Diets rich in fruits, vegetables and dairy products are essential to good health. However, if you are taking certain medications, some of these items should be eaten in moderation or possibly not eaten at all. Food and drug interactions can be as dangerous as those caused by drinking alcohol while taking certain medications (see Lifelines, Don’t Mix Your Medications with Alcohol) or by taking more than one medication within the same dosing period without consulting your health care provider.

“Diet should be part of any discussion with your health care provider about medication, regardless of whether it is prescribed or available over the counter,” says LHSFNA Management Co-Chairman Noel C. Borck. “Knowing what you should or should not be eating before you start taking a new medication helps ensure its effectiveness and your safety.”

Here are just a few food items that don’t mix well with some common medications:

• Grapefruit and Statins, Calcium Channel Blockers, Antihistamines and Antibiotics: Grapefruits are an excellent source of vitamin C which is essential for helping the body heal and fight disease. However, they also contain furanocoumarins, chemical compounds that affect the body’s ability to metabolize drugs. This can lead to toxic levels of medication in your system that can cause muscle breakdown, liver damage and kidney failure. Click here for a list of medications that can interact dangerously with grapefruit.

• Bananas and Beta-Blockers: Bananas are full of potassium, which among other things, helps to maintain the electrical activity of the heart. Beta-blockers that are often prescribed to treat heart disease and high blood pressure also contain potassium. Too much potassium can lead to erratic heart rhythm and kidney failure. If you are taking a beta-blocker, your health care provider may recommend that you limit your consumption of bananas and other high potassium foods including papaya, tomato, avocado and kale.

• Spinach and Blood Thinners: Green leafy vegetables including spinach, kale and collards contain vitamin K, also known as the “clotting vitamin,” because without vitamin K blood would not clot. This is why if you are taking a blood thinner such as warfarin (Coumadin) or enoxaparin (Lovenox), these vegetables may be among those you should eat less of or not at all. According to the National Institutes of Health Drug-Nutrient Interaction Task Force, people who are taking blood thinners should limit their daily servings of green leafy vegetables and all other vegetables and fruits that contain vitamin K.

• Milk and Antibiotics: Calcium in milk is essential for strong bones and teeth. However, it also affects the absorption of tetracyclines. These are a class of antibiotics widely used in treating a number of bacterial illnesses, including urinary tract infections, sexually transmitted diseases, strep throat, ear infections and acne. Tetracycline should be taken with a full glass of water on an empty stomach, at least one hour before or two hours after meals or snacks. Do not take tetracycline with food, especially dairy products such as milk, yogurt, cheese and ice cream. Doing so can make this drug less effective.

Take steps to protect yourself from dangerous food and drug interactions. Always read medication labels before taking any prescription or over-the-counter medication. Talk to your health care provider and your pharmacist when you have questions.

The U.S. Food and Drug Administration (FDA) has assembled a guide that provides in-depth information about food and drug interactions. Download it here.

You can find out more about medication interactions with food along with medication interactions with alcohol at www.drugs.com/drug_interactions.php.

[Janet Lubman Rathner]