Nutrition Videos

Through my channel's comments, many people mention again and again the problem with formaldehyde in farmed fish. Formaldehyde is a particularly toxic substance that is used extensively in fish farming, in order to clean the fish from parasites. Could this be dangerous for our health? Should we avoid farmed fish? By the end of this video, you'll know. I'm very familiar with formaldehyde from my first year in medical school, because we protect corpses from decay in a formaldehyde solution. Formaldehyde is a strong anti-parasitic substance that kills all germs that threaten to decompose a dead tissue. Formaldehyde is used extensively in fish farming, in order to kill parasites and allow the fish to survive in a really small area. In nature, fish are very far from each other and if one of them is infected with germs, it will die or kill them, before it infects other fish too. But when fish live too close to each other and one of them is infected with germs, all of them will become infected really soon. If we don't intervene using substances like formaldehyde, all of them will die. Formaldehyde is a known to be a strong carcinogen and its consumption is associated with really negative effects on our health. Therefore, this should be a problem indeed concerning the consumption of foods in which formaldehyde has been used, in order to clean them. Is it so? The positive aspect is that formaldehyde has a very short half-life. Essentially, this means that it's dissolved really fast after it comes into contact with the fish. Namely, after the fish are immersed in a formaldehyde solution and then washed, almost all formaldehyde is removed. Even the smallest residue of formaldehyde that remains in the fish has been dissolved within two or three days the most. Therefore, this is rather safe. If the fish farmer uses formaldehyde in order to wash the fish and kill the parasites, and then washes them with fresh water and return them to their place within a few days, there will be no formaldehyde in their body. It's like we wash ourselves with soap and then we wash it off. If I don't drink the soap water, I'll be okay. As will be the one who'll eat me. Therefore, are farmed fish entirely safe? Not entirely. Unfortunately, in some cases, fish farmers use formaldehyde solutions after they collect the fish and before they sell them, in order to preserve them for more days without them going bad. This is a crime, because it has very negative effects on our health. On the other hand, some fishermen unfortunately do the same. They fish with their boat and until they go to the market, they spray the fish with a formaldehyde solution, in order to preserve them. In this way, they seem fresher and they can stand lower temperatures, so that they don't go bad. So they sell them more easily, without them smelling bad. Therefore, the formaldehyde problem does not only concern fish farming. On the contrary, it concerns fish in general. You may make a reasonable question: Is there no control? There is, but things are more complicated than they seem. After they die, fish produce formaldehyde themselves. So it's often hard to find out if the formaldehyde has been added by a producer or a seller in order to preserve the fish, or if it's the formaldehyde that the fish naturally releases when it dies. Have I confused you? There are no easy answers. What you can do, which is also what I do, is to get to know your local fishmonger, to talk to them, to share your concerns with them, to tell them about your kids, that you're concerned about their health, to ask about their kids too. In a few words, to develop a trusting relationship that you will take care of. In this way, they will probably take care of you too. Them may tell you "Leave that fish, I have good mackerel today." If you're interested, I've made a video that compares the nutrients of farmed fish and pelagic fish that's worth watching. Thank you very much!