Grapefruit is off limits to patients who take many prescription medications, but a new hybrid may allow them to indulge with no fear of negative grapefruit drug interactions.
A new hybrid grapefruit developed in Florida has very low levels of furanocoumarins, a family of natural chemical compounds that cause the "grapefruit juice effect."
Over 85 prescription medications are known to interact with grapefruit, and 43 of them have serious side effects when taken with grapefruit. With certain medications that are especially sensitive to grapefruit drug interactions, furanocoumarins can cause kidney or respiratory failure, gastrointestinal bleeding, and even sudden death.
Fred Gmitter, a University of Florida citrus researcher, says that his new hybrid grapefruit, called UF914 for now, has furanocoumarin levels that are much lower than the levels in standard grapefruit.
Tests of the UF914 grapefruit juice in human cell cultures suggest that the fruit will not produce harmful side effects, though human clinical trials will still be necessary to prove that the hybrid cannot cause grapefruit drug interactions.
The University of Florida is working on commercializing the UF914 hybrid, which is a cross between red grapefruit and pomelo. It probably take five to seven years until the hybrid can be produced on a large-scale commercial level.
"I've gotten phone calls from all around the country ... saying, oh my gosh, I miss my Florida grapefruit, when can I have this grapefruit, I miss grapefruit so much," said Gmitter to Reuters.
According to Gmitter, his lab was working on creating a sweeter and less bitter grapefruit hybrid, and only incidentally discovered that UF914 had lower furanocoumarin levels. The hybrid, which is seedless, larger, juicier, sweeter, and less bitter than a standard grapefruit, has already gained the approval of focus groups.
Furanocoumarins inhibit enzymes that break down certain medications, which allows the drugs to enter the bloodstream in much higher concentrations than they are supposed to, leading to overdose.
Common cholesterol-lowering statins, new anticancer drugs, heart drugs, synthetic opiates and psychiatric drugs, and some birth control pills can have grapefruit drug interactions. The full list of prescription medications that interact with grapefruit is available from the Canadian Medical Association Journal.
Until the new grapefruit hybrid comes to market, you can follow this advice from the New York Times about grapefruit drug interactions:
- If you take oral medication of any kind, check the list to see if it interacts with grapefruit. Make sure you understand the potential side effects of an interaction; if they are life-threatening or could cause permanent injury, avoid grapefruit altogether. Some drugs, such as clopidogrel, may be less effective when taken with grapefruit.
- If you take one of the listed drugs a regular basis, keep in mind that you may want to avoid grapefruit, as well as pomelo, lime and marmalade. Be on the lookout for symptoms that could be side effects of the drug. If you are on statins, this could be unusual muscle soreness.
- It is not enough to avoid taking your medicine at the same time as grapefruit. You must avoid consuming grapefruit the whole period that you are on the medication.
- In general, it is a good idea to avoid sudden dramatic changes in diet and extreme diets that rely on a narrow group of foods. If you can't live without grapefruit, ask your doctor if there's an alternative drug for you.