why can't you hold grapefruit products while taking xanax?

The prescription note on a bottle of xanax indicates that you should avoid grapefruit products wihile taking the medicationwhy can't you hold grapefruit products while taking xanax?
Some raw products (such as flavonoids, furanocoumarins) in grapefruit inhibit the liver metabolizing enzyme (cytochrome P450) and subsequently disappear the metabolism of Xanax (which also metabolized by exactly the same cytochrome P450). Thus, the concentration of Xanax contained by blood may increase and exceed the normal extent. Finally, undesired effect may occur.
some meds enjoy this restriction because too much grapefruit can make the drug more potent and harder on the liver. A little doesn't hurt, like 1/2 cup but not with the meds, at a subsequently time. If u don't really like grapefruit purely don't take it.