title: Comparative effects of two different forms of selenium on oxidative stress biomarkers in healthy men: a randomized clinical trial.
abstract: Epidemiologic and laboratory studies indicate that dietary selenium protects against prostate cancer. Results from clinical trials suggest that selenium-enriched yeast (SY) but not selenomethionine (SeMet) may be effective at reducing prostate cancer risk. Our objectives were to directly compare for the first time the effects of SeMet and SY on prostate cancer relevant biomarkers in men. We performed a randomized double blind, placebo-controlled trial of SY (200 or 285 μg/day) and SeMet (200 μg/day) administered for 9 months in 69 healthy men. Primary endpoints included blood levels of selenium-containing compounds and oxidative stress biomarkers [urine 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-iso-prostaglandin-F2α (8-iso-PGF2α) and blood glutathione (GSH)]. Secondary endpoints included plasma glucose and PSA levels. Compliance was high in all groups (>95%). Plasma selenium levels were increased 93%, 54%, and 86% after 9 months in SeMet and low- and high-dose SY groups, respectively, and returned to baseline levels after a 3-month washout (P < 0.05). Levels of 8-OHdG and 8-iso-PGF2α were decreased 34% and 28%, respectively, after 9 months in the high-dose SY group (P < 0.05). These decreases were greatest in individuals with low baseline plasma levels of selenium (<127 ng/mL). No changes in serum PSA or blood glucose and GSH were observed. Overall, we showed for the first time, reductions in biomarkers of oxidative stress following supplementation with SY but not SeMet in healthy men. These findings suggest that selenium-containing compounds other than SeMet may account for the decrease in oxidative stress.
authors.affiliation: Departments of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors.forename: John P
authors.initials: JP
authors.lastname: Richie
authors.affiliation: Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors.forename: Arun
authors.initials: A
authors.lastname: Das
authors.affiliation: Departments of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Calcagnotto
authors.affiliation: Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors.forename: Raghu
authors.initials: R
authors.lastname: Sinha
authors.affiliation: Penn State Hershey Cancer Institute Clinical Trials Office, Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors.forename: Wanda
authors.initials: W
authors.lastname: Neidig
authors.affiliation: Departments of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors.forename: Jiangang
authors.initials: J
authors.lastname: Liao
authors.affiliation: Departments of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors.forename: Eugene J
authors.initials: EJ
authors.lastname: Lengerich
authors.affiliation: Departments of Public Health Sciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors.forename: Arthur
authors.initials: A
authors.lastname: Berg
authors.affiliation: Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia.
authors.forename: Terryl J
authors.initials: TJ
authors.lastname: Hartman
authors.affiliation: Center for Clinical Research, Pennsylvania State University, State College, Pennsylvania.
authors.forename: Amy
authors.initials: A
authors.lastname: Ciccarella
authors.affiliation: Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors.forename: Aaron
authors.initials: A
authors.lastname: Baker
authors.affiliation: Division of Urology, Penn State University College of Medicine, Hershey, Pennsylvania.
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Kaag
authors.affiliation: Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey.
authors.forename: Susan
authors.initials: S
authors.lastname: Goodin
authors.affiliation: Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey.
authors.forename: Robert S
authors.initials: RS
authors.lastname: DiPaola
authors.affiliation: Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania. kelbayoumy@hmc.psu.edu.
authors.forename: Karam
authors.initials: K
authors.lastname: El-Bayoumy
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism* / Q000652:urine; D001786:Blood Glucose / Q000032:analysis; D019587:Dietary Supplements; D004311:Double-Blind Method; D005978:Glutathione / Q000378:metabolism; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects*; D017430:Prostate-Specific Antigen / Q000378:metabolism; D012643:Selenium / Q000008:administration & dosage* / Q000097:blood; D012645:Selenomethionine / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D012645:Selenomethionine; D017430:Prostate-Specific Antigen; D005978:Glutathione; D012643:Selenium