The study compared the content of certain beneficial compounds in different parts of wild bilberry and blueberry plants. Stems of wild bilberries had the highest amount of a substance that helps with diabetes, much more than the leaves of the same plant or blueberry leaves. This substance was found to be up to 100 times more in wild bilberry stems compared to its leaves, and at least 1000 times more than blueberry leaves. The variation in content was also influenced by the season and location where the plants were grown. The researchers suggest using wild bilberry stems for future studies on treating diabetes.