Fish should actually be on the menu regularly because of its healthy ingredients such as vitamins, trace elements and nutrients. However, some types of fish can contain mercury compounds that pose a risk to the offspring during pregnancy and breastfeeding.
The Federal Institute for Risk Assessment (BfR) therefore points out in a recent communication that pregnant and breastfeeding women should avoid fish species with high levels of methylmercury. In principle, the intake of mercury compounds can be minimized by choosing the right types of fish.
Mercury in fish
Although fish provides vitamin D, iodine and omega-3 fatty acids, among others, which are associated with beneficial health effects, mercury exposure is a growing problem.
The mercury compound methylmercury (MeHg) accumulates in fish and also in mussels, crabs and squid. This compound is created when certain bacteria absorb inorganic mercury compounds from rivers, lakes and seas and convert them into organic compounds, reports the BfR.
Methylmercury then accumulates in fish and seafood via the food chain and eventually enters the human body when the animals are consumed, which could pose a health risk.
Methylmercury contamination determined
The BfR is now examining the contamination we are actually exposed to through fish consumption using data from the so-called BfR-MEAL study on the methylmercury levels of various types of fish and the respective consumption quantities.
For the BfR MEAL study, food was purchased and prepared in a typical household manner. The fish was baked, steamed or fried, explains the BfR. The content of desirable and undesirable substances was then determined.
By comparing these data with the consumption amounts in the population, the experts were then able to draw conclusions about the actual intake of the mercury compound.
Which fish is heavily contaminated?
In general, the highest methylmercury levels are found in large and older predatory fish due to accumulation via the food chain. Tuna, spiny dogfish and redfish were the fish species with the highest methylmercury levels in the BfR MEAL study.
Although pollock is significantly less contaminated, according to the BfR it still contributes the most to the population's methylmercury intake because this fish is eaten so much. For example, pollock is contained in fish fingers and many other ready-made fish meals from the freezer.
Avoid certain types of fish
“The intake of methylmercury can be reduced, for example, by eating less fish species with particularly high levels,” emphasises BfR President Professor Andreas Hensel.
This is especially important for pregnant and breastfeeding women, as scientific studies have shown that methylmercury can impair the neurological development of offspring.
Overall risk low
Despite the proven contamination, the BfR concludes that the average amount of methylmercury consumed in all age groups is below the tolerable amount.
This health-based guideline value is given by the European Food Safety Authority (EFSA) as 1.3 micrograms of methylmercury per kilogram of body weight per week and if adhered to, no adverse health effects are to be expected.
In relation to body weight, the researchers recorded the highest intake levels of methylmercury in adolescents and young adults between the ages of 14 and 25. In addition, in all age groups, those who ate tuna absorbed particularly high amounts of methylmercury.
The positive conclusion, however, is that the intake of the mercury compound can be significantly reduced by choosing fish species with lower methylmercury levels. This means that you can benefit from the health advantages of eating fish without putting your own health at risk. (fp)