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Cathlete
Grapefruit diet nearly costs woman her leg
Updated Thu. Apr. 2 2009 6:33 PM ET
CTV.ca News Staff
Who knew that eating grapefruit three days in a row could put you at risk of leg amputation?
A case report in this week's issue of The Lancet describes how a woman developed a blood clot in her leg that was worsened by a high intake of grapefruit.
Doctors at Providence St. Peter Hospital in Olympia, Washington, say the slightly overweight woman had begun an aggressive weight-loss diet that included grapefruit every morning.
Three days after starting the diet, she went on a relatively long car ride. The next day, she felt pain radiating down her lower back to her left ankle and noticed that her leg had turned purple. She went to hospital complaining of difficulty walking, shortness of breath, and light-headedness.
An ultrasound confirmed the woman had a large clot in the veins of her left leg, from the hip down to the calf.
Doctors decided she was in danger of losing her limb to venous gangrene, and immediately sent her to the hospital's interventional radiology department. There, she had clot-busting medication injected directly into the blockage, which dissolved it.
Even after the clot dissolved, doctors found she had chronic narrowing of the large vein in her hip, which can lead to formation of blood clots. They placed a stent in the vein to widen it and by the end of the day, the woman's leg was back to normal.
Although the woman's medical history was unremarkable, she was 42 and taking birth control pills. The pills contain a synthetic form of estrogen, which can cause an increased risk of blood clots, particularly in women over 35.
When they asked about her diet, they found that she had eaten grapefruit three days in a row.
That grapefruit played a role in her dangerous blood clot, the doctors now believe.
Grapefruit can block the action of a key enzyme that normally breaks down the form of estrogen in her contraceptive. In some people, eating a lot of grapefruit can lead to a increase in drug concentration, increasing any side effects those drugs might cause -- in this case, the clot risk posed by the birth control pills.
Health Canada has issued several warnings to remind Canadians that fresh grapefruit or grapefruit juice can increase, or less commonly, decrease, the effects of some drugs. The fruit contains bioflavonoids that appear to interfere with the metabolism of many drugs.
As little as one 250 ml glass of grapefruit juice can cause an increased blood drug level and the effects can last for three days or more.
The effects vary from one person to another, from one drug to another -- and even from one grapefruit juice preparation to another. This results in an unpredictable increase in blood drug level, which can cause serious effects.
Sour oranges, such as Seville, or tangelos, a hybrid of grapefruit, may also interfere with drugs, though most other citrus, such as lemons, limes, sweet oranges and tangerines are not thought to have this effect.
Because of the unpredictable effect of grapefruit, Health Canada advises Canadians to take the following precautions:
If you are taking medication for any of the conditions listed above, do not drink grapefruit juice or eat grapefruit in any form until you have talked to your doctor and your pharmacist about the potential for an adverse reaction.
Avoid taking any drug with grapefruit juice until you have talked to your doctor or pharmacist.
Read the labels on foods and natural health products to make sure they do not contain grapefruit or its juice, or Seville oranges.
Always report any adverse drug reaction to your doctor or pharmacist immediately.
The Florida Department of Citrus also issued a statement on Thursday, saying it will be reviewing the report.
"Based on information available to date, The Lancet report looks to be inconsistent with published scientific studies which indicate grapefruit does not cause a clinically significant interaction with oral contraceptives. We are aware of no validated evidence that grapefruit affects oral contraceptives, and they are generally considered to be safe to consume with grapefruit," the Department of Citrus said.
"The industry continues to work collaboratively with leading scientific experts on food-drug interactions to evaluate research on potential drug interactions with grapefruit."
Updated Thu. Apr. 2 2009 6:33 PM ET
CTV.ca News Staff
Who knew that eating grapefruit three days in a row could put you at risk of leg amputation?
A case report in this week's issue of The Lancet describes how a woman developed a blood clot in her leg that was worsened by a high intake of grapefruit.
Doctors at Providence St. Peter Hospital in Olympia, Washington, say the slightly overweight woman had begun an aggressive weight-loss diet that included grapefruit every morning.
Three days after starting the diet, she went on a relatively long car ride. The next day, she felt pain radiating down her lower back to her left ankle and noticed that her leg had turned purple. She went to hospital complaining of difficulty walking, shortness of breath, and light-headedness.
An ultrasound confirmed the woman had a large clot in the veins of her left leg, from the hip down to the calf.
Doctors decided she was in danger of losing her limb to venous gangrene, and immediately sent her to the hospital's interventional radiology department. There, she had clot-busting medication injected directly into the blockage, which dissolved it.
Even after the clot dissolved, doctors found she had chronic narrowing of the large vein in her hip, which can lead to formation of blood clots. They placed a stent in the vein to widen it and by the end of the day, the woman's leg was back to normal.
Although the woman's medical history was unremarkable, she was 42 and taking birth control pills. The pills contain a synthetic form of estrogen, which can cause an increased risk of blood clots, particularly in women over 35.
When they asked about her diet, they found that she had eaten grapefruit three days in a row.
That grapefruit played a role in her dangerous blood clot, the doctors now believe.
Grapefruit can block the action of a key enzyme that normally breaks down the form of estrogen in her contraceptive. In some people, eating a lot of grapefruit can lead to a increase in drug concentration, increasing any side effects those drugs might cause -- in this case, the clot risk posed by the birth control pills.
Health Canada has issued several warnings to remind Canadians that fresh grapefruit or grapefruit juice can increase, or less commonly, decrease, the effects of some drugs. The fruit contains bioflavonoids that appear to interfere with the metabolism of many drugs.
As little as one 250 ml glass of grapefruit juice can cause an increased blood drug level and the effects can last for three days or more.
The effects vary from one person to another, from one drug to another -- and even from one grapefruit juice preparation to another. This results in an unpredictable increase in blood drug level, which can cause serious effects.
Sour oranges, such as Seville, or tangelos, a hybrid of grapefruit, may also interfere with drugs, though most other citrus, such as lemons, limes, sweet oranges and tangerines are not thought to have this effect.
Because of the unpredictable effect of grapefruit, Health Canada advises Canadians to take the following precautions:
If you are taking medication for any of the conditions listed above, do not drink grapefruit juice or eat grapefruit in any form until you have talked to your doctor and your pharmacist about the potential for an adverse reaction.
Avoid taking any drug with grapefruit juice until you have talked to your doctor or pharmacist.
Read the labels on foods and natural health products to make sure they do not contain grapefruit or its juice, or Seville oranges.
Always report any adverse drug reaction to your doctor or pharmacist immediately.
The Florida Department of Citrus also issued a statement on Thursday, saying it will be reviewing the report.
"Based on information available to date, The Lancet report looks to be inconsistent with published scientific studies which indicate grapefruit does not cause a clinically significant interaction with oral contraceptives. We are aware of no validated evidence that grapefruit affects oral contraceptives, and they are generally considered to be safe to consume with grapefruit," the Department of Citrus said.
"The industry continues to work collaboratively with leading scientific experts on food-drug interactions to evaluate research on potential drug interactions with grapefruit."
