Lisa Nelson RD #8: Please clear up the confusion about grapefruit and medication! Is it safe for individuals taking medication for heart disease, such as Lipitor, to eat grapefruit or drink grapefruit juice? When is grapefruit not allowed?
Dr. Shelby-Lane: I am including information that may help answer your question about grapefruit and a variety of nutritionals that affect statin drugs for the lowering of cholesterol.
Zocor (Simvastatin), for example, is a Statin drug, used to lower high cholesterol levels, and also known as HMG-CoA reductase inhibitor. Zocor may affect the absorption or utilization of vitamins E and coenzyme Q10. Tests showed the average concentration of coenzyme Q10 in blood plasma decreased by approximately 50% after statins were used for 30 days. Supplementation is considered beneficial.
Grapefruit and grapefruit juice may increase the effects of HMG-CoA reductase inhibitors and should not be consumed at the same time. It is suggested that these medications be taken with water. Grapefruit contains substances that may inhibit the body's ability to break down statin drugs increasing the toxicity of the drug. Muscle pain, tenderness, or muscle weakness may be a result. If you begin to notice these symptoms, contact your doctor.
Niacin is the form of vitamin B3 used to lower cholesterol. Large amounts of niacin taken with a statin drug may cause serious muscle disorders (myopathy). Reasonable levels of niacin combined with statin drugs have been shown to enhance the cholesterol lowering effect. For proper dosage, consult your physician before taking niacin.
Pomegranate juice has been shown to inhibit the same enzyme inhibited by grapefruit juice. This may cause reactions similar to grapefruit juice when it is used with statin drug treatments.
A study of 37 people with high cholesterol treated with diet and statin drugs found vitamin A increased in the blood over two years of therapy. People taking statin drugs and vitamin A supplements should have blood levels of vitamin A monitored.
Magnesium and aluminum containing antacids were reported to interfere with statin drug absorption. To avoid this interaction, take statin drugs two hours before or after any aluminum/magnesium containing antacids. Some magnesium supplements such as magnesium hydroxide are also antacids.
It should be noted that doctors often recommend supplementing with 100 mg of coenzyme Q10 per day for maintaining healthy levels. However, those on statin drugs may have a greater need for a higher dose. It further should be noted that the symptoms associated with the combination of grapefruit juice and statin drugs (muscle weakness and discomfort) are commonly reported as symptoms associated with CoQ10 depletions. Supplementation with coenzyme Q10 is strongly recommended.
The herbs Artichoke plant, Garlic and Plantain may decrease blood cholesterol levels, and therefore enhance the effects of Zocor. Consult with your pharmacist or physician before taking them.