title: Effect of a low-glycemic index or a high-cereal fiber diet on type 2 diabetes: a randomized trial.
abstract: BACKGROUND
  Clinical trials using antihyperglycemic medications to improve glycemic control have not demonstrated the anticipated cardiovascular benefits. Low-glycemic index diets may improve both glycemic control and cardiovascular risk factors for patients with type 2 diabetes but debate over their effectiveness continues due to trial limitations.
  
  
  OBJECTIVE
  To test the effects of low-glycemic index diets on glycemic control and cardiovascular risk factors in patients with type 2 diabetes.
  
  
  METHODS
  A randomized, parallel study design at a Canadian university hospital research center of 210 participants with type 2 diabetes treated with antihyperglycemic medications who were recruited by newspaper advertisement and randomly assigned to receive 1 of 2 diet treatments each for 6 months between September 16, 2004, and May 22, 2007.
  
  
  METHODS
  High-cereal fiber or low-glycemic index dietary advice.
  
  
  METHODS
  Absolute change in glycated hemoglobin A(1c) (HbA(1c)), with fasting blood glucose and cardiovascular disease risk factors as secondary measures.
  
  
  RESULTS
  In the intention-to-treat analysis, HbA(1c) decreased by -0.18% absolute HbA(1c) units (95% confidence interval [CI], -0.29% to -0.07%) in the high-cereal fiber diet compared with -0.50% absolute HbA(1c) units (95% CI, -0.61% to -0.39%) in the low-glycemic index diet (P < .001). There was also an increase of high-density lipoprotein cholesterol in the low-glycemic index diet by 1.7 mg/dL (95% CI, 0.8-2.6 mg/dL) compared with a decrease of high-density lipoprotein cholesterol by -0.2 mg/dL (95% CI, -0.9 to 0.5 mg/dL) in the high-cereal fiber diet (P = .005). The reduction in dietary glycemic index related positively to the reduction in HbA(1c) concentration (r = 0.35, P < .001) and negatively to the increase in high-density lipoprotein cholesterol (r = -0.19, P = .009).
  
  
  CONCLUSIONS
  In patients with type 2 diabetes, 6-month treatment with a low-glycemic index diet resulted in moderately lower HbA(1c) levels compared with a high-cereal fiber diet. Trial Registration clinicaltrials.gov identifier: NCT00438698.
authors.affiliation: Clinical Nutrition and Risk Factor Modification Center, St Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: David J A
authors.initials: DJ
authors.lastname: Jenkins
authors.forename: Cyril W C
authors.initials: CW
authors.lastname: Kendall
authors.forename: Gail
authors.initials: G
authors.lastname: McKeown-Eyssen
authors.forename: Robert G
authors.initials: RG
authors.lastname: Josse
authors.forename: Jay
authors.initials: J
authors.lastname: Silverberg
authors.forename: Gillian L
authors.initials: GL
authors.lastname: Booth
authors.forename: Edward
authors.initials: E
authors.lastname: Vidgen
authors.forename: Andrea R
authors.initials: AR
authors.lastname: Josse
authors.forename: Tri H
authors.initials: TH
authors.lastname: Nguyen
authors.forename: Sorcha
authors.initials: S
authors.lastname: Corrigan
authors.forename: Monica S
authors.initials: MS
authors.lastname: Banach
authors.forename: Sophie
authors.initials: S
authors.lastname: Ares
authors.forename: Sandy
authors.initials: S
authors.lastname: Mitchell
authors.forename: Azadeh
authors.initials: A
authors.lastname: Emam
authors.forename: Livia S A
authors.initials: LS
authors.lastname: Augustin
authors.forename: Tina L
authors.initials: TL
authors.lastname: Parker
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Leiter
mesh_terms: D000368:Aged; D001786:Blood Glucose; D002318:Cardiovascular Diseases / Q000453:epidemiology; D003131:Combined Modality Therapy; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications / Q000178:diet therapy*; D004040:Dietary Carbohydrates; D004043:Dietary Fiber; D002523:Edible Grain; D005260:Female; D006442:Glycated Hemoglobin; D038321:Glycemic Index; D006801:Humans; D000960:Hypolipidemic Agents / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004043:Dietary Fiber; D006442:Glycated Hemoglobin; D000960:Hypolipidemic Agents