title: Effect of supplementation with high-selenium yeast on plasma lipids: a randomized trial.
abstract: BACKGROUND
  High selenium status has been linked to elevated blood cholesterol levels in cross-sectional studies.
  
  
  OBJECTIVE
  To investigate the effect of selenium supplementation on plasma lipids.
  
  
  METHODS
  Randomized, placebo-controlled, parallel-group study stratified by age and sex. Participants, research nurses, and persons assessing outcomes were blinded to treatment assignment. (International Standard Randomised Controlled Trial Number Register registration number: ISRCTN25193534)
  
  
  METHODS
  4 general practices in the United Kingdom.
  
  
  METHODS
  501 volunteers aged 60 to 74 years.
  
  
  METHODS
  Participants received selenium, 100 mcg/d (n = 127), 200 mcg/d (n = 127), or 300 mcg/d (n = 126), as high-selenium yeast or a yeast-based placebo (n = 121) for 6 months.
  
  
  METHODS
  Total and high-density lipoprotein (HDL) cholesterol concentrations were measured in nonfasting plasma samples stored from participants in the UK PRECISE (United Kingdom PREvention of Cancer by Intervention with SElenium) Pilot Study at baseline (n = 454) and at 6 months (n = 394). Non-HDL cholesterol levels were calculated.
  
  
  RESULTS
  Mean plasma selenium concentration was 88.8 ng/g (SD, 19.2) at baseline and increased statistically significantly in the treatment groups. The adjusted difference in change in total cholesterol levels for selenium compared with placebo was -0.22 mmol/L (-8.5 mg/dL) (95% CI, -0.42 to -0.03 mmol/L [-16.2 to -1.2 mg/dL]; P = 0.02) for 100 mcg of selenium per day, -0.25 mmol/L (-9.7 mg/dL) (CI, -0.44 to -0.07 mmol/L [-17.0 to -2.7 mg/dL]; P = 0.008) for 200 mcg of selenium per day, and -0.07 mmol/L (-2.7 mg/dL) (CI, -0.26 to 0.12 mmol/L [-10.1 to 4.6 mg/dL]; P = 0.46) for 300 mcg of selenium per day. Similar reductions were observed for non-HDL cholesterol levels. There was no apparent difference in change in HDL cholesterol levels with 100 and 200 mcg of selenium per day, but the difference was an adjusted 0.06 mmol/L (2.3 mg/dL) (CI, 0.00 to 0.11 mmol/L [0.0 to 4.3 mg/dL]; P = 0.045) with 300 mcg of selenium per day. The total-HDL cholesterol ratio decreased progressively with increasing selenium dose (overall P = 0.01).
  
  
  CONCLUSIONS
  The duration of supplementation was limited, as was the age range of the participants.
  
  
  CONCLUSIONS
  Selenium supplementation seemed to have modestly beneficial effects on plasma lipid levels in this sample of persons with relatively low selenium status. The clinical significance of the findings is unclear and should not be used to justify the use of selenium supplementation as additional or alternative therapy for dyslipidemia. This is particularly true for persons with higher selenium status, given the limitations of the trial and the potential additional risk in other metabolic dimensions.
  
  
  BACKGROUND
  The Cancer Research Campaign (now Cancer Research UK) and the University of Surrey.
authors.affiliation: University of Surrey, Guildford, United Kingdom. m.rayman@surrey.ac.uk
authors.forename: Margaret P
authors.initials: MP
authors.lastname: Rayman
authors.forename: Saverio
authors.initials: S
authors.lastname: Stranges
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Griffin
authors.forename: Roberto
authors.initials: R
authors.lastname: Pastor-Barriuso
authors.forename: Eliseo
authors.initials: E
authors.lastname: Guallar
mesh_terms: D000368:Aged; D002784:Cholesterol / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D003430:Cross-Sectional Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012643:Selenium / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*; D015002:Yeast, Dried
chemical_list: D008076:Cholesterol, HDL; D002784:Cholesterol; D012643:Selenium