title: Meta-analysis of the effect of β-glucan intake on blood cholesterol and glucose levels.
abstract: OBJECTIVE
  A meta-analysis was performed on epidemiologic studies to assess the relation between β-glucan consumption from oats and from barley on blood cholesterol level, triglyceride/triacylglycerol (TGL/TAG) level, and blood glucose level (BGL) in humans. In addition, the effect of β-glucan on total cholesterol (TC) and BGL was translated into an empirical dose-response model.
  
  
  METHODS
  Thirty research articles that evaluated the effect of different exposure levels of β-glucan on blood cholesterol and BGL were analyzed, yielding 126 clinical studies.
  
  
  RESULTS
  There was a significant inverse relation in TC (-0.60 mmol/L, 95% confidence interval [CI] -0.85 to -0.34), low-density lipoprotein (-0.66 mmol/L, 95% CI -0.96 to -0.36), and TGL/TAG (-0.04 mmol/L, 95% CI -0.15 to 0.07) after consumption of β-glucan. In contrast, an increase in high-density lipoprotein cholesterol was noted (0.03 mmol/L, 95% CI -0.06 to 0.13) with the random-effect model. The analysis showed a significant change in BGL (-2.58 mmol/L, 95% CI -3.22 to -1.84) with high heterogeneity between (I(2) = 97%) and across (τ(2) = 5.88) the studies. The fixed-effect model showed a significant change in TC, low-density lipoprotein, and BGL, whereas it showed no significant changes in high-density lipoprotein and TGL/TAG. The dose-response model showed that a 3-g/d dose of oat or barley β-glucan was sufficient to decrease TC.
  
  
  CONCLUSIONS
  Consumption of 3 g/d of oat or barley β-glucan is sufficient to decrease blood cholesterol, whereas the effect on BGL is still inconclusive, with high heterogeneity, and requires further clinical research studies with longer intervention periods.
authors.affiliation: Institute of Food and Health, School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland.
authors.forename: Uma
authors.initials: U
authors.lastname: Tiwari
authors.forename: Enda
authors.initials: E
authors.lastname: Cummins
mesh_terms: D018554:Avena / Q000737:chemistry*; D001786:Blood Glucose / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D004305:Dose-Response Relationship, Drug; D001467:Hordeum / Q000737:chemistry*; D006801:Humans; D010936:Plant Extracts / Q000494:pharmacology*; D014280:Triglycerides / Q000097:blood*; D047071:beta-Glucans / Q000494:pharmacology*
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D010936:Plant Extracts; D014280:Triglycerides; D047071:beta-Glucans; D002784:Cholesterol