Have you ever 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, grapefruit can affect the rate at which drugs are processed by the liver.
That can be dangerous, because slower breakdown of the drug means you’ll have more of the drug in your bloodstream. This can cause certain side effects and affect how well the drug works.
One such drug group that has a serious interaction with grapefruit is statins.
Statins are prescription drugs used to lower cholesterol. They prevent your body from making more cholesterol and can help your body reabsorb the cholesterol already present in your artery walls.
Not everybody with high cholesterol levels needs to take statins. The drug is recommended for people who are at a high risk for heart disease. Individuals with a family history of cardiovascular disease and high cholesterol might need to take statins. Other risk factors such as being overweight or having diabetes might warrant statin use as well.
The secret to the interaction between grapefruits and statins is in furanocoumarins, according to a study published in The American Journal of Clinical Nutrition. Furanocoumarins are organic chemical compounds present in many different plants, including grapefruit.
The furanocoumarins inhibit the efficacy of an important enzyme. This enzyme normally helps your body process the medication you take, balancing out how much of it goes into your bloodstream. Because furanocoumarins hinder this enzyme, larger amounts of the drug persist your bloodstream.
The major risk of mixing statins and grapefruit is increasing the side effects of the drugs. The FDA reports that this could put you at risk for muscle breakdown, liver damage and kidney failure.
Statins also carry other risks, such as digestive problems, increased blood sugar and neurological side effects, including confusion and memory loss, according to Mayo Clinic. Women and people over 65 years old are at a higher risk of developing side effects from statins.
It’s not only statins and grapefruit that don’t mix. A number of other medications also shouldn’t be taken alongside with grapefruit including many drugs used to treat blood vessel and heart conditions.
Grapefruit also interacts with drugs used to treat nausea and urinary tract infections, immunosuppressants, 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 are taking some antihistamines, such as Allegra.
Not all statins interact in the same way with grapefruit. According to research published in BMJ, the interaction is particularly strong with two types of statins: simvastatin (Zocor) and atorvastatin (Lipitor). If you’re taking a different type of statin, ask your doctor about the risk of interaction.
The interaction between grapefruit and medications poses dangers only if you are taking the drug orally because the interaction occurs in the digestive tract. If you use a skin patch or receive your medication through an injection, you may be safe.
According to the National Health Service, just one grapefruit or one glass of grapefruit juice could be enough to cause an interaction with some medications. Both fresh and frozen juice have the same effect.
Unfortunately, doctors don’t know how common these interactions occur. Not everybody has the same reaction when mixing grapefruit and statins. Also, some people might be able to separate grapefruit and medication use and have no side effects. For other people, just taking statins and grapefruit on the same day (even hours apart) could cause side effects.
To be safe, restrict drinking and eating grapefruit if you take statins until you talk to your doctor about the risk.
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, but not all. For example, you might need to stop taking simvastatin or atorvastatin, but you might be able to take a different statin.
If you have doubts or questions, talk to your doctor about the risks of mixing medications and grapefruit.