UF professor available to discuss grapefruit/drug interaction, possible solution

November 30, 2012

GAINESVILLE, Fla. — A University of Florida citrus breeder is available to discuss the phenomenon of grapefruit and grapefruit products interfering with some medications, and a possible solution to the problem.

The topic of grapefruit/drug interactions has been in the news this week, following the publication of a Canadian study that indicates the number of medications subject to these interactions has doubled since 2008.

Fred Gmitter, a professor with UF’s Institute of Food and Agricultural Sciences, is part of a research team developing hybrid fruit varieties that taste and look like grapefruit but contain lower levels of furanocoumarins, the compounds believed to cause the drug interactions by interfering with certain human digestive enzymes.

Gmitter, at UF’s Citrus Research and Education Center in Lake Alfred, is working on the project with UF colleague Chunxian Chen, a research associate in citrus genomics, and with Florida Department of Citrus research scientist Paul Cancalon, also based at the Lake Alfred center.

“We’re working on alternatives to grapefruit that will have dramatically reduced levels of the most interactive of the furanocoumarins,” Gmitter said.

The hybrid fruits are a cross between grapefruit and pummelo, a citrus species native to Southeast Asia.

One hybrid has been approved for release and is expected to be offered for licensing in the near future. It’s known as UF 914 and has extremely low furanocoumarin content. The fruit resembles a large, red-fleshed grapefruit; it’s seedless and has lower acidity than typical grapefruit.

In vitro tests using human cell cultures indicate that UF 914 interfered with digestive enzymes much less than standard grapefruit.

“What is sorely needed is funding to conduct the all-important human clinical trials that would be necessary to make any claims about its safety,” Gmitter said.

Gmitter can be reached at 863-956-8878 or fgmitter@ufl.edu. For more information about him: http://www.crec.ifas.ufl.edu/academics/faculty/gmitter/gmitter_fred_jr.shtml