Grapefruit and Diabetic Medication

Grapefruit and some other citric fruits contains a compound called Naringen. This compound focuses on the same enzyme that some blood sugar lowering medication focus on. 

Some research suggests that grapefruit can actually help glycemic control, but if taken when on medication such as metformin, it can create an additive effect, which may cause your blood sugars to drop too low. 

The compounds in grapefruit can restrict the absorption of certain medication like metformin, causing a toxic build up on the liver, resulting in an increase in its effectiveness, which can cause blood sugars dropping too low, and increasing the risk of hypoglycaemia.