How Does Mercury Get into Tuna and Other Seafood?
The primary cause for the levels of mercury in the fish we consume is the number of industrial pollutants that enter our oceans every day, from coal plants, mines, and from natural sources such as volcanoes. Mercury is converted to methylmercury when it reaches our oceans and wetlands. Methylmercury is quickly and efficiently absorbed by fish’s bodies. The mercury bioaccumulates in the organisms of fish in the same way it does in humans, and it is passed through the food chain, starting with small fish and plankton.
The longer a species of fish lives, along with how high it is on the food chain, the more mercury it will contain. The fish that eat other fish like Tuna and Swordfish and different types such as Barracuda is the worst. Our oceans are very polluted, and we are eating fish with extremely high mercury levels.
How Does Mercury Affect your Body?
Mercury is a heavy metal, much like iron and zinc. However, unlike iron and zinc, it has no positive function in the human body. On the other hand, it can have numerous adverse effects on the brain and kidneys. Mercury is either excreted by the body in feces or enters the bloodstream, where it heads to the kidneys and brain. The kidneys can store mercury in a non-toxic form by binding it with a protein contained in them called metallothionein. The body can cope with moderate levels of mercury, as long as the dosage does not overwhelm the system. If the body stores too much mercury in a short space of time, this can lead to mercury toxicity.
There is a limit to the amount of mercury, the body will store in a year; however, after which it will be excreted.
Alternatively, mercury can also travel to the brain. If mercury does go to the brain, it crosses the blood-brain barrier. Once it does this, it can cause neurological problems. It can do so as methylmercury binds to cysteine and looks to the brain as a common amino acid. This process can luckily be inhibited by neutral abundant amino acids, provided – as before – that the system is not overwhelmed by the amount of methylmercury in the body. Symptoms of high-level methylmercury exposure include “signs of madness,” lack of coordination, and muscle weakness, along with altered vision, speech, and hearing.
It is especially damaging to the brain and nervous system if exposure to mercury happens in the womb. It is therefore recommended that women who are pregnant limit the amount of seafood they eat, specifically tuna, swordfish, and oysters. Intake of tuna should also be strictly regulated for young children, women of childbearing age who plan to have children shortly, and those who have been deemed at risk of mercury poisoning.
So here are some tips to help you understand what you are consuming.