Grapefruit is a vitamin C-rich citrus fruit that’s low in sugar and contains micronutrients such as vitamin A, potassium, and fibre. And the pink and red varieties also contain lycopene, which is beneficial for your heart.
It’s definitely a food with a lot of health benefits. However, like some other foods, it can impact your enzyme activity. With grapefruit, the enzyme it affects can create problems with certain medications so it deserves special attention.
Enzymes and Detoxification
Certain enzymes can increase or decrease enzyme activity. In some cases, this can increase or decrease the clearance of toxins and other substances by your liver.
Sometimes it’s beneficial to support the enzyme activity with food to improve your body’s detoxification process. For instance, cruciferous vegetables can speed up the rate that the liver detoxifies certain carcinogens, toxins and products of oxidative stress.
How Grapefruit Can Impact your Meds
Grapefruit (as well as Seville oranges, limes, and pomelos) contain a compound called “furanocoumarin.” It’s this compound that inhibits (stops) the enzyme CYP3A4 from working properly.
When working properly, this enzyme breaks down and metabolizes many compounds we ingest, including dozens of medications.
When the enzyme is inhibited, this slows down the function of the enzyme. This then slows down the rate that medications are metabolized and eliminated from the body.
If you slow this process down, this leads to higher than normal levels of medications in the blood – up to 137% higher! In a sense, you are overmedicating which can cause problems and increase unwanted side effects.
- Blood pressure – causes blood pressure to drop too low
- Birth control – increases the risk of blood clots
- Immunosuppressive – often taken with rheumatoid arthritis
- Urinary tract agents
- Some over-the-counter cough medication
When the medication is taken within 24-72 hours of consuming grapefruit (yes, up to three days later!), there can be a potential side effect. And for some medications, the grapefruit effect can be serious. Serious effects include heart and muscle issues and kidney toxicity, just to name a few.
Since one glass of grapefruit juice can affect the enzyme’s function for over 24-hours, it’s advisable to stop eating the grapefruit altogether while you’re taking certain medications.
If you love eating grapefruit and are taking medications, speak with your doctor or pharmacist to see if this affects you. Some medications are not metabolized by this enzyme, and even if they are, this grapefruit effect may not pose a serious risk.
If you need to replace grapefruit in your diet, try another citrus fruit (like oranges or lemons). Or, talk with your doctor about swapping for another medication that’s not affected by grapefruit. Here are a couple of recipes that use orange and lemon juice…
Do you know someone who loves grapefruit or its juice, and is taking medications that have the grapefruit effect? Share this post to let them know that they should double-check with their doctor or pharmacist before enjoying this awesome fruit.