Why does grapefruit juice have an impact on drugs?

Eating grapefruit or drinking grapefruit juice can cause interactions with some medications - but what kind of affect does grapefruit have?

By James Lloyd

Asked by: Len Baker, Leicester

Grapefruit juice is widely regarded as a healthy, all-natural drink rich in vitamins C and A. But researchers have discovered that grapefruit juice affects the action of a human enzyme called CYP3A4, boosting the power of some drugs to potentially dangerous levels. Over 40 drugs are now known to be affected, including some used for treating blood pressure.

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James Lloyd

Staff writer, BBC Science Focus

James is staff writer at BBC Science Focus magazine. He especially enjoys writing about wellbeing and psychology. In his spare time, he likes eating quiche.