There are dozens of influencers obsessed with helping us choose the perfect can of tuna. The problem is that what they say doesn’t make much sense.
There is a fine line that connects volcanic eruptions, oil combustion, and waste incineration with our kitchens: mercury. A mercury that is produced in dozens of activities (mostly human), which ends up deposited in the waters, transformed into methylmercury by millions of microorganisms, stored in fish and, finally, in our stomach. It was only a matter of time before it became the huge food scandal it is today. Methylmercury also reaches social networks. The problem is so big that there is no shortage of experts and influencers that defend messages such as choosing cans of “tuna” over cans of “light tuna.” The music is that of institutions such as the European Food Safety Authority (EFSA) that recommends avoiding large fish; The lyrics hide many problems. At the end of the day, the viral message mixes correct intuitions, with more than debatable scientific evidence (it uses, to begin with, commercial classifications that do not have direct Spanish correspondence). This is not the first time that an idea that sounds good ends up giving us headaches. And why is that a problem? Because, like it or not, fish is a centerpiece of many diets. Not only for its protein contribution, but as a priority source of certain fats that are very difficult to replace by any other means (e.g. omega-3). The thing is, with all that, comes methylmercury. And exposure to methylmercury is a tricky thing: it can harm brain development and be toxic to the nervous system. In fact, it can cause symptoms such as tremors, memory loss, and cognitive dysfunctions. The most vulnerable groups are pregnant women, nursing mothers, babies and young children. Do all fish have the same amount of mercury? No, it doesn’t. According to the Spanish Agency for Food Safety and Nutritionthere are four really dangerous species: the swordfish or emperor, the bluefin tuna (Thunnus thynnus), the shark (dogfish, mako shark, dogfish, dogfish and blue shark) and pike. These are problematic in women who are pregnant or planning to be pregnant, nursing mothers and children under 10 years of age. In fact, AESAN recommends directly avoid its consumption. The rest of the species are not problematic for the effects of mercury: they are safe and healthy. And the AESAN recommends between three and four servings a week even in the at-risk population. And aren’t there more differences according to levels? That is, are there only dangerous and non-dangerous species? No no. It is true that each species contains a different amount of mercury. In fact, each copy has different levels. That’s where the problem comes from: we need simple ‘rules’ to help us deal with uncertainty. On a practical level, according to the available studies, we can only define species with low mercury content as those on this list: Pollock, Anchovy, Herring, Cod, Bacaladilla, Cockle, Mackerel, Squid, Shrimp, Crab, Cane, Coquina, Carp, Squid, Clam, Choco/Cuttlefish, Lobster, Coquina, Sea bream, Sprat, Prawn, Horse mackerel, Lobster, Prawn, European sole, Dab, Sea bass, Mussel, Merlan, Hake, Razor clam, Oyster, Pomfret, Flounder, Squid, Octopus, Shrimp, Atlantic salmon, Pacific salmon, Sardine, Sardinella, Sardinopa, Plaice, and Trout. Everything else has medium levels and making distinctions between them is impossible on a practical level. So it doesn’t make sense to follow these types of recommendations? In general, any attention we pay to food is good. The system is configured in such a way that, if we let ourselves goour diet gets worse. However, we know that Obsessing over diet is also full of problems.. Using heuristics that complicate the purchase without substantial improvements is not as good an idea as it seems. Image | Tobias Tullius In Xataka | The scientific reason why miracle diets don’t work is you
