More and more media reports are mentioning the potential merits of marijuana. The most recent headlines say the active ingredient in the drug cuts tumor growth in common lung cancers in half and greatly reduces the ability of the cancer to spread.

Researchers at Harvard University tested marijuana's main ingredient, delta-tetrahydrocannabinol or THC, in both lab and mouse studies and say their experiments are the first to show THC inhibits the growth of cancer.


Researchers are not certain why THC inhibits tumor growth, but it could be that the substance activates molecules that arrest the cell cycle. THC may also interfere with angiogenesis and vascularization, which promotes cancer growth.

There is a long way to go in the study of THC. Yet "the beauty of this study is that we are showing that a substance of abuse, if used prudently, may offer a new road to therapy against lung cancer," says Anju Preet, Ph.D., a researcher in the Division of Experimental Medicine.