It is believed that drinking coffee and consuming grapefruit together helps a person stay awake for longer, because the substances in this citrus fruit slow down the breakdown of caffeine in the body.
Gastroenterologists explain the extent of the evidence supporting this theory and the risks that this effect may cause.
According to gastroenterologist Dr. Ekaterina Kashukh, grapefruit contains two biologically active substances, naringin and furanocoumarin, which affect liver enzymes. Specifically, they inhibit the CYP1A2 enzyme, which is responsible for breaking down most of the caffeine in the body. Theoretically, this could lead to caffeine levels remaining in the bloodstream for a longer period, but scientific data on this topic is still conflicting.
The doctor confirms that current research does not allow us to confidently say that there is a significant increase in the effect of energy, because the rate of metabolism depends on individual characteristics, age, and health status.
She says: "It should be understood that even if grapefruit affects the rate at which caffeine is metabolized, this does not necessarily mean that it will make a person more alert or energetic."
Dr. Yevgeny Belousov points out that, in addition, the slowed metabolism of caffeine can lead to adverse reactions, especially in sensitive individuals. These effects include increased anxiety, elevated heart rate, increased blood pressure, hand tremors, and sleep disturbances. Therefore, experts advise against consuming these two products together if you have liver disease, high blood pressure, or an irregular heartbeat.
He says: "Combining coffee and grapefruit may increase side effects in sensitive individuals, including anxiety, palpitations, and insomnia. When more than 200 mg of caffeine is consumed at one time (roughly equivalent to two cups of strong coffee), the risk of side effects increases."
According to him, the reaction of grapefruit compounds with enzymes may last from one to three days. He also advises against caffeine consumption for children under 12 years old, as it may cause sleep disturbances and anxiety.
In addition, people taking certain medications should be especially careful, as grapefruit can alter the metabolism of statins, antiarrhythmics, and high blood pressure medications. For example, when taking losartan, it may reduce the effectiveness of the treatment by preventing the drug from being converted to its active form.
Dr. Kashoukh points out that experts advise consulting a doctor beforehand if taking medication regularly.
She says: "We must always remember not the potential effect of grapefruit on caffeine, but the potential for it to interact with medications."
