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Hello all, I'm currently on metformin and I've have heard that grape fruit and metformin is apparently a big 'no no'. I mean it could be deadly. I read that it increases levels of lactic acid in your system. I don't know much about lactic acid but I know too much of it is not good for you. Is there any truth to the grape fruit situation. I like to have a half of grapefruit with my breakfast. I believe it helps me manage my sugar levels and gets my day off to a good start. Anyone know the scoop on the poop? Thanks.



Hi, There has been one study that I'm aware of on grapefruit juice and lactic acid levels in rats. In this study, non-diabetic rats were given high doses of metformin which produced higher levels of lactic acid in blood. Rats not treated with metformin had lower lactic acid levels. Then, rats were treated with metformin and grapefruit juice and their levels of lactic acid in blood were higher than rats treated with just metformin. The rats given metfromin and grapefruit juice also had higher levels of metformin in the liver. Additionally, researchers also found that grapefruit juice lowered fasting sugar levels. These researchers concluded that “Although GFJ may be beneficial to diabetic patients, it may exacerbate lactic acidosis in diabetic patients taking metformin concurrently”. Well, this is just one small study and it was done on rats so there is nothing conclusive. Based on this study, I wouldn't stop eating grapefruit after all it does say it lowered fasting sugar levels. I can't imagine that eating a half a grapefruit at breakfast could do any harm. The experiment on rats used grapefruit juice anyway and probably a lot of it which is a far cry from whole grapefruit. Unless the grapefruit is causing stomach upset, heartburn or diarrhea, I don't see any reason not to enjoy.