Over the years, I have had friends and relatives tell me that they cannot eat grapefruit or drink grapefruit juice because it impacts the medication they were taking. I have always wondered why. None of them seem to know. They only know that grapefruit negatively interacts with some medications.
I did a little research and discovered a long list of medications that negatively interacts with grapefruits. More specifically, furanocoumarin, which is the compound found in grapefruit, affects the ability of your medicine to be absorbed into your system in some instances, or significantly boosts the absorption rate in other instances. Some medicines have little to no effect when combined with grapefruit whereas other medicines can be boosted to toxic levels with even a small glass of juice or even a few bites of grapefruit.
But the fascinating thing is – well, fascinating to me at least – is how this grapefruit connection was discovered. During a clinical trial, a pharmaceutical company wanted to determine whether alcohol would interact with the drug felodipine (a calcium channel blocker that is most commonly used in the treatment of high blood pressure). To mask the taste of the alcohol, they stirred some grapefruit juice in it. They figured out that the grapefruit juice caused felodipine’s effects, and those side effects were greatly increased. The researchers initially thought it was the alcohol that was causing this effect but they soon realized it was the grapefruit juice. Further studies showed similar results for other medicines too.
The compound in grapefruit is also found in other citrus too, but for some reason, the problem is of the greatest magnitude with the grapefruit. I feel sorry for those who go through this. I love grapefruit and would be sad if I couldn’t eat it.