Be careful about eating grapefruit if you are one of the many Americans taking a statin drug to lower your cholesterol, nutrition experts at UT Southwestern Medical Center warn.

Grapefruit contains chemicals called furanocoumarins that interfere with an enzyme involved in metabolizing many of the statin drugs, including atorvastatin, lovastatin, and simvastatin. Regularly eating grapefruit or drinking grapefruit juice could lead to an excessive buildup of the drug, says Lona Sandon, clinical nutritionist at UT Southwestern.

Other foods that can interfere with medications for heart disease or heart disease-risk factors:

• Vitamin K consumption affects warfarin, an anticoagulant that is frequently taken by patients with atrial fibrillation. Vitamin K is found in dark green vegetables like spinach, kale, broccoli and collard greens. “People taking warfarin can still consume foods containing vitamin K. The key is to be consistent with how much they eat of them day to day,” Sandon says. “This allows the doctor to adjust the warfarin dose accordingly.”
• Fish oil supplements can enhance the effects of warfarin with a potentially dangerous outcome.
• Individuals who are taking digoxin for heart failure may need to avoid black licorice, which affects potassium levels. Black licorice can also interfere with some blood pressure medicines. However, large amounts of licorice must be eaten before there is an effect.

Pomegranates can have similar effect on certain statins as grapefruit.

Media Contact: cathy.frisinger@utsouthwestern.edu