On Jan. 5, 2001 -- Grapefruit juice was supposed to be good for you, but that might not always be the case. Drinking grapefruit juice together with certain medicines can increase blood levels of the drug to harmful levels, according to an editorial in the January issue of the journal Nature Medicine.
"[C]itrus fruits contain many substances other than vitamin C and some of them, such as grapefruit and Seville oranges, can be dangerous if you're taking certain medications," writes J.K. Aronson, of the university department of clinical pharmacology at Radcliffe Infirmary in Oxford, England.
Grapefruit is packed with potassium, fiber and vitamin C. The American Heart Association bestowed its heart check on the citrus fruit because of all the nutritious and healthy nutrients it contains. But grapefruit can also erode dental enamel, react dangerously with some medications and may increase the risk of developing breast cancer in post-menopausal women.
Grapefruit interacts adversely with many medications because it stops your body's CYP34A enzyme from metabolizing drugs. This means you could end up with too much medication in your system, heightening the likelihood and severity of side effects. Medications known to cause serious side effects when combined with grapefruit include calcium channel blockers, prescribed for heart-related problems; statins, prescribed for high cholesterol; some antidepressants; anti-anxiety and other psychiatric drugs; and immunosuppressants, used to prevent the body's rejection of organ transplants. For a full list of drugs that interact adversely with grapefruit, consult your doctor or pharmacist.