Levels of the minerals did not affect the risk of abnormal blood sugar metabolism (dysglycemia) in women, however, according to findings published in Nutrition & Metabolism.
“We need to identify the optimal range of selenium status and intake that will minimize potential adverse effects on glucose metabolism while optimizing type 2 diabetes prevention,” wrote the researchers, led by Tasnime Akbaraly from the University of Montpellier I.
“This may allow us to target a population that might benefit from selenium supplementation.”
Europe versus America
The study is of added importance in Europe where selenium levels have been falling Europe since the EU imposed levies on wheat imports from the US, where soil selenium levels are high.
As a result, average intake of selenium in the UK has fallen from 60 to 34 micrograms per day, leading to calls from some to enrich soil and fertilizers with selenium to boost public consumption. Selenium-enriched fertilizers are used in Finland.
The European recommended daily intake (RDI) is 65 micrograms. The recommended EC Tolerable Upper Intake Level for selenium is 300 micrograms per day.
Akbaraly and her co-wokrers followed 1,162 healthy French men and women for nine years and documented 70 new cases of dysglycemia in men and 57 cases in women.
The average selenium blood level at the start of the study was 1.08 micromoles per litre in men and 1.1 micromoles per litre for women. Men with the highest selenium levels (1.19-1.97 micromoles per litre) were 50 per cent less likely to develop dysglycemia than men with the lowest average levels.