Selenium. What is this for? Several proteins in the body contain selenium and some of these are antioxidants, i.e they keep free radicals from hurting our cells. Selenium is so important for fertility, that when it is lacking in the testis, it is kidnapped from the brain! (go figure out the organs hierarchy in men!). However this is a tough call because the brain seriously needs selenium and when the levels are low, there can be psychiatric disorders such as schizophrenia.
Selenium is found in crops, but New Zealand soil (therefore food) is found to be particularly poor of it. Brazil nuts are very rich in selenium, as are sunflower seeds, barley, brown rice, and…sardines, herrings, salmon and mackerel……
And what a coincidence! Selenium in the fish is also making it safe to eat. Regardless of mercury!
Thanks to this element, fish carrying mercury is not a danger, neither for adults nor for babies. In the course of the last decades, scientists proved that most fish is very safe because it contains a good amount of selenium. What is the explanation? Mercury is only toxic when it binds to our selenium in the body but if there is a good amount of this other strange but essential element in the food, the problem does not exist. This is the case for most types of fish, with the exception for swordfish, king mackerel and whale meat (which luckily is normally eaten only in few countries). However, some freshwater fish have relatively high mercury levels along with low selenium levels. So careful with those.
The mercury fear of the 80s spread like a mania and unfortunately kept (and still keeps) many people away from good seafood as from a pest. The worry was because mercury is very toxic to the brain in all people and deeply affects development of a baby in the womb. Unfortunately, sometimes the recommendations (even from government agencies) are not quite correct and can even be harmful. In fact, many pregnant ladies are still worried to eat fish, and to cook it for their children. Mothers are very aware of the delicate phase of the baby’s and child’s growth and are often very careful of what they eat or feed their children with. It is unfortunate however that many still follow the early advices to stay away from fish (especially during pregnancy) because what is harmful, instead, is eating little or no fish: research found that fish in the mother’s nutrition prevents future impairment of communication skills and verbal IQ in the baby, and throughout adolescence. Fish in fact offers selenium AND omega 3, both essential for a proper development of the brain.
Moreover, even modest fish consumption in all people (1-2 servings of fatty fish per week) results in as much as 36% reduction of deaths from heart disease.
Fish that are completely safe to consume and that carry with them not only a good amount of selenium to silence the toxicity of mercury but also a high dose of omega 3 are sardines, anchovies, herrings, mackerel, wild-caught salmon; these are also the fish that are the most ecologically sustainable in front of the exhaustion or significant decline of most fisheries of the world. If you do not want to exacerbate the pressure on the oceans, this is a choice that you can easily make. And it comes with a best reward, the rich content of protective omega 3.
Laura Sanders , 2015. When selenium is scarce, brain battles testes for it Mice studies reveal dueling demands for essential nutrient, in Science News, https://www.sciencenews.org/article/when-selenium-scarce-brain-battles-testes-it?tgt=nr
M. Pitts et al. 2015 Competition between the brain and testes under selenium-compromised conditions: Insight into sex differences in selenium metabolism and risk of neurodevelopmental disease. Journal of Neuroscience. Vol. 35, November 18, p. 15326. doi: 10.1523/JNEUROSCI.2724-15.2015
Kresser, C. 2014. 5 Reasons Why Concerns About Mercury in Fish Are Misguided, http://chriskresser.com/5-reasons-why-concerns-about-mercury-in-fish-are-misguided/