Selenium status in Greenland Inuit

Abstract

In Greenland, the human intake of selenium has always been relatively high and is closely connected to intake of the traditional food of marine origin. Analyses of historic and present day human and animal hair samples have indicated that the selenium level in the marine environment has been constant over time, while the levels in humans have declined corresponding to a decrease in intake of traditional food. The Inuit population in Greenland is in dietary transition where western-style food will increasingly dominate. As a consequence, the ample supply of selenium may not be sustained in the future. We report here the selenium status in three Greenlandic population groups, Ittoqqortoormiit and Tasiilaq on the east coast and Uummannaq on the west coast. Mean whole blood concentrations ranged from 178 μg/l in Tasiilaq men to 488 μg/l in Uummannaq men. Plasma concentrations ranged from 79 μg/l in Tasiilaq women to 113 μg/l in Uummannaq men. With increasing Se concentrations in whole blood, the plasma concentrations increased but tended to stabilise a level approximately 140 μg/l. Selenium blood levels were highly significantly correlated with long chain marine fatty acids. Dietary survey and food composition data from the west coast showed that whale skin, muktuk, is the main source of Se followed by birds, seal meat and organs, and fish. Terrestrial animals contributed only insignificantly to the selenium intake. In West Greenland, daily Se intake (235 μg/day) was estimated by dietary survey; it corresponded well with a calculated intake (220 μg/day) based on the mean blood concentration.