Study shows positive effect of red fruit juices on fat metabolism

From 2018 to 2022, the research team led by Prof. Dr. Elke Richling and Prof. Dr. Peter Winterhalter examined extracts of 20 different fruit juices and concentrates from nine fruit varieties in an in vitro model for the effect of the secondary plant constituents on lipid metabolism. "The most potent effect was found in the in vitro model with extracts from chokeberry, cranberry and pomegranate juice concentrate," explains Prof. Dr. Peter Winterhalter of the Technical University of Braunschweig. "Now we have been able to verify these findings with a human study."

In the nine-week human study with 36 male volunteers, the effectiveness of the juices from chokeberry, cranberry and pomegranate was examined in comparison to a placebo drink. After a one-week washout period, half of the subjects consumed 750 ml of the test drink daily for eight weeks (test group) and the other half of the subjects consumed the same amount of the placebo drink (control group).

Among other things, the reduction in calorie and fat intake and a significant increase in lean body mass were observed in the test group as a result of the fruit juice consumption. In contrast, in the control group, which consumed the placebo drink, an increase in body weight and an increase in leptin concentration were observed. Leptin is a hormone produced by fat cells that helps regulate energy balance.

"The human study confirmed our hypothesis from the in vitro study," says Prof. Dr. Elke Richling of the Technical University of Kaiserslautern. "The results obtained in the in vitro model and in humans provide evidence that the red fruits chokeberry, cranberry and pomegranate in particular can intervene in the fat metabolism of humans in a regulating way and influence it positively."

Thus, the project lays an essential foundation for further work in order to move towards the granting of corresponding health claims in the long term.