A recent study from scientists at La Jolla’s Scripps Research Institute suggests that the active ingredient in marijuana, tetrahydrocannabinol, may someday prove to be an effective treatment for Alzheimer’s disease, a debilitating degenerative memory disorder.
The dementia caused by Alzheimer’s disease is debilitating to both memory and language capacity, currently affecting approximately 4.5 million Americans. Five percent of the population over 65 years old, and more than half the population over 85 now has the disease, according to the National Institute on Aging. In addition, the Alzheimer’s Association estimates that the number of affected Americans could increase to 16 million by 2050.
There is no cure for Alzheimer’s, and the causes remain a mystery. But help may be on the way in the form of THC. Alzheimer’s patients all show unusually high levels of a key enzyme, acetylcholinesterase (AChE), which forms a kind of plaque in the brain. According to the study, dopenzil and tacrine, two leading drugs in the treatment of Alzheimer’s patients, show only 22 percent and 7 percent effectiveness in inhibition of the enzyme, respectively. However, the study suggests that THC has shown significant effectiveness at stopping the effect on aggregation — blocking it “completely.” But the study, which was supported by the National Institutes of Health, is still in its infancy.
THC “may provide an improved therapeutic for Alzheimer’s disease” that would treat “both the symptoms and progression” of the disease, the study stated.
Dr. Kim Janda, a chemist at SRI, a member of the Skaggs Institute for Chemical Biology and the author of the study, declined to comment, and said that the study “has been badly politicized and taken out of context by the media.”
However, in an SRI press release, Janda stressed the significance of the new findings while also denouncing illegal drug use.
“While we are certainly not advocating the use of illegal drugs, these findings offer convincing evidence that THC possesses remarkable inhibitory qualities, especially when compared to AChE inhibitors currently available to patients,” Janda stated.
Other authors of the study, titled “A Molecular Link Between the Active Component of Marijuana and Alzheimer’s Disease Pathology,” include SRI researchers Lisa M. Eubanks, Claude J. Rogers and Tobin J. Dickerson.
According to the press release, any new treatment that could halt or even slow the progression of the disease would have a major impact on the quality of life for patients, including reducing the staggering costs associated with the disease. A survey from the National Center for Health Statistics stated that half of all nursing home residents have the disorder, and the NIA estimated that Alzheimer’s-related treatment costs are $100 billion annually.
Although skeptics have historically questioned marijuana’s potential as a viable medical drug, the study’s results strongly suggest a realistic possibility of a new treatment for the mysterious disease. Marijuana is currently labeled as a “schedule-one” drug by the U.S. Drug Enforcement Administration — the most restricted category — meaning that even under medical supervision, it is unsafe to use. However, many states, including California, have legalized the medical use of marijuana.
Currently, there are four FDA-approved treatments for Alzheimer’s that work by inhibiting the active site of AChE, and marijuana’s potential has given scientists at SRI the desire to advance their research.
“Our results are conclusive enough to warrant further investigation,” Janda stated in a press release.
Although the research has demonstrated that THC can prevent the mental decline associated with the disease, marijuana is not necessarily good for the mind. Other studies have suggested that heavy marijuana use can impair memory and users’ ability to pay attention to more than one thing at a time.
