title: Effect of ethnicity on glycaemic index: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Low glycaemic index (GI) foods are recommended to improve glycaemic control in diabetes; however, Health Canada considers that GI food labeling would be misleading and unhelpful, in part, because selected studies suggest that GI values are inaccurate due to an effect of ethnicity. Therefore, we conducted a systematic review and meta-analysis to compare the GI of foods when measured in Caucasians versus non-Caucasians.
  
  
  METHODS
  We searched MEDLINE, EMBASE and Cochrane databases for relevant articles. GI differences were aggregated using the generic inverse variance method (random effects model) and expressed as mean difference (MD) with 95% confidence intervals (95% CI). Study quality was assessed based on how well studies complied with official international GI methodology.
  
  
  RESULTS
  Review of 1288 trials revealed eight eligible studies, including 28 comparisons of GI among 585 non-Caucasians and 971 Caucasians. Overall, there was borderline significant evidence of higher GI in non-Caucasians than Caucasians (MD, 3.3 (95% CI, -0.1, 6.8); P=0.06) with significant heterogeneity (I(2), 46%; P=0.005). The GI of eight types of rice was higher in non-Caucasians than Caucasians (MD, 9.5 (95% CI, 3.7, 23.1); P=0.001), but there was no significant difference for the other 20 foods (MD, 1.0 (95% CI, -2.5, 4.6); P=0.57). MD was significantly greater in the four low-quality studies (nine comparisons) than the four high-quality studies (19 comparisons; 7.8 vs 0.7, P=0.047).
  
  
  CONCLUSIONS
  With the possible exception of rice, existing evidence suggests that GI values do not differ when measured in Caucasians versus non-Caucasians. To confirm these findings high-quality studies using a wide range of foods are required.
authors.affiliation: 1] Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada [2] Keenan Research Centre of the Li Ka Shing Knowledge Institute, St Michael's Hospital, Toronto, Ontario, Canada [3] Department of Medicine, St Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: T M S
authors.initials: TM
authors.lastname: Wolever
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.
authors.forename: J L
authors.initials: JL
authors.lastname: Giddens
authors.affiliation: 1] Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada [2] Department of Medicine, St Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: J L
authors.initials: JL
authors.lastname: Sievenpiper