Grapefruit, orange and apple juices can harm the body's ability to absorb certain medications and make the drugs less effective, said a Canadian study released last week in the United States.

Also, I love to drink large amounts of juices (orange and grapefruit) as well as water.

"Recently, we discovered that grapefruit and these other fruit juices substantially decrease the oral absorption of certain drugs undergoing intestinal uptake transport," AFP quoted Bailey as saying.