Grapefruit poses a potentially lethal health risk to more and more patients taking prescription drugs. The fruit contains chemicals called furanocoumarins that can interact with certain drugs, blocking their breakdown and so making them more potent. Adverse effects can include acute kidney failure, respiratory failure, internal bleeding and sudden death.
From eating a lousy grapefruit?
While it is well known that some patients should avoid grapefruit, or grapefruit juice, the list of drugs involved has risen sharply in recent years. More than 85 current drugs can interact with grapefruit, and of these 43 can have serious side effects, according to scientists writing in the Canadian Medical Association Journal.
The important thing is to be savvy and know about this. You may know someone taking one or more meds, who likes to dive into citrus fruits. It’s not just grapefruit; other citrus fruit can also cause the problem, like limes and oranges (so, think marmalade), also contain furanocoumarins. These chemicals act on an enzyme in the gut that normally reduces the potency of medication. This can effectively boost the blood levels of certain drugs, sometimes to dangerous levels.
A modest single helping of grapefruit can have an effect even if consumed hours before a drug is taken. Frequent exposure to grapefruit could make matters worse. Combining the cholesterol-lowering drug simvastatin with a 200-millilitre glass of grapefruit juice once a day (approximately 7 US fluid ounces) for three days more than trebled the concentration level of the statin.
Many furanocoumarins are toxic and are produced by plants as a defense mechanism against various types of predators ranging from insects to mammals. They can also cause a sunlight-sensitive skin rash. Bergamottin is one of them; that’s the main flavor in Earl Grey tea, though I’ve never heard of the tea causing problems.
Of course the real problem is with the drugs, not the humble grapefruit. He was here first!
However, I noticed from the late 70s the citrus fruits are common food allergy offenders and they are on my elimination diet banned list.
Check out my ground-breaking book “Diet Wise” for more (much more) on food interactions of the sort you wouldn’t believe and you would never guess! Foods are NOT friendly on the whole…
See it reviewed here: Diet Wise Book