Selenium is an essential mineral for the proper functioning of our body. We obtain it through food and it exercises various biological functions, mainly antioxidants . It also acts on the thyroid system and is involved in lipid metabolism .
Consumption of adequate amounts of this micronutrient has been linked, inter alia, to reproduction and protection against infection and cancer , although there is not yet sufficient scientific evidence to support the existence of an anti-cancer effect.
The daily amount recommended by the European Federation of Dietitian Associations (EFAD) is between 50 and 60 micrograms from food, for both men and women of legal age. ” In minors the recommended concentrations vary according to the stage of growth and in pregnant or lactating women they can also be increased,” says Rafael Birlanga, member of the Board of Directors of the Official College of Dietitians and Nutritionists of the Valencian Community ( Codinucova) .
Foods rich in selenium
Selenium is present in various types of food, but not always in the same proportion. The dietitian-nutritionist explains that it is a mineral “that we find in the earth or in the waters of the different regions”, so that its concentration will be greater in the food obtained in regions whose soils and waters are richer in it.
Given that ” in Spain no selenium-poor land areas have been detected , there should be no problem in reaching the daily intake recommendations established by EFAD.”
There is no specific food or group that stands out especially for its selenium content, but the following products in which it has a greater presence can be mentioned:
- Whole grains.
- Fishand seafood.
- Carnes.
- Some types of vegetables(onion, asparagus).
- Seeds like sunflower seeds.
- Nuts like brazil nuts.
Birlanga asserts that a varied diet based on healthy foods will guarantee, except in specific cases, the daily contribution of selenium. The guideline would be as follows: “A base of seasonal fruits and vegetables and proximity , where we prioritize that cereals are whole and that our protein sources are of quality through legumes, eggs, local fish and lean meats”.
Consequences of deficiency or excess selenium
Under normal circumstances, selenium deficiency is rare and will manifest in heart damage and stiffness, swelling, or joint pain. “Toxicity from excess of this mineral is even rarer, because it is unlikely to occur through food,” says the dietitian-nutritionist. However, it could be caused by ” supplementation with selenium without sanitary supervision ” and the consequences would be “changes in the skin, loss of teeth and digestive and neuronal disorders”.
What role does this mineral play in cancer prevention?
In light of the antioxidant effect of selenium and the various epidemiological studies that show its relationship with cancer prevention, it could be concluded that this micronutrient has a powerful anticancer effect.
But because the scientific evidence does not get along well with generalizations, cancer research and nutrition experts prefer not to speak out before having stronger results. One of the teams investigating the relationship between selenium and cancer prevention is the Molecular and Genetic Epidemiology Group of the National Center for Oncological Research (CNIO) , to which Esther Molina and Núria Malats belong. ” There is no evidence today about the possible anti-cancer effect of selenium , and it is necessary to carry out studies evaluating this association,” the scientists declare.
His group is exploring “the association of mineral micronutrients with the risk of developing pancreatic cancer in the framework of a European multicenter study that we are leading and involving 28 centers from six European countries.” To do this, they have measured the levels of various micronutrients in the nails and have the objective of “analyzing this association considering genetic and lifestyle information “.
