. These recommended limits vary by each person, such as children, pregnant women and healthy adults. It can take quite a while, from months to years, for the human body to process and clear mercury completely.
Possible symptoms of methylmercury poisoning may include:
For most people, eating a small amount of fish high in mercury isn't a health concern. Fish are part of a healthy diet. But in a fetus or child, too much mercury can harm the brain and nerves.
The unhealthiest fish to eat are typically large, predatory species high in mercury like shark, swordfish, king mackerel, and imported tilefish, plus bluefin tuna, which are dangerous for brain/nerve health, especially for pregnant women and children; also, farmed salmon and some imported tilapia/catfish raise concerns for contaminants and antibiotics, while orange roughy and Atlantic cod are often cited for high mercury and overfishing/sustainability issues.
Certain nutrients such as Selenium, Vitamin C and E, and Glutathione help with mercury removal. Adding these nutrients in your diet can go a long way in preventing mercury toxicity. Besides, high doses of chlorella, a green algae, has also been proven helpful in reducing body mercury levels.
Studies have shown that dietary vitamin C can reduce the mercury toxicity in terms of reducing mercury concentrations in blood and tissues especially liver and kidney tissues through the urinary excretion as well as enhance the immune responses in organisms (Hounkpatin et al., 2012; Lee et al., 2016).
Subsequently, mercury ions accumulates in the brain and kidney and causes multiple organ damage in the renal, nervous, cardiovascular, and musculoskeletal systems. 6, 7, 8 Because of the strong affinity of mercury for the kidney tissue, the kidney is one of the most susceptible organs to mercury poisoning.
There are numerous possible symptoms of mercury poisoning. Examples include nervousness, numbness, muscle weakness, nausea, and more. Treatment can include avoiding mercury and, in severe cases, chelation therapy. Mercury is a heavy metal that is highly toxic to humans.
Larger, older fish tend to have more mercury than younger fish. Fish that eat other fish have the most mercury. o In the ocean, these include sharks and swordfish. o In lakes and rivers, bass generally have the highest levels of mercury.
A large overdose of inorganic mercury may cause massive blood and fluid loss, kidney failure, and likely death. Chronic brain damage from organic mercury poisoning is difficult to treat. Some people never recover, but there has been some success in people who receive chelation treatment.
You can eat tuna regularly in moderation as part of a healthy and balanced diet. Canned tuna, particularly yellowfin and skipjack varieties that is caught using sustainable pole-and-line methods, is naturally low in mercury.
The Dietary Guidelines for Americans states that to consume those higher amounts, children should only be fed fish from the “Best Choices” list that are even lower in mercury – these fish are anchovies, Atlantic mackerel, catfish, clams, crab, crawfish, flounder, haddock, mullet, oysters, plaice, pollock, salmon, ...
Worst: Fish High in Mercury
Fish Low in Mercury:
Symptoms of organic mercury poisoning from long-term exposure include:
Fish and shellfish in this category — such as salmon, catfish, tilapia, lobster and scallops — are safe to eat two to three times a week, or 8 to 12 ounces per week, according to the FDA.
The total mercury content in 60 samples of canned tuna was determined, with an average concentration of 0.138 ± 0.218 mg/kg wet weight. The maximum was 0.858 and the minimum 0.010 mg/kg wet weight.
Exposure to mercury – even small amounts – may cause serious health problems, and is a threat to the development of the child in utero and early in life. Mercury may have toxic effects on the nervous, digestive and immune systems, and on lungs, kidneys, skin and eyes.
Symptoms of poisoning can include:
The Heavy metal test is a group of tests that measure the levels of four potentially harmful metals (Arsenic, Cadmium, Lead, and Mercury). The myLAB Box at home heavy metals test kit is used to find out if you have been exposed to certain metals, and how much of the metal is in your system.