Lester Grinspoon, associate professor emeritus of psychiatry at Harvard Medical School, called on the National Football League last week to sponsor research on the medical use of cannabis.

In an open letter to the institution, Grinspoon highlighted the difference between two compounds found in cannabis, cannabidiol (CBD) and tetrahydrocannabinol (THC), which he argued is pivotal in resolving the controversy surrounding the substances.

In particular, he suggested that CBD could potentially provide significant protection for the brain against the damage of repetitive concussions, which are common in professional football games.

“In the past, people tended to cultivate the strains of cannabis which were rich in THC, which was the substance that got you high,” Grinspoon said. “However, as THC went up, CBD, which we are interested in because of its medical properties, actually went down.”

According to Grinspoon, a strain of cannabis with a high CBD to THC ratio could be highly desirable for football players who seek protection against concussions.

“There is no question that cannabidiol is a neuroprotector.”

He also stressed that CBD had no psychoactive effects.

“[CBD] just doesn’t get you high,” he said.

Grinspoon suggested that the lack of investment from pharmaceutical companies is due to the fact that plants and their natural components cannot be patented. In the public sector, it is also difficult to get funding from the government due to the Comprehensive Drug Abuse Prevention and Control Act of 1970.

“The [funding sources] don’t exist for what I am proposing,” said Grinspoon in email.

In his open letter, Grinspoon argued that funding the research into cannabinoids would not only be “a great public service,” but would also be in the self-interest of the NFL. He claimed that the proposed protective effects of CBD against concussions could reduce the amount of compensation the NFL would have to provide for former players who have brain damage.

In order for the Food and Drug Administration to authorize the sale of a drug, it would require animal studies followed by “a number of controlled studies on a group of human beings,” to demonstrate its safety and efficacy.

“[We need] millions of dollars.” Grinspoon estimated when asked about the scale of funding he had in mind. “[The NFL] must go beyond simply following the medicine, and help lead the way.”