In a study on laboratory hamsters, better cholesterol health was found in hamsters that had blueberry peels and other leftovers from blueberry juice processing added to their rations compared to hamsters without blueberry enhanced rations.
For the study, hamsters were given high-fat rations, and for some hamsters these rations were supplemented with one of 3 different types of blueberry juice by products: fiber extracted from the blueberry peels; blueberry skin peels which are leftover after berries are pressed for juice making; or natural compounds extracted from the blueberry peels called polyphenols. The blueberry’s blue, purple, and red coloration is produced by the polyphenols.
All the hamsters which were given rations enhanced with blueberries had from 22% to 27% reduced total plasma cholesterol compared to hamsters which were given rations that didn’t have blueberry juice by products.
Levels of a type of “bad” cholesterol, very low density lipoprotein (VLDL), were approximately 44% lower in the hamsters that ate blueberry peels.
A procedure called real-time reverse transcription polymerase chain reaction (RT-PCR) was made use of to examine the genes that were responsible for these effects. This process made it possible for the researchers to identify differences in the activity level of specific liver genes.
Both In humans and in hamsters the liver produces cholesterol as well as helps to get rid of excessive levels of cholesterol. The results of the study indicate that the activity of some liver genes which either use or produce cholesterol led to the reduction in blood cholesterol levels.