In addition, he said, investigators can now study other fruits containing DHB to see whether they affect the body's uptake of drugs. When the investigators had 10 healthy volunteers chase a dose of felodipine with either grapefruit juice, regular orange juice or Seville orange juice, they found that the DHB-containing oranges did indeed increase absorption of the drug. The researchers report their findings in the January issue of the journal Clinical Pharmacology and Therapeutics. Watkins had previously discovered that grapefruit juice inhibits a particular digestive enzyme, which in turns allows more drug into the bloodstream. The problem is that this can be good or bad, depending on the drug and the patient.
Many drugs now carry warnings against drinking grapefruit juice with the pills.
But Watkins said he doubts drug labels will soon advise against consuming Seville oranges. For one, he noted, there is no way of knowing whether one's marmalade is made from the sour oranges. More importantly, according to Watkins, a spoonful of marmalade is unlikely to contain enough DHB to affect medications. 1998 Reuters Ltd. All rights reserved. Republication or redistribution of Reuters content is expressly prohibited without the prior written consent of Reuters.