The Least Contaminated Fish: Salmon, Tuna?

Salmon, tuna, cod, sardines… Although fish is valuable for health, it remains our main source of dietary methylmercury intake. It can also be a vector for brain-toxic PCBs and dioxins. Which species are least affected? Which amounts should not be exceeded? Which should be avoided during pregnancy, breastfeeding and in children? Reply.

Fished in the sea, river or lake, The fish are exposed to pollutants which are hazardous to health depending on the dose ingested. The mercury that has been the most talked about in recent years (because its concentration in the oceans continues to increase) is mercury. Or rather “methylmercury”, since it occurs in water in this form and then accumulates to a greater or lesser extent in aquatic organisms. mercury exposureeven in small amounts, can cause serious health problems and endanger the development of the unborn child and at a young age.”, explains the WHO. It can be toxic to the nervous, digestive, and immune systems, as well as to the lungs, kidneys, skin, and eyes. “So this substance can cause behavioral problems light or developmental delays in childreneven without toxic signs in the mother”, argues the National Food Security Agency (Anses) before acknowledging it “Fish consumption is the major source of dietary human 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 in France more than 20 years ago, but they remain in the environment. Freshwater fish exceeding these values ​​have been observed in several French rivers. Since 2006, catch restrictions and recommendations not to consume PCB-accumulating fish species have been in place. Consumption of certain fish should be avoided by women of childbearing potential since the main critical effects of PCBs are on the mental and motor development of children exposed during pregnancy or lactation.

Third monitored contaminants in fish: dioxins. Dioxins combine nearly 200 different molecules that can disrupt the reproductive system, even at the lowest doses. They accumulate particularly in the fatty tissue of fish and crustaceans. They are also found in milk, dairy products and eggs. Even if “The exposure of the French to these substances has fallen sharply over the past decade”, indicates ANSES, “Food (still) accounts for more than 90% of the total exposure of the general population”.

It is therefore important to be aware of the potential contaminants in fish in order to make the right choice when purchasing… And not to go too far in trying to banish them. Remember that they contain three essential elements for our health: Iodine, selenium and omega-3 fatty acids. “Without forgetting high protein content and a lower cholesterol level compared to red meat adds the biologist Barbara Demeneix in her book “Toxic Cocktail” (Odile Jacob editions).

  • selenium activates thyroid hormone and protects the body from mercury by trapping mercury and promoting its elimination.
  • iodine is a trace element that enables the synthesis of thyroid hormones. The secretion of these hormones begins at the beginning of the life of the fetus and is involved in the vital functions of the organism, especially in neurological development.
  • Omega-3 fatty acids are necessary for the development and function of the retina, brain and nervous system.

Recall :

  • You should eat fish once or twice a week.
  • It is necessary to give preference to small fish, less contaminated.
  • Oily fish should be skinned to reduce absorption of most contaminants present.

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