Hypoglycemic effects of antioxidant-rich plant extracts on postprandial glycemic responses in participants with prediabetes (GLARE study)

Simple item page
dc.citation.issue11
dc.citation.volume11
dc.contributor.authorLim WXJ
dc.contributor.authorGammon CS
dc.contributor.authorVon Hurst PR
dc.contributor.authorChepulis L
dc.contributor.authorMugridge O
dc.contributor.authorPage RA
dc.date.accessioned2023-06-21T22:40:38Z
dc.date.available2021-11-15
dc.date.available2023-06-21T22:40:38Z
dc.date.issued2021-11-15
dc.description©FFC 2021
dc.description.abstractBackground: Plant extracts may help to improve glycemic control in individuals with poor glycemic control. However, few studies have been investigated in the prediabetes cohort, which is a high-risk condition for T2DM. Thus, this study aimed to investigate the acute effect of grape seed, rooibos tea, and olive leaf extracts on postprandial blood glucose and insulin in participants with prediabetes. Methods: An acute, single-blind, placebo-controlled, non-randomized, crossover study (ACTRN12617000837325) where placebo and extracts of grape seed, rooibos tea and olive leaf standardized for total antioxidant capacity were given separately during an oral glucose tolerance test to participants (n=19, five men and fourteen women, aged 65.0 ± 1.6 years, Body Mass Index (BMI) 27.3 ± 1.1 kg/m2) with prediabetes (Glycated hemoglobin A1c (HbA1c) 42 ± 1 mmol/mol). The primary outcome incremental area under the curve of glucose (iAUCglucose) was examined with other glycemic measures. Data was analyzed using linear mixed model for repeated measures. Secondary analysis was conducted by stratifying participants into either a healthier or less healthy subgroup based on the postprandial time to glucose and insulin peaks, with the less healthy subgroup experiencing delayed glucose and/or insulin peaks. Results: There were no overall significant changes to glucose and insulin measures between all plant extracts and placebo (p>0.05). Upon secondary analysis, all extracts affected glycemic responses in the less healthy subgroup. Compared to placebo, grape seed reduced plasma iAUCglucose (p=0.016, 21.9% reduction), 2 h postprandial glucose (2hPG) (p=0.034, 14.7% reduction) and metabolic clearance rate of glucose (MCRglucose) (p=0.016, 16.7% increase). It also improved insulin indices such as 2 h postprandial insulin (2hPI) (p=0.029, 22.4% reduction) and Stumvoll overall insulin sensitivity index (ISIoverall) (p=0.028, 15.0% increase). Rooibos tea extract significantly improved β-cell function as demonstrated by the increased oral disposition index (DI) (p=0.031, 32.4% increase) compared to placebo. Olive leaf extract significantly increased incremental area under the curve of insulin (iAUCinsulin) (p=0.040, 16.7% increase). Conclusion: Grape seed, rooibos tea and olive leaf extracts demonstrated acute hypoglycemic benefits in adults with prediabetes and having less healthy metabolic profiles. A chronic study on the plant extracts is warranted to determine their longer-term impact on prediabetes. Trial Registration ID: ACTRN12617000837325
dc.description.confidentialfalse
dc.edition.editionNovember 2021
dc.format.extent604 - 626
dc.identifierhttps://ffhdj.com/index.php/ffhd/article/view/829
dc.identifier.citationFunctional Foods in Health and Disease, 2021, November 2021, 11 (11), pp. 604 - 626
dc.identifier.doi10.31989/FFHD.V11I11.829
dc.identifier.eissn2160-3855
dc.identifier.elements-id450071
dc.identifier.harvestedMassey_Dark
dc.identifier.issn2378-7007
dc.languageEnglish
dc.publisherFood Science Publisher on behalf of the Academic Society for Functional Foods and Bioactive Compounds (ASFFBC)
dc.publisher.urihttps://ffhdj.com/index.php/ffhd/article/view/829
dc.relation.isPartOfFunctional Foods in Health and Disease
dc.rightsCC BY 4.0
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/
dc.subjectgrape seed extract
dc.subjectrooibos tea extract
dc.subjectolive leaf extract
dc.subjectimpaired glycemic control
dc.subjecthyperglycemia
dc.subjecthypoglycemic effects
dc.subjectinsulin sensitivity
dc.subjectbeta-cell function
dc.titleHypoglycemic effects of antioxidant-rich plant extracts on postprandial glycemic responses in participants with prediabetes (GLARE study)
dc.typeJournal article
pubs.notesNot known
pubs.organisational-group/Massey University
pubs.organisational-group/Massey University/College of Health
pubs.organisational-group/Massey University/College of Health/PVC's Office - College of Health
pubs.organisational-group/Massey University/College of Health/School of Health Science
pubs.organisational-group/Massey University/College of Health/School of Sport, Exercise and Nutrition
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
450071 PDF.pdf
Size:
860.48 KB
Format:
Adobe Portable Document Format
Description:
Download
Collections
Journal Articles