Buzz
We’re used to warnings like “May cause drowsiness” or “Avoid alcohol while using this medication.” But what about the warning that says, “Never consume grapefruit or grapefruit juice while on this medication”? What’s the deal with that?
It’s all about the enzymes, folks. Specifically, the CYP3A4 enzyme, which plays a key role in helping your body process, absorb, and utilize various medications.
Grapefruit (Citrus x paradisi) and its juice contain compounds that disrupt the activity of CYP3A4, preventing it from functioning correctly. Depending on the medication, this can result in your body absorbing too much of the drug, possibly leading to an overdose, or too little, making the drug ineffective.
Michael J. Ermarth for the U.S. Food and Drug Administration
It’s not just about grapefruit either.
“There are numerous factors that can influence how effective a drug is,” says Dr. Rob Menzies, a pulmonary and critical care specialist, in an interview with mental_floss.
Seville oranges (the type commonly found in marmalade) and tangelos also act as CYP3A4 inhibitors. Dairy products and dark leafy greens like spinach and kale can interfere with other metabolic processes.
And don't forget about your other medications.
“The primary concern comes from polypharmacy (taking several medications simultaneously),” Menzies explains, “as many drugs can influence the effects of others.”
Review your medication labels and pay attention to those warnings; they’re not just there for decoration.
If you're unsure about how your medications might interact with certain foods, other drugs, or supplements, consult with your doctor or pharmacist.
