Meta-Analyses and Meta-Regression Models of Intervention Studies
Background: The glycemic response to dietary fructose is low, which may improve concentrations of glycated hemoglobin (HbA1c, a marker of dysglycemia). Meanwhile, adverse effects on plasma triacylglycerol (a marker of dyslipidemia) and body weight have been questioned. Such effects are reported inconsistently.
Objective: We aimed to evaluate the effect of fructose on these health markers, particularly examining treatment dose and duration, and level of glycemic control.
Design: A literature search was conducted for relevant randomized and controlled intervention studies of crystalline or pure fructose (excluding high-fructose corn syrup), data extraction, metaanalyses, and modeling using meta-regression.
Results: Fructose intake 90 g/d significantly improved HbA1c concentrations dependent on the dose, the duration of study, and the continuous severity of dysglycemia throughout the range of dysglycemia. There was no significant change in body weight at intakes 100 g fructose/d. Fructose intakes of 50 g/d had no postprandially significant effect on triacylglycerol and those of 100g/d had no significant effect when subjects were fasting. At 100 g fructose/d, the effect on fasting triacylglycerol depended on whether sucrose or starch was being exchanged with fructose, and the effect was dosedependent but was less with increasing duration of treatment. Different health types and sources of bias were examined; they showed no significant departure from a general trend.
Conclusions: The meta-analysis shows that fructose intakes from 0 to 90 g/d have a beneficial effect on HbA1c. Significant effects on postprandial triacylglycerols are not evident unless 50 g fructose/d is consumed, and no significant effects are seen for fasting triacylglycerol or body weight with intakes of 100 g fructose/d in adults. Am J Clin Nutr 2008;88:1419 –37.
For the full length version of this article, click here.