Riceberry rice (Oryza sativa L.) slows gastric emptying and improves the postprandial glycaemic response

Abstract

Postprandial glycemia is a key determinant of overall glycemic control. One mechanism by which dietary strategies can reduce postprandial glycemic excursions is by slowing gastric emptying. This study aimed to evaluate the acute effect of ingesting riceberry rice (RR) compared to that of ingesting white rice (WR) on gastric emptying rate (GER), plasma glucose, and glucose-regulating hormones, including insulin, glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide 1 (GLP-1), in healthy subjects. A randomized, open-label, within-subject, crossover study was performed in 6 healthy men. GER was measured by scintigraphy over 240 minutes, and plasma concentrations of glucose, insulin, GLP-1 and GIP were measured at multiple time points over 180 minutes. This study revealed that RR slows GER with a reduction in postprandial plasma glucose concentrations compared to WR. Plasma insulin and GLP-1 concentrations did not differ between RR and WR. However, plasma GIP concentrations were markedly increased after WR ingesting versus after RR ingestion. We conclude that RR attenuates postprandial glycemia by slowing GER without altering plasma insulin or GLP-1. Plasma GIP concentrations are likely related to differences in GER and carbohydrate absorption. We propose that dietary fiber-enriched foods, including RR, could contribute to improvement in postprandial glycemia via delayed gastric emptying.

Dietary impact on fasting and stimulated GLP-1 secretion in different metabolic conditions – a narrative review

“…Among other things, meal composition could also influence the results of MMTT or challenge meal studies. In this review, 14 intervention studies compared GLP-1 responses to different liquid or solid tests and challenge meals or foods; see Table 3 [ [59] , [60] , [61] , [62] , [63] , [64] , [65] , [66] , [67] , [68] , [69] , [70] , [71] ] and Supplemental Table 4 . Although for most studies no information on meal duration was provided, the meal durations in the remaining studies were 10–20 min.…”

“…): MED: Mediterranean diet (665 kcal, 32% CH, 45% F, 23% P) HVF: High-fiber Vegetarian diet (704 kcal, 78% CH, 8% F, 15% P) T2DM (BMI:: 34.4 kg/m 2 ) MED 13 18 17 17 17 15 30 5 210 min: AUC: 11359 (pg/mL∗min) # - ↑ AUC in MED compared with HFV ↔ iAUC (trend for ↑ in MED) HFV 12 16 14 15 13 13 30 4 210 min: AUC: 9576 (pg/mL∗min) # Muangchan et al. 2021 [ 62 ] n = 6 RCT cross-over ELISA (Millipore) 2 Test meal (n.a. ): 100 g steamed rice with microwaved labeled egg + water IG: Riceberry rice (370 kcal, 75.5 g CH, 3.6 g F, 8.6 g P, 4.1 g fiber) CG: white rice (350 kcal, 79.4 g CH, 1.2 g F, 5.7 g P, 1.7 g fiber) NW (BMI:: 21.5 kg/m 2 ) IG 38 39 37 35 43 21 120 5 180 min: iAUC: 7094 (pmol/L∗min) - ↔ iAUC - trend for ↑ values in IG after 30 and 60 min CG 32 31 28 27 33 38 180 6 180 min: iAUC: 5687 (pmol/L∗min) Dicks et al.…”

“…Across all the studies and participants, the maximum postprandial GLP-1 concentrations were reached between 15 [ 59 ] and 180 [ [60] , [61] , [62] ] min after the ingestion of the test meal.…”

“…Another study examining the effect of Scottish oats compared with that of isoenergetic pearl millet porridge on the postprandial GLP-1 response in healthy NW adults showed no differences between the 2 test meals [ 66 ]. In addition, a comparison of two test meals with either white rice or riceberry rice (rich in antioxidant bioactive compounds and high in protein and fiber) in 6 healthy men did not reveal significant differences in postprandial GLP-1 secretion, whereas there was a slight trend for higher values after consuming riceberry rice [ 62 ]. Moreover, in 17 participants with T2DM, a test meal with a newly developed rice variety rich in resistant starch (OIST rice) did not lead to higher GLP-1 AUC or iAUC values than a control meal of regular white rice [ 67 ].…”

Changes in content of bioactive constituents and antioxidant activity of riceberry after food processing and degradation kinetics during storage

“…According to a recent study, the riceberry consumption was linked to a longer stomach discharge, which resulted in a reduction in postprandial plasma glucose and a lower risk of diabetes (Muangchan et al, 2021). Furthermore, riceberry phenolic extract has been used to improve mechanical properties of intelligent pH-sensing films for monitoring shrimp freshness (Eze et al, 2022).…”