Effect of fructose on glycemic control in diabetes: a systematic review and meta-analysis of controlled feeding trials.
OBJECTIVE
The effect of fructose on cardiometabolic risk in humans is controversial. We conducted a systematic review and meta-analysis of controlled feeding trials to clarify the effect of fructose on glycemic control in individuals with diabetes.


METHODS
We searched MEDLINE, EMBASE, and the Cochrane Library (through 22 March 2012) for relevant trials lasting ≥7 days. Data were aggregated by the generic inverse variance method (random-effects models) and expressed as mean difference (MD) for fasting glucose and insulin and standardized MD (SMD) with 95% CI for glycated hemoglobin (HbA(1c)) and glycated albumin. Heterogeneity was assessed by the Cochran Q statistic and quantified by the I(2) statistic. Trial quality was assessed by the Heyland methodological quality score (MQS).


RESULTS
Eighteen trials (n = 209) met the eligibility criteria. Isocaloric exchange of fructose for carbohydrate reduced glycated blood proteins (SMD -0.25 [95% CI -0.46 to -0.04]; P = 0.02) with significant intertrial heterogeneity (I(2) = 63%; P = 0.001). This reduction is equivalent to a ~0.53% reduction in HbA(1c). Fructose consumption did not significantly affect fasting glucose or insulin. A priori subgroup analyses showed no evidence of effect modification on any end point.


CONCLUSIONS
Isocaloric exchange of fructose for other carbohydrate improves long-term glycemic control, as assessed by glycated blood proteins, without affecting insulin in people with diabetes. Generalizability may be limited because most of the trials were <12 weeks and had relatively low MQS (<8). To confirm these findings, larger and longer fructose feeding trials assessing both possible glycemic benefit and adverse metabolic effects are required.
Clinical Nutrition and Risk Factor Modification Center, St. Michael’s Hospital, Toronto, Ontario, Canada.
Adrian I
AI
Cozma
John L
JL
Sievenpiper
Russell J
RJ
de Souza
Laura
L
Chiavaroli
Vanessa
V
Ha
D David
DD
Wang
Arash
A
Mirrahimi
Matt E
ME
Yu
Amanda J
AJ
Carleton
Marco
M
Di Buono
Alexandra L
AL
Jenkins
Lawrence A
LA
Leiter
Thomas M S
TM
Wolever
Joseph
J
Beyene
Cyril W C
CW
Kendall
David J A
DJ
Jenkins
D000328:Adult; D001786:Blood Glucose / Q000187:drug effects* / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D005632:Fructose / Q000627:therapeutic use*; D006442:Glycated Hemoglobin / Q000187:drug effects*; D006801:Humans; D007328:Insulin / Q000097:blood; D008875:Middle Aged
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D005632:Fructose; D006442:Glycated Hemoglobin; D007328:Insulin