Description

Blackberries are a rich source of anthocyanins and fiber and their consumption has been proven within multiple studies to have various health benefits. However, most blackberry studies used blackberry juice, powder, or extract in preclinical models. The purpose of this study was to assess if fresh blackberry consumption would improve postprandial blood glucose, satiety, and anxiety responses, as well as if a topical blackberry application would improve skin health. This experimental study consisted of two trials where participants (n=48, 37 females and 11 males; 24.0 ± 4.5 years; BMI 23.1 ± 4.13 kg/m2) consumed either white bread (isocaloric control, 110 kcal) or white bread and blackberries in a crossover design. Satiety and anxiety measures were assessed at baseline, right after consumption, and every 15 or 30 minutes respectively until 90 minutes post consumption. Blood glucose was measured at 0, 30, 60 and 90 minutes post juice consumption. For the topical application, blackberry juice or a sugar solution (control) was applied on the forehead of each participant and skin hydration and oil tests were taken over time. Satiety increased after snack consumption in both trials (P < 0.001), however there were no significant differences between trials. Both trials had increased blood glucose levels at 30 minute post consumption which slowly decreased as the study progressed (P < 0.01). No significant differences were found on postprandial glucose responses between the two trials. Both trials showed reduced anxiety scores over time (P < 0.05) with no significant differences between trials. There was no significant effect of the topical blackberry juice application on skin hydration compared to the sugar solution. Consumption of blackberries with a high glycemic index food (white bread) did not show any significant differences on a postprandial glucose, satiety, or anxiety response when compared to the isocaloric bread trial. There was also no significant effect of blackberry juice on skin health as compared to the sugar solution. Potential future research could include a higher dose of blackberries with a longer time period to monitor blood glucose, satiety, anxiety, and skin hydration over time.