Raspberry Leaf Tea‘s Impact on Insulin Response to Sucrose: Aโฃ New Study
A recent study published in โฃ Nutrients (2025) by Alkhudaydi and Spencer investigated the effects โขof raspberry leaf tea on postprandial glucose andโฃ insulin responsesโ in healthy adults. The research revealedโ a significant reduction in insulin surges following โthe consumption of sucroseโค (table sugar) when paired wiht raspberry leafโ tea, but no such effect was observed with glucose alone.
The trialโฃ involved 22 participants, โ20 of whom completed all study visits.Participants consumed either sucrose or glucose, with or without concurrentโข consumption โof raspberry leaf teaโข brewed for five minutes – a readiness standardized to deliver โapproximately 50 mg of totalโค polyphenols, primarily ellagitannins and ellagic acid, โคper serving. blood samples were โคcollected at baseline and at 15, 30, 60, 90, and 120-minute intervals post-consumption, with glucose analyzed using the hexokinase โmethod and insulin via automated immunoassay.
Results demonstrated that when sucrose was consumed, raspberry leaf tea substantially lowered both glucose and insulin responses. Specifically, mean โขglucose levels decreased by 1.19 mmol/L โat 15 minutes (p = 0.001) and 2.03 mmol/L at 30 minutes (p = 0.0004). Insulinโฃ levels were suppressed by 113.9 pmol/L at โข15 minutes (pโข = 0.019),โ 161.8 pmol/L at 30 minutes (pโข = 0.0008), and 139.4 pmol/L at 60 โminutes (p โค= 0.025).
Notably,no statistically significantโ differences in โคblood glucose or insulin were found between the tea and control conditions when participants โconsumed glucose. Both glucose and insulin peaked at 30 minutes and returned to baseline levels by 120 minutes, nonetheless of tea intake.This finding indicates the beneficial effects of raspberry leaf tea are specific โขto โขdisaccharide metabolism – the breakdown of sugars like sucrose -โข rather than monosaccharide absorption (like glucose).
The researchers hypothesize that the tea’s effect stems from its inhibition of carbohydrate-digesting enzymes, such as ฮฑ-glucosidase and sucrase, likely due โขto the presence of ellagic acid and other polyphenols. Importantly, participantsโค did not report any gastrointestinal side effects, suggesting raspberry leaf tea โcould be a well-tolerated โdietary approach to managing glycemic responses.
The study acknowledges several limitations, including its acute design (single-dose), lack of blinding and placebo control, small and homogeneousโ sample size, and short duration. These โfactors limit the generalizability of the โfindings and preclude conclusions regarding long-term effects. The authors recommend larger, longer-term โstudies in more diverse populations, including individuals with impaired glucose โฃcontrol, to further investigate the potential of raspberry leaf tea as a natural modulator of postprandial glycemia.