Do you know what are the health consequences of eating foods with mercury (mainly fish)? What are its effects on our body? We discover it for you.
Until a few years ago, the consumption of tuna below 100 grams in children under 3 years of age and in pregnant women. But shortly after he made an update of this recommendation: not advising the consumption of bluefin tuna neither in children under 3 years nor in pregnant and lactating women.
The reason? Very simple: the existence of mercury in tuna , and not only in tuna, but in those large species that, being located at the top of the sea food chain, tend to accumulate mercury in their different fatty tissues , which absorb of their prey in its most toxic form (methylmercury).
What is mercury?
The mercury is an element that is present naturally in not only water but also in the air and soil. We find it mainly in different forms: elemental (metallic), inorganic and organic. It is this last form where we distinguish methylmercury, which we consume and therefore penetrates our body through food.
Mercury can actually come naturally (in the earth’s crust or come from volcanic activity or rock erosion). And also from the human activity itself. It is precisely the mercury emissions originating mainly from industrial processes or the combustion of coal in power plants, which finally end up being transformed into methylmercury from the action of certain bacteria.
This is when it tends to accumulate in both fish and shellfish, accumulating especially at high levels in large predatory fish, which throughout their lives have eaten many small fish that, in turn, have ingested methylmercury by feeding on plankton. Present in the rocks.
For this reason, the main routes of exposure for people are the consumption of fish and shellfish contaminated with methylmercury. And, contrary to popular belief, cooking food does not remove the mercury found in it.
What are the effects of mercury on our body?
We must bear in mind that we are all exposed to any form of mercury. In most cases these are low levels. But in certain situations or stages of life, these levels can be worrying and dangerous, even when they are precisely small amounts.
Effects on the fetus during pregnancy
For example, fetuses are very sensitive to the effects of mercury on development, so an exposure of the pregnant woman to methylmercury can cause damage to the brain and nervous system of the fetus, especially when it is in full growth.
The main reason is that this compound is able to cross both the placental barrier and the blood-brain barrier with some ease, and may affect the normal development of the fetus.
That is, the consumption of foods with methylmercury even in small amounts by pregnant women can affect the development of the baby, especially memory, concentration, cognitive thinking, motor skills and fine spatial-visual skills.
Furthermore, it is known to cause chromosomal alterations that ultimately lead to mental and physical disorders.
Effects in adults
The symptoms appear mainly in the long term, when the intake has been constant.
In any case, as many studies have shown, mercury is known to increase the risk of heart attack and affect the liver, brain, kidneys, and spinal cord. On the other hand, it affects the circulatory system and the IARC (International Agency for Research on Cancer) has classified methylmercury in Group 2B; ie “possibly carcinogenic to humans”.
In what foods do we find mercury?
As we indicated previously, the fish that are higher up the food chain are the ones that present the greatest amount of mercury in their body. That is, we find it especially in the largest fish.
For example, the large tuna stands out (or Bluefin tuna, which we must differentiate from the small tuna that is used for canning and preserves), swordfish, marlin, king mackerel, pike, barracuda, walleye, toothed whales and seals.
As we can see, according to the recommendations made by official and specialized entities, the consumption of these foods should be avoided during pregnancy and young children.