A new study suggests that drinking grapefruit juice may help increase the effect of anti-cancer drug more than three times of the medication.

A team of researchers from the University of Chicago Medicine said that the combination of grapefruit juice with a low dose of an anti-cancer drug will have no impact on side effects from the anti-cancer drug.

Sirolimus, also known as rapamycin, is a drug which helps in preventing the rejection of organ transplantation. The drug is found to have anti-cancer properties although it has not been used to treat cancer until now.

"It was clearly shown to have anti-cancer effects and anti-neoplastic effects, but it hadn't been developed for cancer extensively because the patent ran out. There wasn't a lot of commercial interest to develop sirolimus, so it sort of was pushed aside for a while. Eventually, sirolimus was indeed approved, but for people who got organ transplants to prevent rejection," Dr Ezra Cohen, a cancer specialist at the University of Chicago Medicine and the study's lead author, told FoxNews.

Researchers have now found that the anti-cancer benefits increase when sirolimus is consumed with the grapefruit juice. When siromulus is consumed, only 14 percent of the total amount of drug is actually absorbed from a given dose.

For their study, researchers tested 138 patients with incurable cancer. They were split into three groups - one group who received only sirolimus, sirolimus and grapefruit juice, and sirolimus and ketoconazole. Ketoconazole is a drug that slows down drug metabolism.

Patients who received sirolimus had to consume 90 mg of the dose per week to get the anti-cancer effects. But when they cosumed the drug above 45 mg, the patients had side effects including nausea and diarrhea. But for the other two groups, patients were needed to take less dose of the drug.

Experts revealed that those patients who drank eight ounces of grapefruit juice per day increased their sirolimus levels by 350 percent. Those who consumed ketoconazole increased the sirolimus levels by 500 percent. Although the researchers found that the effect of ketoconazole was more effective, they recommended drinking the natural grapefruit juice as it is non-toxic.

The findings of the study have been published in ClinicalCancer Research.