It’s clear that the movement to legalize medical marijuana has picked up steam in recent years, but less clear is just how potent a medicine the leafy substance can be.

While a growing number of studies have raised the tantalizing possibility that marijuana could provide a cure for cancer, the medical community at large has been hesitant to make any definitive proclamations, instead saying more study is needed.

But Dr. James W. Forsythe, an oncologist and author of the book “Stoned: The Truth About Medical Marijuana and Hemp Oil” (, is less reluctant than others to tout the use of marijuana to treat cancer.

He says the chemical THC (tetrahydrocannabinol) in marijuana appears to be effective in attacking and killing cancer cells, and the medical community and government should be more aggressive in studying and ultimately proclaiming marijuana’s potency as a cancer treatment.

“Certainly, no medicine should ever be touted as a 100 percent guaranteed cure for cancer or any other disease,” Forsythe says. “But I do think there needs to be some official acknowledgement of the ability of THC and other basic ingredients from marijuana to obliterate cancer.”

Medical marijuana is now legal in 23 states and the District of Columbia, but the federal government still lists it as a Schedule I controlled substance.

The federal government’s refusal to legalize marijuana has led to numerous conditions being placed on researchers and is deterring scientific study of the medicinal strength of cannabinoids, the natural components in the cannabis plant, according to the American Cancer Society. The society has said federal officials should examine options consistent with federal law for enabling more scientific study of marijuana.

Despite the restrictions, some research is happening. For example, studies in mice and rats have shown that cannabinoids may inhibit tumor growth by causing cell death, blocking cell growth, and blocking the development of blood vessels needed by tumors to grow, according to the National Cancer Institute at the National Institute for Health. Laboratory and animal studies have shown that cannabinoids may be able to kill cancer cells while protecting normal cells.

That hasn’t been enough to inspire scientists to declare marijuana as an answer to the fight against cancer just yet.

More often, marijuana is used to treat the symptoms of cancer, such as pain, or the side effects from chemotherapy, such as nausea and vomiting. Different strains of marijuana are considered the best for attacking different symptoms, Forsythe says.

Those strains come in dozens of varieties and they sport exotic names, such as Blueberry, Tangerine Dream and Morning Star.

Forsythe says a few examples of symptoms and the marijuana strains that can address them include:

• Nausea. Chemotherapy treatments are notorious for leaving patients nauseous. Some of the marijuana strains effective in controlling nausea are: Afghanica, OG Kush, Sour Diesel and Tangerine Dream, 
• Pain. Many strains are said to be able to control pain, including Afghanica, Alaskan Thunder, Bay 11, Blueberry, Morning Star and OG Kush.
• Stress and anxiety. Some of the stress and anxiety cancer patients feel can be alleviated with strains such as Afghanica, Blueberry, Jack Herer, Morning Star and Tangerine Dream.

“Marijuana can be used to treat a number of diseases and ailments,” Forsythe says. “Unfortunately, many people are still against the use of marijuana in any form or for any reason. It’s important to try to open their minds so that they realize the potential marijuana has to improve, and maybe even save, the lives of so many people.”

Dr. James W. Forsythe, an integrative medical oncologist, is the author of more than 20 books, including his most recent, “Stoned: The Truth About Medical Marijuana and Hemp Oil” (