Randomised controlled trials (RCTs) of the effects of dietary inulin-type fructans (inulin and oligofructose) on serum lipid concentrations were eligible for inclusion. Trials had to have a sequential, parallel or crossover design. Eligible trials also had to specify the type and amount of inulin-type dietary fructans used, and to provide outcome measures of serum triacylglycerol concentrations.
The included trials evaluated oligofructose and inulin of different chain lengths. The average amount of substance, given as sweetener or powder, was 14g daily for oligofructose (range 8g to 20g) and 14.2g daily for inulin (range 4g to 34g). The median duration of the trials was 28 days (range 21 to 64). The patients in the included trials were men and women who were healthy individuals (46%), had hypercholesterolaemia or hypertriglyceridaemia (39%), type II diabetes (9.3%), or non-alcoholic fatty liver disease (2%). In the majority of the trials, the participants were used as their own control.
The author did not specify how the papers were selected for the review, or how many reviewers performed the selection.