Effect of fructose on glycemic control in diabetes: a systematic review and meta-analysis of controlled feeding trials.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of controlled feeding trials
PubMed 22723585 · doi:10.2337/dc12-0073
What was done
Researchers conducted a systematic review and meta-analysis of controlled feeding trials lasting at least 7 days to evaluate the impact of fructose on glycemic control in individuals with diabetes. Databases searched through March 2012 included MEDLINE, EMBASE, and the Cochrane Library. Outcomes included glycated blood proteins (HbA1c and glycated albumin), fasting glucose, and fasting insulin, pooled using random-effects models.
What was found
Across 18 trials including 209 participants, isocaloric substitution of fructose for other carbohydrates significantly reduced glycated blood proteins (SMD -0.25, 95% CI -0.46 to -0.04; P = 0.02), equivalent to an approximate 0.53% reduction in HbA1c. Significant intertrial heterogeneity was present (I² = 63%, P = 0.001). Fructose intake had no significant effect on fasting blood glucose or fasting insulin levels.
Why it matters
These findings suggest that substituting fructose for other dietary carbohydrates does not worsen and may modestly improve medium- to long-term glycemic markers in diabetes patients when calories are held constant.
Limits
The total sample size was small (209 participants across 18 trials). Most included studies were shorter than 12 weeks, had low methodological quality scores (<8 on the Heyland scale), and showed substantial statistical heterogeneity. Adverse metabolic outcomes (such as lipid profiles or uric acid) were not detailed in the abstract.
Cited by
- supports Meta-analyses of randomized trials show that when total energy is equated, sugar intake does not adversely affect inflammatory markers or blood glucose metabolism compared to other carbohydrate sources.