Doctors have warned of a "lack of knowledge" about the dangers of mixing some medications with grapefruit.
The fruit can cause overdoses of some drugs by stopping the medicines being broken down in the intestines and the liver.
The researchers who first identified the link said the number of drugs that became dangerous with grapefruit was increasing rapidly.
They were writing in the Canadian Medical Association Journal.
The team at the Lawson Health Research Institute in Canada said the number of drugs which had serious side effects with grapefruit had gone from 17 in 2008 to 43 in 2012.
They include some drugs for a range of conditions including blood pressure, cancer and cholesterol-lowering statins and those taken to suppress the immune system after an organ transplant.
Chemicals in grapefruit, furanocoumarins, wipe out an enzyme which breaks the drugs down. It means much more of the drug escapes the digestive system than the body can handle.
Three times the levels of one blood pressure drug, felodipine, was reported after patients had a glass of grapefruit juice compared with a glass of water.
The side effects are varied depending on the drug, but include stomach bleeds, altered heart beat, kidney damage and sudden death.
Dr David Bailey, one of the researchers, told the BBC: "One tablet with a glass of grapefruit juice can be like taking five or 10 tablets with a glass of water and people say I don't believe it, but I can show you that scientifically it is sound.
"So you can unintentionally go from a therapeutic level to a toxic level just by consuming grapefruit juice."
The report said: "We contend that there remains a lack of knowledge about this interaction in the general health care community."
They added: "Unless health care professionals are aware of the possibility that the adverse event they are seeing might have an origin in the recent addition of grapefruit to the patient's diet, it is very unlikely that they will investigate it."
Other citrus fruits such as Seville oranges, often used in marmalade, and limes have the same effect.
Neal Patel, from the Royal Pharmaceutical Society said: "Grapefruit isn't the only food that can cause issues, for example milk can stop the absorption of some antibiotics if taken at the same time.
"Although some of these interactions may not be clinically significant, some may lead to more serious outcomes.
"Pharmacists are the best port of call for anyone concerned about how their diet may affect their medication. Information about any interactions would always be included in the patient information leaflet that comes with the medicine."
Grapefruit, not good for you.
Grapefruit, not good for you.
“If you trust in yourself, and believe in your dreams, and follow your star. . . you'll still get beaten by people who spent their time working hard and learning things and weren't so lazy.”
Re: Grapefruit, not good for you.
Yup -- my Mom is on variety of heart and bp drugs and cannot have grapefruit at all. Too bad, she used to eat it all the time, but small sacrifice to make for the drugs to work properly.
“I ask no favor for my sex. All I ask of our brethren is that they take their feet off our necks.” ~ Ruth Bader Ginsburg, paraphrasing Sarah Moore Grimké
Re: Grapefruit, not good for you.
I'm always delighted when I learn that something I can't stand isn't good for you...
Now if only the opposite could be proven true....
Pizza: The Wonder Drug....
Now if only the opposite could be proven true....
Pizza: The Wonder Drug....



Re: Grapefruit, not good for you.
well it can raise my blood sugar to over 400 in no time
Okay... There's all kinds of things wrong with what you just said.
Re: Grapefruit, not good for you.
The line always was that eating grapefruit helped you lose weight...
Well of course it did...
After forcing down a couple of pieces of it, it had such a negative effect on your taste buds you didn't want to eat anything else....
Well of course it did...
After forcing down a couple of pieces of it, it had such a negative effect on your taste buds you didn't want to eat anything else....



Re: Grapefruit, not good for you.
Excuse me, I think i'll have some grapefruit juice (unsweetened!) now. :p
Bummer. I love grapefruit.
Bummer. I love grapefruit.
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Re: Grapefruit, not good for you.
The Leonard Cohen of fruits?Lord Jim wrote:The line always was that eating grapefruit helped you lose weight...
Well of course it did...
After forcing down a couple of pieces of it, it had such a negative effect on your taste buds you didn't want to eat anything else....
For Christianity, by identifying truth with faith, must teach-and, properly understood, does teach-that any interference with the truth is immoral. A Christian with faith has nothing to fear from the facts