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Do you start the day with a fresh grapefruit or a glass or grapefruit juice? Lots of people enjoy the tart taste of fresh grapefruit juice and think they’re doing something good for themselves when they drink it.
After all, fruits and vegetables are good for you, right? We certainly preach about their health benefits a lot. Well, if you check in our vegetable crisper, you won’t find a grapefruit or a carton or grapefruit juice.
Why do we avoid this fruit? Keep reading to find out.
Is Grapefruit Juice Good for You?
When grapefruits were first identified hundreds of years ago it was called the “forbidden fruit.” That’s an appropriate name as you’ll soon find out.
Not that grapefruit doesn’t have health benefits – it’s a good source of vitamin C, fiber and an antioxidant called lycopene. Many years ago grapefruit diets were popular because eating grapefruit was believed to boost your metabolism and help with weight loss.
So what’s not to love about grapefruits and grapefruit juice? Grapefruits are high in vitamin C and a good source of the important minerals calcium and potassium.
Here’s the dark side of eating grapefruits and drinking their juice. If you’re taking medications, drinking grapefruit juice can be downright dangerous.
Grapefruit Side Effects: Grapefruit Juice Alters Medication Levels
Drinking even modest amounts of grapefruit juice, as little as a glass a day, increases the blood levels of many prescription medications. The best-known example of medications that are affected by grapefruit juice are statin medications, medications that lower cholesterol – but these aren’t the only ones.
Levels of some antibiotics, high blood pressure medications, antihistamines, muscle relaxants and heart medications are impacted too. In fact, if you take any medications you should probably avoid drinking grapefruit juice.
Why is grapefruit juice such a problem if you take medications? The active compounds in grapefruits that do this are called furanocoumarins, chemicals that protect plants against insects.
Furanocoumarins alter the activity of enzymes that break down medications, making it easier for the medications to build up in your bloodstream.
Altering the levels of some medications may not be a problem but for others like heart medications, the results can be deadly.
Does Grapefruit Alter Hormone Levels Too?
Hormones like estrogen are broken down by the liver. This makes us think grapefruit alters estrogen levels too. Here’s an actual example. A friend I know had a mammogram. It showed her breasts were extremely dense, much denser than on her previous mammogram.
She was also having problems with breast pain and nodularity. The radiologist asked if she were taking a supplement that might be raising her estrogen levels and making her breasts denser and more nodularity.
As it turns out the only thing she was using that was new was a Stevia sweetener with grapefruit seed extract added as a preservative. She stopped using the sweetener and her breast pain and nodularity disappeared in a matter of weeks. Her mammogram the following year showed a dramatic reduction in breast density.
Was grapefruit seed extract causing her estrogen levels to rise, leading to the breast density and nodularity she was experiencing? That’s what we think. As a result, we believe it’s a good idea to avoid drinking grapefruit juice or eating grapefruit if you’re female.
On what basis do we say this? If you interfere with the breakdown of estrogen, you have more floating around in your system to stimulate breast tissue and increase your risk for breast cancer.
Is there any proof that grapefruit juice increases the risk of breast cancer? A study carried out in 2007 showed eating as little of a quarter of a grapefruit daily was linked with a 30% increase in breast cancer in post-menopausal women. Here’s a link to the study.
What about Other Citrus Juices?
Can you substitute orange juice for grapefruit juice safely? There is some evidence that orange juice alters the levels of some medications too but this hasn’t been studied to the same degree as grapefruit juice. We suggest using caution with orange juice too. Plus, orange juice is high in natural sugar.
What if you eat grapefruit in the morning and take your medications at night? Probably not good enough. Grapefruit can have an impact on some medications up to 24 hours after eating it or drinking the juice. It’s also possible for grapefruit and grapefruit juice to interact with supplements as well.
Find another source of vitamin C – other than grapefruit – especially if you take prescription medications or supplements. When you buy products, make sure they don’t contain grapefruit seed extract. The effect of grapefruit and grapefruit juice on medications is very real. Why take chances?
British Journal of Cancer (2007) 97, 440–445. doi:10.1038/sj.bjc.6603880 www.bjcancer.com
Drugs.com. “Drug Interactions with Grapefruit Juice”
Medscape Family Medicine. “Drugs That Interact With Grapefruit on the Rise”