Supplements · Diets · Metabolic & Cardiometabolic
Does inulin fibre lower fasting blood sugar?
The claim, precisely: inulin-type fructans decreases fasting glucose
Strong support Supplements
RefutedContestedStrong support
consensus score 1.00
Yes, modestly, but only in people who already have type 2 diabetes, not in healthy people.
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: All trials, pooled (Meta-analysis)
MechanismIn-vitroAnimalObservationalRCTMeta-analysis
How the studies fall
3 support 0 contradict 0 tested null 0 mixed · 3 sources, 3 independent groups
What the evidence shows
Inulin-type fructans lower fasting glucose (-0.42 mmol/L) only in people with T2D; effect is null in healthy/overweight-only groups — a conditional, not general, glucose claim.
The evidence (3)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| inulin-t2d-2019 2019 | meta-analysis | supports | high | GRADE dose-response MA of 33 RCTs: inulin-type fructans improve glycemic control incl fasting glucose in prediabetes/T2D |
| Li L, et al. 2021 · Food Sci Nutr | meta-analysis | supports | moderate | FBG WMD -0.42 mmol/L in diabetics; no effect in healthy/overweight strata |
| Dehghan 2014 · Nutrition | RCT | supports | moderate | Oligofructose-enriched inulin 10g/d x8wk cut fasting glucose 9.5% vs maltodextrin in women with T2D |
Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.