Heavy metals: can eating fish pose a health risk ?

Métaux lourds : faut-il arrêter de manger du poisson ?

Arsenic, cadmium, mercury, lead… Health authorities have been warning for years about the presence of heavy metals in our environment. In particular, in fish. Should we therefore stop consuming some of them ?

"The entire population is concerned“, described Santé Publique France in July 2021, when publishing a study on French people's exposure to heavy metals. This work has notably made it possible to better understand the sources of exposure, particularly in terms of diet, particularly fish and seafood.

Fat and lean

Should they be banned ? No! Santé Publique France reminds us that these foods “have many nutritional qualities“. On the other hand, in order to reduce the consumption of products potentially affected by this bioaccumulation of metals, the public institution recommends “consuming fish twice a week, including oily fish, varying the species and fishing locations“. So “fatty” (mackerel, salmon, herring, sardines, tuna…) but also “lean”: cod, pollock, whiting, dab, sea bream…

Which fish are affected ?

In the scientific journal Toxicologie Analytique et clinique, Marie Martin from the Toxicology Laboratory at Raymond-Poincaré Hospital in Garches points out the fish likely to accumulate the metals in question "at potentially toxic concentrations". In this case: "large piscivorous fish, at the end of the food chain and rich in lipids". She cites:

hake; pike; swordfish; tuna; shark; mackerel.

What potential effects ?

The scientist adds that “the adverse health effects of consuming food or water contaminated with metals vary depending on the amount consumed, the duration of exposure, age“. And to list “an alteration of renal, hepatic, cognitive functions and reproductive capacity, hypertension, neurological changes, skin damage and cancers“.

Hence the need, as Santé Publique France concludes, “to maintain biomonitoring studies to monitor the evolution of exposures to metals and pursue measures aimed at reducing them“.