This is true. However my choice would be curcumin. Curcumin can also significantly reduce the dosage required but also protect the body from the toxic effects of the cancer drugs. Based on research at several US cancer research centers, curcumin may also prevent the onset of cancer and stop the growth and spreading of cancer cells. Curcumin in many cases can prevent and treat cancer better than drugs without side effects.

Grapefruit juice may let patients take lower dose of cancer drug
A study published in Clinical Cancer Research shows that taking an anti-cancer drug in combination with grapefruit juice may provide patients with the same benefits they would get from ingesting more than three times as much of the drug alone.