Grapefruit is one of the healthiest citrus fruits you can eat. It’s rich in antioxidants, vitamins, and fiber.

However, have you heard that you shouldn’t mix grapefruit and certain medications? As it turns out, this claim is true.

According to the U.S. Food and Drug Administration (FDA), grapefruit can affect the rate that your liver processes drugs. This is dangerous.

A slower breakdown of a drug means you’ll have more of that drug in your bloodstream. More of the drug in your bloodstream can cause certain side effects and affect how well the drug works.

So, which medications should you avoid mixing with grapefruit and grapefruit juice?

The drugs that can interact with this citrus fruit includes statins. This doesn’t mean that you have to avoid grapefruit altogether if you’re prescribed this medication.

The fruit doesn’t affect all statins. Depending on which drug your doctor prescribes, you might not have to give up grapefruit at all.

Statins are prescription drugs used to lower cholesterol. They prevent your body from making more cholesterol. They also help your body reabsorb cholesterol that’s already present in your artery walls.

There different types of statins. They include:

  • atorvastatin (Lipitor)
  • lovastatin (Mevacor)
  • simvastatin (Zocor)
  • fluvastatin (Lescol)
  • pitavastatin (Livalo)
  • pravastatin (Pravachol)
  • rosuvastatin (Crestor)

Everyone with high cholesterol doesn’t need to take statins. Some people can lower their cholesterol with lifestyle changes.

Lifestyle changes include:

Statins are recommended if you have a:

  • high risk for heart disease
  • family history of heart disease
  • family history of high cholesterol

Being overweight or having diabetes might require statin use as well.

If you’re prescribed a statin, it’s important to understand which ones can interact negatively with grapefruit and grapefruit juice.

One misconception is that you shouldn’t mix grapefruit with any statin drug. For this reason, you might avoid the fruit altogether.

You only need to avoid grapefruit if your doctor prescribes lovastatin, atorvastatin, or simvastatin.

The secret to the interaction between grapefruit and these statins is in furanocoumarins, according to a 2017 study. Furanocoumarins are organic chemical compounds present in many different plants, including grapefruit.

This compound deactivates the CYP3A4 enzyme that the body uses to metabolize, or process, these particular statins. Grapefruit doesn’t affect other statins because they are metabolized by a different enzyme, CYP2C9.

Interestingly, the interaction between grapefruit and medications poses a danger only when taken orally. This is because the interaction happens in your digestive tract. If you use a skin patch or receive your medication through an injection, you may have a lower risk of adverse effects.

There’s the risk of increased side effects when mixing grapefruit with lovastatin, atorvastatin, or simvastatin.

Women and people ages 65 and older are at a higher risk of developing side effects from these statins.

Side effects include:

Milder side effects include muscle and joint pain.

The FDA reports that the risk of muscle breakdown and liver damage can lead to kidney failure. Neurological side effects include confusion and memory loss, according to the Mayo Clinic.

The exact amount of grapefruit it takes to have a negative reaction when taking lovastatin, atorvastatin, or simvastatin is unknown.

Just one grapefruit or one glass of grapefruit juice could be enough to cause an interaction in some people. Others may need to consume more of the fruit or juice to have an interaction.

Keep in mind that both fresh and frozen juices have the same effect.

According to the Cleveland Clinic, there are instance when consuming moderate amounts of grapefruit appear to be safe. Most incidents of negative reactions involved consuming large amounts of grapefruit.

If you accidentally consume a small amount of grapefruit, it isn’t likely to affect your medication. However, check with your doctor if you experience ill effects, since it’s unclear how common these interactions are.

No one has the same reaction when mixing grapefruit with lovastatin, atorvastatin, or simvastatin. Err on the side of caution and restrict drinking and eating grapefruit if you take one of these statins, at least until you discuss the risks with your doctor.

It’s also recommended to avoid grapefruit juice when taking other medications, too.

Be mindful that other citrus fruits might also interact with lovastatin, atorvastatin, and simvastatin. The list includes tangelos, pomelos, bitter oranges, and Seville oranges. These foods can also affect how your body metabolizes the medication.

There have been no documented problems with lemons, tangerines, clementines, mandarins, navel oranges, and blood oranges.

It’s not only lovastatin, atorvastatin, and simvastatin that don’t mix with grapefruit. A number of other medications also shouldn’t be taken with grapefruit. These include many drugs used to treat blood vessel and heart conditions.

Grapefruit also interacts with drugs used to treat nausea and urinary tract infections, anti-rejection drugs, medications to treat cancer, and many drugs that affect the central nervous system, including anti-anxiety drugs.

According to the FDA, grapefruit might also affect your body if you’re taking allergy medication, such as fexofenadine (Allegra).

Similar to how it affects certain statins, furanocoumarins in grapefruit can suppress the enzyme that helps your body process these medications. The compound hinders this enzyme, creating larger amounts of drugs in your bloodstream.

Although grapefruit interacts with over 85 medications, not all of the interactions cause serious side effects. Sometimes, grapefruit interacts with only some of the drugs in a category, not all.

For example, you might need to stop taking lovastatin, atorvastatin, or simvastatin, but you might be able to take fluvastatin, pitavastatin, pravastatin, or rosuvastatin to lower your cholesterol.

If you have doubts or questions, talk to your doctor about the risks of mixing medications and grapefruit.

Q:

If I have a grapefruit or glass of grapefruit juice, is there a safe amount of time I should wait before taking my medication or vice versa?

A:

The effect of grapefruit juice on some drugs may last longer than 24 hours and avoiding drinking any grapefruit juice is wise advice. Eating half a grapefruit is probably less risky because it contains a relatively small amount of juice but could still have an effect. To be safe, check with your doctor if you take one of the three statins mentioned above.

Alan Carter, PharmDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.