Abstract
Impaired postprandial glucose handling and low-grade systemic inflammation are risk factors for developing insulin resistance in individuals with overweight or obesity. Acute ingestion of anthocyanins improves postprandial glucose responses to a single carbohydrate-rich meal under strictly controlled conditions.PurposeExamine whether acute and short-term supplementation with anthocyanin-rich New Zealand blackcurrant (NZBC) extract can improve postprandial glucose responses to mixed-macronutrient meals.MethodsTwenty-five overweight (BMI > 25 kg m2) sedentary individuals participated in one of the following double-blinded, randomised controlled trials: (1) ingestion of 600 mg NZBC extract or placebo prior to consumption of a high-carbohydrate, high-fat liquid meal (n = 12); (2) 8-days supplementation with NZBC extract (600 mg day−1) or placebo, with insulin sensitivity and markers of inflammation assessed on day-7, and free-living postprandial glucose (continuous glucose monitoring) assessed on day-8 (n = 13).ResultsA single dose of NZBC extract had no effect on 3 h postprandial glucose, insulin or triglyceride responses. However, in response to short-term NZBC extract supplementation insulin sensitivity was improved (+ 22%; P = 0.011), circulating C-reactive protein concentrations decreased (P = 0.008), and free-living postprandial glucose responses to both breakfast and lunch meals were reduced (− 9% and − 8%, respectively; P < 0.05), compared to placebo.ConclusionThese novel results indicate that repeated intake, rather than a single dose of NZBC extract, is required to induce beneficial effects on insulin sensitivity and postprandial glucose handling in individuals with overweight or obesity. Continuous glucose monitoring enabled an effect of NZBC extract to be observed under free-living conditions and highlights the potential of anthocyanin-rich supplements as a viable strategy to reduce insulin resistance.
Highlights
Recent estimates suggest that nearly two-thirds of adults in the UK are classified as overweight or obese [1]
In response to the carbohydrate-fat test drink, there were main time effects for plasma glucose and insulin concentrations (P = 0.02), neither peak glucose nor insulin concentrations differed between conditions
The key novel observations from the two studies described are: (1) acute ingestion of New Zealand blackcurrant (NZBC) extract did not improve the postprandial glucose, insulin or triglyceride responses to a high-carbohydrate, high-fat meal in individuals with overweight or obesity; and (2) short-term (8 days) supplementation with NZBC extract improved free-living postprandial glucose responses and increased whole-body insulin sensitivity in individuals with overweight or obesity. These findings suggest that repeated intake of anthocyanin-rich NZBC extract is required to induce a beneficial effect on insulin sensitivity and postprandial glucose excursions to ‘real world’ mixed-macronutrient meals
Summary
Recent estimates suggest that nearly two-thirds of adults in the UK are classified as overweight or obese [1]. Individuals who are overweight or obese may exhibit elevated postprandial glucose and triglyceride responses [2], as well as systemic inflammation [3], leading to insulin resistance and an increased risk of type 2 diabetes (T2D) and cardiovascular disease. Emerging evidence has highlighted a potential role for foods and beverages containing flavonoids to reduce T2D risk. In this context, the anthocyanins (a major flavonoid subclass) are of particular interest because prospective studies demonstrate that higher anthocyanin intakes are associated with a lower risk of T2D and cardiovascular disease [4,5,6]. To truly examine whether anthocyanins can reduce T2D risk, it is vital to explore the ability of anthocyanins to modulate free-living
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
