Plain language summary
Elevated levels of blood glucose after eating, known as postprandial hyperglycaemia, contribute to the development of cardiovascular disease and type 2 diabetes. Postprandial hyperglycaemia is a condition that can be improved through lifestyle and diet modifications. The aim of the study was to investigate and compare the postprandial glycaemic and insulin responses after consuming five different probiotic fruit or vegetable beverages. A secondary aim was to analyse beverages for their polyphenol content and antioxidative capacity. The study is a randomised, controlled, crossover study which included twelve healthy young adults (6 men and 6 women) with a BMI of 24.3 +/- 2.4kg/m2. Results indicate that Bilberry showed the most profound insulin lowering effect, followed by Rose hip. The analysis also showed that Bilberry had the highest values of the total phenolic compounds and flavonols, whereas Mango had the lowest. The highest values of antioxidative capacity were found in Bilberry and Beetroot. Authors conclude that consumption of food products that induce a lower insulin response may enhance insulin sensitivity.
Abstract
BACKGROUND Consumption of polyphenol-rich fruits and vegetables may improve postprandial glucose and insulin levels and hence promote well-being. Previously it has been observed that consumption of bilberry decreases the postprandial insulin demand. The intention with the present study was to compare the impact of different supplements with various polyphenol profiles, on the postprandial glucose and insulin responses in healthy young adults. METHODS In a randomized, controlled, crossover study the postprandial glycemic and insulin responses were observed in eleven healthy adults after intake of five different beverages containing bilberry (European blueberry), blackcurrant, beetroot, mango and rose hip, respectively; all drinks were enriched with the same composition of fermented oatmeal and probiotics. The control was a glucose drink. The profile and content of the polyphenols in the different beverages were determined by HPLC-DAD analysis. The antioxidative capacity of the different beverages were measured by TEAC and DPPH assays. RESULTS Beverages containing bilberry, blackcurrant, mango or rose hip significantly attenuated the early postprandial insulin response (0-90 min), but showed no effect on glucose response. Drinks with bilberry or rose hip reduced the insulin response from the very early phase (0-30 min), and had significantly lower insulin index compared with the control. The efficiency of the bilberry and rose hip to decrease early postprandial insulin responses correlated with higher phenolic contents. CONCLUSIONS Supplements with bilberry, blackcurrant, mango or rose hip in the tested probiotic and oatmeal enriched beverage attenuated early-phase insulin response, but had no effect on the postprandial glycemic response. The improved ability of bilberry and rose hip to lower the very early phase of insulin response seems to be due to a higher phenolic content. TRIAL REGISTRATION The study was retrospectively registered at ClinicalTrials.gov with number NCT03159065 .
Methodological quality
Allocation concealment
:
Yes
