Little-Known DANGERS of Grapefruit ! ! ! – Your Health Detective

In researching for this investigative report, I was reminded about an alarming article aptly named The Grapefruit Challenge, by a nurse named Amy Karch, MS, RN – published in American Journal of Nursing, 2004 and her gripping patient story.

Imagine being a retired upstate New Yorker, literally able to enjoy “the fruits” of your years of labor in your new role as a snowbird — trading in long, cold winters for the sun, relaxation, and fresh citrus fruits in Florida. Karch shared the sad saga of one such gentleman. After two months of wintering in Florida, he found himself in an emergency room with fatigue, muscle cramps, and a fever. What possibly could have gone awry?

Death by Grapefruit?

That patient’s story really touched my own heart, having lost my father to heart disease at the age of 47. The patient in the report had a few cardiac risk factors, including elevated cholesterol for which his doctor had started him on atorvastatin (Lipitor).

He was exercising to shed extra pounds, and like many of my own patients, he loved to juice fresh grapefruit off his own trees in Florida and pour himself two or three glasses every day.

What we didn’t know then, but do now, is that grapefruit juice contains bergamottin – a compound that interferes with your body’s ability to break down and use statin medications. This can cause a dangerous statin buildup in your body, which can result in liver damage, severe muscle and kidney damage (called rhabdomyolysis), and even death — the latter of which tragically happened to the gentleman from New York.

Additionally, the impact of grapefruit juice doesn’t end there. In the 1980s, calcium channel blockers—a class of drugs used to treat high blood pressure, angina, and arrhythmia—were the new kid on the block. By 1991, it was discovered that grapefruit juice inhibits the enzyme that metabolizes calcium channel blocking drugs—so patients could become hypotensive, with their blood pressure dropping so low that they blacked out.

And…the List goes on…and on…and on…

In addition to the cardiac drugs mentioned above, there are at least fifty known medications prescribed for cancer, depression, pain, impotence, HIV, anticoagulation, and allergies that are affected by grapefruit. It can either cause these drugs to be poorly absorbed or accumulate in your body reaching toxic levels. A quick list follows, for a complete list see

Medications that should be avoided with grapefruit

amiodarone (Cordarone)

astemizole (Hismanal)

atorvastatin (Lipitor)

budesonide (Entocort)

buspirone (BuSpar)

cerivastatin (Baycol)

cilostazol (Pletal)

cisapride (Propulsid, Prepulsid)


eletriptan (Relpax)

etoposide (Vepesid)

halofantrine (Halfan)

lovastatin (Mevacor)

mifepristone (Mifeprex)

pimozide (Orap)

quinidine (Quinaglute,


sildenafil (Viagra)

simvastatin (Zocor)

sirolimus (Rapamune)

terfenadine (Seldane)

ziprasidone (Geodon)

In 1991, Dr. David Bailey, an expert on clinical pharmacology at the University of Western Ontario, was the first scientist in the world to discover that grapefruit juice had the ability to increase the level of certain drugs in the blood. At the time it was considered a mere academic curiosity – what Dr. Bailey had discovered was just the tip of the iceberg!

Later it was discovered that grapefruit juice increases the blood level of one cholesterol-lowering drug (CLD), by as much as 15 times – it was the same as if a patient had taken 15 times the recommended dose of the drug! – increasing the risk of developing rhabdomyolysis, which causes a breakdown of muscle tissue and possible kidney failure. This is a huge price to pay for lowering blood cholesterol.

Dr. Bailey reported at that time that the effect of grapefruit juice lasts for several hours. He said, “There’s a real possibility that if a patient took the CLD with grapefruit juice for two or three weeks he would develop this complication.”

17 years later, Dr. Bailey has made another shocking discovery. He recently reported to the American Chemical Society’s national meeting in Philadelphia that grapefruit, orange, and apple juice can decrease the absorption of certain drugs such as those to treat cancer, heart disease, and those used after organ transplantation—a rather worrying situation if these drugs are essential to your survival.

So far researchers at the University of Western Ontario have identified several antibiotics that are affected by these juices such as levofloxacin, ciprofloxacin and itraconazole, and beta-blockers such as atenolol and cellprolol prescribed to treat hypertension.

The trouble is that the signs of a problem may be insidious and subtle. For instance, someone taking an antidepressant may have too much, or too little energy—depending on the specific drug interaction. Someone pumping vitamin C levels with grapefruit to fight an infection may take longer to improve despite the antibiotic they are taking, or they can develop diarrhea and deplete much needed minerals and electrolytes.

According to a more recent British study, postmenopausal women eating half a fresh grapefruit daily were 30% more likely to develop breast cancer than those not consuming the fruit, and we know that even HRT can be affected if you love your grapefruit – because it’s speculated that grapefruit may directly increase estrogen levels.

Plus, Dr. Stephen Sinatra, world renowned integrative medicine cardiologist, has cautioned men that grapefruit augments the body’s production of aromatase, an enzyme that converts testosterone to estrogen in men. He even had a patient with ED (erectile dysfunction) that was caused by daily intake of grapefruit juice. After discontinuing grapefruit juice, the ED resolved over a few weeks.

The list of grapefruit–drug interactions is so long that the FDA mandates drugs undergo testing for reactions with this fruit, and an appropriate warning label is included with each prescription. It’s reported that many patients, nurses, and doctors aren’t aware of the interactions or the potential serious consequences.

What YOU can do

First and foremost, read the labels on ANY products you take, and be aware of food–drug interactions—they are real. If you are taking anything that has a warning about grapefruit on the label, eliminate it from your diet until you can discuss your options with your doctor. He or she may even opt to change your medication.

If you’re not on a medication with a grapefruit warning label, Dr. Sinatra recommends enjoying grapefruit occasionally—not daily, avoiding hormonal changes that can be caused by grapefruit.

Recent news hints that grapefruit may increase the absorption of CoQ10, at this point there’s only cell research available — and the results are very preliminary. So there’s no concrete evidence that warrants increasing your grapefruit intake. Dr. Sinatra and health professionals like me will be following closing and reporting as evidence becomes available.

Your Health Detective:

Uncovering Clues to Add LIFE to Your Years…NOT Merely Years to Your Life, Naturally

Dr. Gloria Gilbère (aka Dr. G), N.D., D.A.Hom., Ph.D.,  D.S.C.,

EcoErgonomist, Wholistic Rejuvenist

Dr. Gilbère is renowned worldwide for her work in identifying and finding natural solutions to chemically-induced and inflammatory disorders, multiple chemical sensitivities, fibromyalgia, chronic fatigue, Gulf War Syndrome, and digestive disorders that defy conventional diagnosis and treatment. She consults worldwide via telephone and at her Institute in north Idaho. Visit her website at for details about consulting with her.

Creator of certificated courses to become a Wholistic Rejuvenist™ (CWR) and for post-graduate education for health and spa professionals. Go to and click on Wholistic Skin & Body Rejuvenation (WSBR™) for course outline. Available on-site at worldwide locations, and via distance-learning at your convenience globally.

Published by Institute for Wholistic Rejuvenation – ©2009/2010 Gloria E. Gilbère, LLC, all rights reserved.

Information in this newsletter is not meant to substitute for the advice provided by medical professionals, nor is it intended to diagnose, treat, cure or prevent a disease or disorder. The FDA has not reviewed or endorsed the contents of this educational publication.

Copyright is held by Gloria E. Gilbère, to which all rights are reserved. Other than personal, non-commercial use or forwarding, no material in this newsletter may be copied, distributed, or published without the expressed written permission of its author and copyright holder.

Karch AM. The grapefruit challenge: the juice inhibits a crucial enzyme, with possibly fatal consequences. Am J Nurs. 2004 Dec;104(12):33–35.

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John Riedl

Simply put that’s why I’ve gone down the health journey of research and creating health brands.

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