There are food components with the capacity to delay or even inhibit the development of obesity and type 2 diabetes. One hypothesis is that food components rich in polyphenols exert anti-diabetic effects. Polyphenols are natural compounds providing taste and color to plants, including fruits, berries, vegetables, cereals, tea, coffee and wine. However, so far very little is known about the cellular and molecular mechanisms underlying the beneficial effects of polyphenols and their role in prevention of obesity and type 2 diabetes.
Our hypothesis is that polyphenols are metabolized by the intestinal microflora to form more bioactive compounds that influence host health in different ways, e.g. gene regulation. In addition, polyphenols are suggested to modify the gut microbial composition and activity and to increase the diversity of the microflora. Elucidating the mechanisms behind polyphenol metabolism is an important step in the understanding of their health effects.
Screening of metabolic effects of polyphenol-rich berries in high fat-fed C57BL/6J mice
Eight different polyphenol-rich berries were supplemented to high fat diet. The test diets were compared to a high-fat control and a low-fat control diet. Mice fed the diet supplemented with lingonberries gained 20% less weight compared to high-fat control. Lingonberries, bilberries and blackcurrants all showed reduced liver fat accumulation while the opposite was seen for the group receiving açai where development of fatty livers indicated liver steatosis. The lingonberry diet had, overall, very beneficial effects and the negative metabolic changes induced by the high fat diet were almost completely inhibited regarding glucose, insulin and cholesterol in plasma. In addition, the inflammatory marker PAI-1 was significantly reduced in the lingonberry group compared to control, indicating a reduced systemic inflammation as a response of lingonberry (Lovisa Heyman et al. Evaluation of Beneficial Metabolic Effects of Berries in High-Fat Fed C57BL6/J mice, J Nutr Metab 2014, doi: 10.1155/2014/403041).
Principal investigator: Dr Karin Berger
PhD student: Lovisa Heyman MSc