title: Effects of supplementation with selenium, as selenized yeast, in a healthy male population from New Zealand.
abstract: Selenium (Se) supplementation was tested in a group of healthy men from Auckland, New Zealnd with selenized yeast (Selplex, 200 μg/day) as the supplementation mode. A set of biomarkers, including DNA damage levels and seleno-antioxidant enzyme levels, were evaluated at pre- and postsupplementation time points. Supplementation produced significant increases in serum Se levels, red blood cell (RBC) thioredoxin reductase (TR) activity and peroxide-induced DNA damage, when the mean baseline serum Se level was 110 ng/ml. Those with higher baseline serum Se levels gained less serum Se and showed a significant reduction of RBC glutathione peroxidase (GPx) activity by supplementation. The optimum benefits of supplementation on DNA stability are observed when the serum Se level reaches between >120 and <160 ng/ml. However, the most significant observation was that those with highest baseline DNA damage benefit the most from Se supplementation, whereas those having lower baseline DNA damage are disadvantaged. A dose of 200 μg/day selenized yeast was also shown to be a safer supplementation option compared to a similar dose of selenomethionine (SeMet). This study highlights the requirement for prestratification of a population by standing serum Se level and baseline DNA damage level, before any Se supplementation is carried out.
authors.affiliation: Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
authors.forename: Nishi
authors.initials: N
authors.lastname: Karunasinghe
authors.forename: Dug Yeo
authors.initials: DY
authors.lastname: Han
authors.forename: Shuotun
authors.initials: S
authors.lastname: Zhu
authors.forename: He
authors.initials: H
authors.lastname: Duan
authors.forename: Yi-Ju
authors.initials: YJ
authors.lastname: Ko
authors.forename: Jie Fu
authors.initials: JF
authors.lastname: Yu
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Triggs
authors.forename: Lynnette R
authors.initials: LR
authors.lastname: Ferguson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004247:DNA / Q000097:blood / Q000187:drug effects; D004249:DNA Damage; D019587:Dietary Supplements; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D010545:Peroxides / Q000494:pharmacology; D012643:Selenium / Q000008:administration & dosage* / Q000097:blood; D019098:Telomerase / Q000097:blood; D015003:Yeasts
chemical_list: D010545:Peroxides; D004247:DNA; D005979:Glutathione Peroxidase; D019098:Telomerase; D012643:Selenium