Preliminary studies have shown that a biologically-active compound in cannabis called "9-tetrahydrocannabinol (or tetra-9-hydro-cannabinol, commonly referred to as THC) may help combat lung cancer.

In lab and mouse studies, the compound, known as THC, cut lung tumor growth in half and helped prevent the cancer from spreading, says Anju Preet, PhD, a Harvard University researcher in Boston who tested the chemical.

THC seeks out, attaches to, and activates two specific endocannabinoids that are present in high amounts on lung cancer cells, Preet says. This revs up their natural anti-inflammatory properties. Inflammation can promote the growth and spread of cancer.

Since the test animals showed signs of getting "high", getting the right dose is critical to get the therapeutic effects, without the adverse reactions.

The therapeutic potentials of cannabinoids have also been previously shown for Alzheimer's disease, osteoporosis, depression, and other types of cancers.