Do green leafy vegetables increase the prothrombin time?

Q: I underwent surgery for aortic valve replacement. I am taking Acitrom daily. I was advised not to take green leafy vegetables like cabbage etc. Do these increase or decrease the prothrombin time (PT)? Increase in PT means more thinning of blood.

A:Although not definitely proven, there is a general belief that green leafy vegetables etc. increase the prothrombin time (PT). These items of food are preferably avoided if the PT is fluctuating as happens in some cases. If your PT is stable on a certain dose of Acitrom this precaution is not required.