Blueberry fruit is likely safe for most people when consumed in food amounts. There is not enough reliable information about the safety of taking blueberry leaf by mouth. It is best to avoid taking leaves.
Special Precautions & Warnings:
Pregnancy and breast-feeding: Blueberry fruit is likely safe when used in amounts commonly found in foods. But not enough is known about the safety of the larger amounts used for medicine. Stick to normal food amounts if you are pregnant or breast-feeding.
Diabetes: Blueberry might lower blood sugar levels in people with diabetes. Watch for signs of low blood sugar (hypoglycemia) and monitor your blood sugar carefully if you have diabetes and use blueberry products. The dose of your diabetes medications may need to be adjusted by your healthcare provider.
Surgery: Blueberry might affect blood glucose levels and could interfere with blood sugar control during and after surgery. Stop using blueberry at least 2 weeks prior to a scheduled surgery.