Specific molecules occurring naturally in grapefruit juice may increase the level of statins in a person’s blood, which can ‘exacerbate’ their effects.
Drinking a small glass of grapefruit juice may not have severe effects.
However, a person taking statins should always speak with a healthcare provider before consuming grapefruit or grapefruit juice.
On rare occasions, however, grapefruit and grapefruit juice can interact with statins, leading to dangerous side effects.
The study found that compounds in grapefruit prevent the body from metabolising statins normally, which increases their concentration in a person’s blood.
Usually, when a person consumes statins without grapefruit juice, the enzyme CYP3A breaks them down within the intestines and liver.
This process lowers the amount of statins reaching the bloodstream.
However, furanocoumarins – compounds that exist naturally in grapefruit – kill this enzyme and therefore prevent it from breaking down statins. Therefore, the body absorbs more statins than normal from the gut into the bloodstream – leading to potentially fatal consequences.
According to the research team, more than 85 drugs may interact with these compounds in grapefruit – not just statins.
Furthermore, other citrus fruits may contain compounds with similar interactions. These include:
- Seville oranges
According to the NHS, a person taking statins can seek advice from their GP about all the citrus fruits to avoid if taking statins.
Not all statin medications are the same in terms of their interaction with grapefruit.
On the other hand, one separate study revealed that taking grapefruit juice with certain statins may actually have beneficial effects, reducing levels of LDL cholesterol by up to around six percent.
Because of this, some scientists argue that healthcare providers should not prohibit people from taking grapefruit in moderation with certain statins.
Someone taking some statins may only start to see harmful effects if they drink one quart (946 milliliters) or more of grapefruit juice.
Eating grapefruit is less risky because the typical serving size – about half a grapefruit – contains less than a typical glass of juice a person might have with breakfast.