You’ve probably heard warnings about drug-food interactions such as how grapefruit can interact with prescription drugs. You may have seen it written on a pill bottle, or been told by a well-meaning friend as you were about to dig into a nice juicy grapefruit.
For many people, that’s where the awareness ends. They just have a vague idea that grapefruit and prescriptions don’t mix. But that leaves a lot of questions unanswered.
- How does grapefruit affect drugs?
- Does it intensify their effects or reduce them?
- Is it dangerous?
- Are there other drug-food interactions you should know about?
We’re going to answer these questions. Once you know more about how foods can affect the prescription drugs you take, you can be confident that your medications are doing their job properly.
Before we start, here’s an important reminder: whenever you’re in doubt, talk to your doctor or pharmacist!
How Grapefruit Affects Drugs
Believe it or not, one glass of grapefruit juice or a single grapefruit is enough to change the way your body breaks down drugs, and the effects can last up to three days! This is also true for some other closely-related fruits: Seville oranges, tangelos, pomelos and Minneolas.
That’s because these fruits have a class of chemicals that disrupt proteins in your liver and small intestine. And those proteins are responsible for breaking down certain drugs.
By disrupting those proteins, the fruit can slow down the way your body processes medications. The result is increased levels of the drug in your blood and intensified side effects—which can be dangerous.
Here’s a list of common types of medications that can interact with grapefruit, and what types of effects it causes:
- Cholesterol medications: increased chances of muscle weakness, pain, and kidney damage.
- Blood pressure medications: increased chance of a rapid drop in blood pressure which can be dangerous.
- Heart rhythm medications: can cause dangerous heart rhythm changes.
- Depression and anxiety medications: can cause dizziness and excessive sleepiness.
- Erectile dysfunction medications: increased dizziness and low blood pressure.
Should I Stop Eating Grapefruit?
Grapefruit can offer many health benefits. To name just a few, it’s high in fibre, vitamins, and antioxidants—yet low in calories.
So if you can include it in your diet, you should. And the chances are that you can. Grapefruit only affects a relatively small number of drugs. The best idea is to speak to your doctor or pharmacist and take advantage of their expertise.
Other Drug-Food Interactions
There are many other possible drug-food interactions that you may not know about. Here are some you should be aware of in case you’re taking any of the following drugs.
- Potassium-rich foods (bananas, avocados, beets, potatoes, etc) can interact with ACE inhibitor medications, leading to arrhythmia and heart palpitations.
- Milk and other dairy products can stop antibiotics from working. You should leave a two-hour window between eating dairy and taking the antibiotic (both before and after).
- Spinach, kale, cabbage, and broccoli have high levels of vitamin K, which promotes blood clotting. This can counteract the effects of blood-thinning medications.
- A high-fibre diet slows the rate that your stomach empties, which can slow the rate that some medications are absorbed.
- Black licorice or licorice root supplements contain a compound that can counteract heart rhythm medications
Now you know a little more about how grapefruit can interact with your prescription drugs, and some other common drug-food interactions. Remember that there are many forms of each type of drug listed in this post. So just because you’re on blood pressure meds doesn’t mean you need to swear off grapefruit.
It all depends on the exact drug, your diet, and a range of other factors. As you can see, it gets a little complicated. So whenever you’re being prescribed a new medication or notice an increase in a drug’s side effects, don’t hesitate to bring it up with your doctor or pharmacist. Bon appetite!