|Image 1: Selenium is a naturally occurring mineral |
involved in a host of metabolic processes.
Based on observations with other antioxidants and the well-established involvement of selenium in the activation of the master-antioxidant glutathion, researchers from the Selcuk University in Konya, Turkey, hypothesized that supplementation with yet to be determined amounts of selenium might ameliorate the detrimental effects of arduous exercise (Akil. 2011). To verify their hypothesis, the Akil et al. subjected a group of 4-6 month old Sprague-Dawley rats to one out of four treatments for 4 weeks:
- group 1: unsupplemented sedentary control
- group 2: selenium supplemented, sedentary control
- group 3: swimming control (30 minutes in a closed glass-swimming pool; 50x50cm)
- group 4: selenium supplemented + swimming (same as group 3)
For more on the beneficial effects high doses of selenium may have and a short discussion of toxicity issues, see my previous post on "NAC + Zinc + Selen = Silver Bullett Against Mercury Poisoning"As the data in figure 1 shows, the non-supplemented arduously exercising rats (group 3) had by far the highest malondialdehyde (MDA is an accepted marker of unwanted oxidation) levels. On the other hand, the MDA levels of the supplemented group were reduced by 11%. Compared to the sedentary controls, which had identical (i.e. within the statistical margin) MDA levels, the malondialdehyde content of their brains was still elevated by 57%. While selenium supplementation may thus have ameliorated the increase in brain MDA levels, it was not able to completely protect the rat-brains from free-radical induced oxidation processes.
|Figure 1: Malondealdehyde (MDA) and glutathione levels in rat brains after 30 minutes of exhaustive swimming exercise (data adapted from Akil. 2011)|
While it would have been nice to see a comparison of the effects of different doses and exercise protocols, the study at hand is just another hint a the importance of a mineral, that was believed to be toxic up to the late 1950. Consequently, this is neither the first, nor will it be the last time you read about this extraordinary mineral on the SuppVersity - stay tuned for more!