Dietary Fibre and Organic Acids in Kiwifruit Suppress Glycaemic Response Equally by Delaying Absorption-A Randomised Crossover Human Trial with Parallel Analysis of 13 C-Acetate Uptake.
Level 2 - randomized trial
Individual randomized crossover trial
PubMed 35956366 · doi:10.3390/nu14153189
What was done
Nine healthy participants consumed five equal-carbohydrate test meals in a randomized crossover design: wheat biscuit with sugars equivalent to two kiwifruits (WB+KFsug, control), wheat biscuit plus whole kiwifruit pulp (WB+KF), wheat biscuit plus neutralized kiwifruit pulp (WB+KFneut), wheat biscuit plus low-fiber kiwifruit juice (WB+KFjuice), and WB+KFsug plus kiwifruit organic acids (WB+KFsug+OA). All meals were spiked with 100 mg sodium [1-13C] acetate to monitor intestinal absorption. Blood glucose and breath 13CO2 were measured at baseline and every 15 minutes up to 180 minutes.
What was found
Compared with WB+KFsug, whole kiwifruit pulp (WB+KF) almost halved glycemic response amplitude (p < 0.001), reduced incremental area under the blood glucose curve (iAUC) at 30 minutes by 50% (p < 0.001), and averted late postprandial hypoglycemia. All other treatments suppressed amplitude half as much as whole kiwifruit and averted acute hypoglycemia, with little effect on iAUC. Effects on 13CO2 exhalation paralleled blood glucose responses (R2 = 0.97), indicating that dietary fiber and organic acids contributed equally to the anti-glycemic effect by slowing absorption.
Why it matters
This study shows that the glycemic-lowering effect of kiwifruit co-consumed with starch is driven equally by organic acids and dietary fiber delaying carbohydrate absorption. It supports substituting whole fruit for refined carbohydrates to moderate postprandial glycemia.
Limits
The sample size was very small (n = 9) and restricted to healthy participants, limiting generalizability to populations with impaired glucose tolerance or diabetes. The trial assessed only acute single-meal responses rather than chronic metabolic outcomes.
Cited by
- supports Dietary fiber slows glucose absorption, flattens blood sugar spikes, and feeds gut bacteria that reduce systemic inflammation.