Salmon, tuna, cod, sardines… While it is valuable for health, fish remains our primary source of dietary exposure to methylmercury. It can also be a vector of PCBs and dioxins toxic to the brain. Which species are the least contaminated? What quantities should not be exceeded? Which ones to avoid during pregnancy, breastfeeding and in children? Answers.
Fished at sea, river or lake, the fish is subject to contaminants which, depending on the doses ingested, are dangerous to health. The one that has been talked about the most in recent years (because its concentration continues to increase in the oceans) is mercury. Or rather “methylmercury” since it is in this form that it is present in water and then concentrates more or less strongly in aquatic organisms. “Mercury exposureeven in small amounts, can cause serious health problems and poses a threat to the development of the child in utero and at an early age”states theWHO. It can be toxic to the nervous, digestive and immune systems, but also to the lungs, kidneys, skin and eyes. “This substance can thus cause behavioral problems light or developmental delays in childreneven in the absence of toxic signs in the mother”, argues the National Food Safety Agency (handles) before recognizing that “Fish consumption is the main source of human dietary exposure to methylmercury”.
PCBs (polychlorinated biphenyls) also contaminate our fish… and us when we eat them. These chlorinated aromatic compounds used in industry were banned more than 20 years ago in France, but persist in the environment. Exceedances of these levels in freshwater fish have been observed in several French rivers. Since 2006, fishing restrictions and recommendations not to consume the most PCB-accumulating fish species have been taken. The consumption of certain fish should be avoided by women of childbearing age since the main critical effects of PCBs relate to mental and motor development in children exposed during pregnancy or breastfeeding.
Third contaminant under surveillance in fish: dioxins. Dioxins bring together nearly 200 different molecules that can disrupt the reproductive system, even at the lowest doses. They accumulate particularly in the fatty tissues of fish and crustaceans. They can also be found in milk, dairy products and eggs. Even if “the exposure of the French to these substances has fallen sharply over the past ten years”, indicates ANSES, “food constitutes (still) more than 90% of the total exposure of the general population”.
It is therefore important to know the potential contaminants present in the fish in order to make the right choices at the time of purchase… And not to go too far in banishing them. Remember that they contain three essential elements for our health: iodine, selenium and omega-3 fatty acid. “Without forgetting high protein content and a lower level of cholesterol compared to red meat adds biologist Barbara Demeneix in her book “Toxic Cocktail” (Editions Odile Jacob).
- Selenium activates the thyroid hormone and protects the body from mercury by capturing it and promoting its elimination.
- iodine is a trace element that allows the synthesis of thyroid hormones. The secretion of these hormones begins from the beginning of the life of the fetus and participates in the vital functions of the organism, in particular in neurological development.
- Omega-3 fatty acids are necessary for the development and functioning of the retina, brain and nervous system.
To remember :
|