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This Is How Grapefruit Meddles With Your Medication

Jana is a strong believer in ingredient safety and transparency. She inspects cosmetics and food products to oust unhealthy goobers.


What Is Grapefruit?

You probably already know what it looks like and that it’s a citrus fruit. But I could not resist a few interesting facts.

  • Grapefruit is a hybrid creature. Mom was an orange and Dad was a pomelo. Or the other way around but grapefruit really are orange-pomelo crossings.
  • The fruit hangs in clusters similar to grapes. Hence the name.
  • It first appeared in the 18th century, making grapefruit only 300 years old.
  • The grapefruit has its own hybrid offspring, the tangelo. The latter was born when grapefruit was crossed with tangerines.

What Are The Benefits Of Grapefruit?

There are many so many benefits that the topic deserves its own article. But let’s have a quick overview of some of the most important perks that this fruit has to offer.

Grapefruit is low in calories and packed with nutrients like Vitamin C and potassium. Studies have shown that the fruit can prevent or stall certain conditions and diseases. These include cancer, diabetes type 2, stroke, obesity, high blood pressure, and a poor immune system.

Is Grapefruit Really Such A Threat?

When taken without certain medicines or in small amounts, grapefruit is probably not lethal. However, its ability to interact with medication worried the Food and Drug Administration (FDA) so much that it decided to act. The FDA now requires certain over-the-counter drugs and prescription medications to warn against munching too much grapefruit while using the medicine.


How Does Grapefruit Interfere With Medication?

To answer this question, one must first look at something else. More specifically, the life cycle of medication inside the body. After a person consumes a pill, the body will eventually break it down. But in order to do that, the small intestine needs an enzyme called CYP3A4. Pharmaceuticals are designed to take this natural digestive function into account so that they can release the correct dosage into the bloodstream.

Long story short, grapefruit blocks CYP3A4. The result? Too much drugs enter the bloodstream. At the risk of sounding overly dramatic, this is kind of like a tiny overdose. Having too much of a certain drug can increase its side-effects. Grapefruit can also cause the opposite to happen. By allowing too little of a drug to enter the bloodstream, it prevents a person from getting their full dosage. This can be worrying when medication is taken to control a serious condition.

What Medications Are Most At Risk?

This list is by no means complete. If you are concerned that your grapefruit obsession and sinus tablets might not mix, it’s important to read the medication guide (that scary paper with all the warnings inside the box) - or simply to ask your doctor.

  1. Antihistamines. Allegra (fexofenadine) is one example of a drug that grapefruit can reduce in the bloodstream and thus lower its effectiveness.
  2. Medication for high blood pressure.
  3. Heart medication, including those for abnormal heart rhythms.
  4. Drugs to lower cholesterol.
  5. Anti-rejection drugs for organ-transplant patients.
  6. Anxiety medication, especially buspirone.
  7. Medication for Crohn’s disease.
  8. Artemether (Artenam, Paluther).
  9. Seizure medications, including carbamazepine (Tegretol).
  10. Carvedilol (Coreg).
  11. Estrogens.
  12. Itraconazole (Sporanox).
  13. Sedative medications (Benzodiazepines).
  14. Sildenafil (Viagra).
Grapefruit is a popular breakfast snack.

Grapefruit is a popular breakfast snack.

Grapefruit Does Not Always Affect Medication

In a perfect world, things would be straightforward. Grapefruit would mess with certain medications in a certain way and we would know exactly what to expect and what to do. This is unfortunately not the case.

The effects of grapefruit on medicine are unpredictable. The severity of a reaction depends on several factors and a mix thereof. The biology of the person, what type of drug, whether the grapefruit interferes at all, and how much of the fruit or its juice was consumed.

A Short Summary

Grapefruit is a delicious citrus fruit that contains many nutrients essential to our well-being. Most notably, potassium and Vitamin C. Several studies support this fruit’s role in a healthy lifestyle. Unfortunately, grapefruit tangos with an enzyme that breaks down medications. This can lead to medicine being consumed in too large doses or not being as effective as they should be. To safely enjoy this beautiful fruit, one must read the information leaflet of any drugs you are taking or to talk to a health care professional.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2020 Jana Louise Smit


Lorna Lamon on November 03, 2020:

This information is certainly worth bearing in mind. I love grapefruit juice and regularly have it with breakfast. I am sure many people are not aware of this Jana, so thank you for sharing this important information.

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