Q: Does papaya have a blood-thinning effect?

I understand the concern with foods containing vitamin K, but what about foods that may have a blood thinning effect? For example: I ate a large amount of red papaya when we were in Costa Rica a few years ago. When I returned home and had a protime test, my INR was extremely high. I was told it was because of the papaya. Is it OK to eat it occasionally but not everyday as I did there? Are there other foods that have a blood thinning effect?

A: Dr. Gourmet Says...

There are about 3 micrograms of Vitamin K in 4 ounces of papaya. It may be that by eating a great deal of papaya you consumed too much Vitamin K and that is what caused an elevation of your INR.

There has been one case report in the literature that indicates a possible reaction between papain and Coumadin (warfarin). Papain is an enzyme found in papayas that has digestive properties in humans. This could be a potential cause of the change in your INR levels. I have found no other evidence to support an interaction between the fruit itself and Coumadin, however.

Since you did have an issue a good approach would be to speak with your doctor and discuss your trying to introduce papaya into your diet a few days before your labs are drawn and see if there is any variation.

Thanks for writing,

Eat well, eat healthy, enjoy life!

Timothy S. Harlan, M.D.
Dr. Gourmet