Precautions
In most cases it is safe to eat bilberries. As with many foods, including coffee, tea, red wine, blueberries, cranberries, chocolate, some nuts, and beans, bilberries naturally contain compounds referred to as tannins. You should stay away from bilberry if you are allergic to or sensitive to foods that contain tannins.
Since the safety of bilberry extracts is unknown, pregnant or nursing women should avoid using them. Taking bilberry supplements in excessive amounts or for an extended period of time may not be safe. Bilberry leaf consumption could be harmful if done frequently or in large doses.
If you’re thinking about trying bilberry supplements, have a conversation with your doctor first to discuss the benefits and draw your own conclusions about if it’s right for you.