Grapefruit and Drugs: A Conversation

Ernie NeffGrapefruit

UF 914 pummelo-grapefruit hybrid

University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) citrus breeder Fred Gmitter recently had an email conversation with a retired Swedish pediatrician about a UF/IFAS grapefruit and pummelo hybrid that likely won’t interact with drugs.

The retired physician, Leif Gothefors, had inquired about Gmitter’s work on the hybrid, UF 914. Gothefors noted that he had heard UF 914 had “good values of taste and nutrition (and) also seemed to have the advantage of having low content of furanocoumarins responsible for the effect on a number of drugs.” He stated that he and his wife have been prescribed drugs with the warning, “avoid grapefruit.” Gothefors added, “We for many years had a mix of orange and grapefruit juice for breakfast, so this was annoying.”

Gmitter responded that UF 914 “produces fruit with excellent quality, beautiful color, flavor and aroma very similar to grapefruit, but usually perceived as sweeter by consumers. And yes, extremely low to undetectable levels of the major bioactive furanocoumarin (FC) compounds. We tested the fruit and juice chemically to measure FC levels. We tested it with human cell cultures to confirm its lack of interaction with drugs; and finally we performed a pilot human subject trial. But to claim that it is safe would require a much larger clinical trial that would cost a lot of money. To date, no one has come forth with funding to support such a trial.” 

“No growers in Florida have planted 914 because of HLB,” Gmitter added. “914 may be a bit more tolerant of the disease than common grapefruit, but not enough for growers to have confidence in it.”

Gmitter pointed out that UF/IFAS researcher Arnold Schumann at the Citrus Research and Education Center has successfully grown 914 in an enclosed screen structure with very good results.  But so far, there is no commercial production in Florida. “UF 914 has caught the attention of citrus growers outside the U.S., and perhaps it may become a commercial product there, before it does so in Florida,” he said.

Gmitter had more thoughts about UF 914 in addition to his exchange with Gothefors. “My emphasis is on the excellent eating quality,” he said. “We tested UF 914 with consumer focus groups several years ago. The groups were divided into grapefruit lovers and haters. The ‘haters’ said that if grapefruit always tasted like this, then they would buy it and eat it. The ‘lovers’ stated things like, ‘The best grapefruit I have ever tasted’ and ‘If I could buy this, I wouldn’t need to put sugar on my morning grapefruit.’”

Learn more about UF 914 and other Florida citrus varieties.

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About the Author

Ernie Neff

Senior Correspondent at Large