Dear HEALTHbeat subscriber,

Like many of you, I am always looking for simple things that can yield big health gains, whether it's remembering to wear sunscreen, walking to the mailbox instead of driving, or eating a variety of fruits and vegetables. These little steps make me feel like I’m doing something good for myself and my family. This issue of HEALTHbeat addresses the potential benefits of foods rich in antioxidants—are they worth the effort? Also, a Q&A from the Harvard Health Letter addresses a reader question about whether taking aspirin with grapefruit juice is risky.

Wishing you good health,


Nancy Ferrari
Managing Editor
Harvard Health Publications
HEALTHbeat@hms.harvard.edu

Q: I am 78, and for about 10 years, I have been taking an 81-mg aspirin every morning with a glass of grapefruit juice. I heard that it’s not a good idea to drink grapefruit juice with some blood-thinning drugs. Is that true of aspirin too?

A: Like you and millions of other people, I love the taste of grapefruit juice. It also has many health-promoting substances in it. However, around 1987 it was accidentally discovered that grapefruit juice can change the blood levels of many drugs, raising several of them and lowering a few others. As you might imagine, these changes can cause side effects or reduce a drug’s effectiveness. Whether a drug is affected by grapefruit juice depends on how it’s metabolized in the liver.

Although most medications aren’t affected, some of the most commonly prescribed ones are. These include several of the cholesterol-lowering statin drugs, several calcium-channel blockers, the blood pressure drug losartan (Cozaar), several sedatives and sleeping pills, and drugs for erectile dysfunction, such as sildenafil (Viagra). To make things more complicated, the effects of grapefruit juice on the levels of a particular drug can be quite variable from one person to the next.

As to your question, grapefruit juice does have a mild effect on the blood-thinning drug warfarin (Coumadin). But I cannot find any solid evidence that it interacts with aspirin, which, like warfarin, reduces the tendency of blood to clot.

So what to do if you enjoy drinking grapefruit juice? Some drugs, including those in the same class, interact with grapefruit juice more than others. Talk to your doctor about the medications you’re taking and whether there might be alternatives. However, understand that not every drug has been tested for possible interaction with grapefruit juice. Because of the uncertainty, and because I’m taking a statin drug that interacts with grapefruit juice, I have chosen to switch to orange juice in the mornings — just to play it safe. But I sure miss that tangy taste.

— Anthony L. Komaroff, M.D.,
Harvard Health Letter Editor in Chief

This Question and Answer first appeared in the June 2007 Harvard Health Letter, available at www.health.harvard.edu/health.

Harvard Medical School publishes authoritative Special Health Reports on a wide range of topics. Each report delivers practical information on diagnosis, treatment, and prevention of major health concerns in clear, easy-to-understand language. For more information on a specific topic, click the appropriate link below:

Alzheimer’s, Arthritis, Bladder, Cholesterol, Depression, Diabetes, Digestion, Energy, Exercise, Eye Disease, Headache, Heart Disease, High Blood Pressure, Memory, Menopause, Prostate, Sexuality, Sleep, Stroke, Vitamins