Posted on behalf of Katrina Charles, BA Media Fellow

Another popular press release to help us through August.

Today it is being widely reported (BBC, CBS, CTV) that fruit juices, including grapefruit, orange and apple, can reduce the effectiveness of medication, potentially wiping out the beneficial effects.

The “new evidence” is attributed to a presentation by David Bailey from the University of Western Ontario at the American Chemical Society conference in Philadelphia, although even the abstract indicates that this was a review presentation.

The press release says, which is paraphrased in the papers (Mirror, Times), “the volunteers consumed the drug with either a single glass of grapefruit juice, water containing only naringin (substance in grapefruit juice that gives the juice its bitter taste), or water. When fexofenadine was taken with grapefruit juice, only half of the drug was absorbed compared to taking the drug with water alone, Bailey says.”

So what happened when they drank water containing only naringin? Well according to the paper they published on it last year in Clinical Pharmacology & Therapeutics (a Nature journal), the naringin solution resulted in a 55% reduction of bioavailability of the drug compared to water, grapefruit juice resulted in a 75% reduction.

The researchers first reported interactions between grapefruit juice and medications in 1991 with the finding that it was increasing absorption of the high-blood-pressure drug felodipine. “Since then, other researchers have identified nearly 50 medications that carry the risk of grapefruit-induced drug-overdose interactions” says the press release.

As for the results for the other juices, David Bailey has a myriad of publications on the topic listed on PubMed which do include at least one paper looking at different fruits.

Image: Getty