Doctors have warned patients about drug interactions with grapefruit juice for years.
But it turns out the drink might actually interact with certain drugs in a good way reducing dosages and, therefore, costs and side effects.
U-S researchers wanted to test the drug sirolimus on cancer patients, but they knew only small amounts of the drug, 14 per cent is absorbed into the bloodstream.
So they gave some patients grapefruit juice to get more of the drug into their bodies.
It worked, increasing sirolimus levels by 350 per cent and lowering the necessary doses from 90 milligrams a week to between 25 and 35 milligrams a week.