Did Smoking Pot Mess Up Your Brain?
Actually, research suggests that the chemicals in marijuana might protect against Alzheimer’s.
By CHRIS GOLDSTEIN and DEBBIE GALANT
At some point in the 1960's or 70's a friend passed you a joint. You felt giggly, listened to some music, and started talking about crazy things like the meaning of life. Maybe you’ve smoked marijuana regularly the past 40 years. Or maybe you stopped — but tried it recently on a trip to Denver. You’re not alone; more than 100 million Americans have tried cannabis.
But now, maybe you’ve found yourself misplacing your keys one time too many. Or worse yet, your car. Maybe you just can’t think of that really handsome actor who reminds you of that other guy. (George Clooney, Cary Grant). Twenty years ago, you might have laughed off such a lapse by saying, “I guess smoking pot killed too many brain cells.”
But now, having just witnessed one of your parents struggle miserably with Alzheimer’s, it suddenly occurs to you: did smoking pot damage my brain?
Actually, scientific evidence is mounting that cannabis and chemical components in the plant called cannabinoids may have potential to delay or prevent the onset Alzheimer’s disease.
The mechanism of Alzheimer’s is well known: amyloid plaques build in the brain, neurons die. Yet after more than a century of scientific research, the cause is still unclear. Researchers at the Stanford University School of Medicine, however, published a study last year that posited a new theory. According to this research, Alzheimer’s begins when a protein called A-beta blocks the brain’s own endocannabinoid chemicals — the body’s internal marijuana.
Meanwhile, researchers in Spain, in experiments with laboratory mice, found that cannabis compounds actually “preserved memory” while “reducing learning impairment” and changed the composition of the amyloid plaque. Another study, published last year in the Journal of Alzheimer’s Disease, conducted not in animals but in petri dishes, was extremely optimistic: “These sets of data strongly suggest that THC could be a potential therapeutic treatment option for Alzheimer’s disease.” There are at least a half dozen similar studies, some even point toward neurogenisis — stimulating the growth of new brain cells.
To be sure, nobody—ourselves included—is telling people that they should go out and smoke as much weed as possible to ward off dementia—or try to fix it. The effect of marijuana on memory and brain function is complicated. And controversial. Just Google “does marijuana kill brain cells” to see how many opinions there are on this topic. The answers, it seems, stem as much from politics as from science.
The truth is, it’s complicated. In this National Geographic video, we see a London graduate student getting tested in a research lab. After inhaling marijuana vapor, he flunks a test to recall a news story—but aces a challenge to think of as many words as he can that start with the letter “G.” The conclusion: marijuana might actually prevent you from forming new memories, but free up your brain to make connections between concepts that are already there.
Gary Wenk, a professor of psychology and neuroscience at the Ohio State University and the author of Your Brain on Food, is part of what we he sees as a very small club of marijuana researchers in the United States. “Trying to do cannabinoid research in the United States has been fraught with problems,” he says. The government doesn't want to fund it, the press can be alarmist and the rats to do research on cost $1,000 apiece. Still, Wenk has done rat studies on cannabinoids and cognitive function and he’s an optimist about the potential for marijuana or its components to prevent dementia.
That’s because cannabinoids are anti-inflammatory, and it turns out that reducing inflammation in the brain is a good way to protect it. Of course, anti-inflammatory properties can be found in many things besides marijuana. Take curcumin, an ingredient in curry. “People in India rarely get Alzheimer’s disease,” he says. Same with standard inflammatory drugs. “Patients with arthritis rarely get Alzheimer’s disease.” Likewise, he says, at least anecdotally, it appears that people who used marijuana regularly in the 1960's have less dementia than their abstaining peers.
Heartbreakingly, Wenk receives emails from spouses of Alzheimer’s several times a week, wanting to know whether marijuana—or anything—can help their loved ones.
“My view is that it’s simply too late,” he says. “There’s every reason to believe that cannabinoids may be protective, but once the pathology’s there, it’s too late.”
A side thought. Anybody who’s gotten high on pot — at least anyone with a cerebral proclivity—knows the feeling of watching dozens of brilliant insights pop up like so many thought bubbles, and the accompanying feeling of wanting to hold onto these insights for inspection the next morning.
Carl Sagan, identified after his death as a longtime marijuana user and Mr. X, the anonymous contributor to the book Marihuana Reconsidered by Dr. Lester Grinspoon, wrote about exactly that.
There is a myth about such highs: the user has an illusion of great insight, but it does not survive scrutiny in the morning. I am convinced that this is an error, and that the devastating insights achieved when high are real insights; the main problem is putting these insights in a form acceptable to the quite different self that we are when we’re down the next day. Some of the hardest work I’ve ever done has been to put such insights down on tape or in writing. The problem is that ten even more interesting ideas or images have to be lost in the effort of recording one. It is easy to understand why someone might think it’s a waste of effort going to all that trouble to set the thought down, a kind of intrusion of the Protestant Ethic. But since I live almost all my life down I’ve made the effort — successfully, I think. Incidentally, I find that reasonably good insights can be remembered the next day, but only if some effort has been made to set them down another way. If I write the insight down or tell it to someone, then I can remember it with no assistance the following morning; but if I merely say to myself that I must make an effort to remember, I never do.
Sagan’s effort to clutch onto his marijuana epiphanies parallels, in an odd way, the efforts described by longtime journalist Greg O’Brien, who was diagnosed with early-onset Alzheimer’s at 59 and yet has managed to report back from the world of short-term memory loss in an astonishing memoir, On Pluto. His reporting from within the war zone that is Alzheimer’s is a stunning tribute to both intellect and perseverance. And to do it, he employed one of the tricks pot smokers may be familiar with.
I rely on copious notes and my trusty iPhone with endless email reminders. I am startled when my inbox tells me I have 40 new emails, then I realize that 35 of them are from me.”
Is it possible that if Sagan, who died at 62, had lived long enough to develop Alzheimer’s, he might have been better prepared to navigate its rocky shoals? Or to put it more broadly…
If a marijuana high does resemble, in some unsettling way, early-onset Alzheimer’s, then could getting high—and learning how to grasp the thought bubbles that arise and pop so quickly—be a kind of brain training for possible dementia down the road?
My Grandma Pat never lost her ability to flash a genuine smile. She could no longer walk, had trouble speaking, remembering her family and coordinating any movement. Yet her bright blue eyes shone on without fading. Her Irish sense of humor would pull at the corners of her eyes and lips in reaction to us or her constant internal wit.
Her doctors tried dozens of drugs and treatments over the course of a decade to mitigate the progression of Alzheimer’s Disease. There were pills for memory loss and brain function, painkillers and then powerful anti-depressants like Zoloft. They stopped her from having vodka martinis and put her on special diets. When Grandma Pat passed away in 2011, peacefully in hospice care with my mom and me holding her hands, I wondered if we had left something out that may have helped. Certainly this story by a medical marijuana evangelist who treated his other mother suggests that marijuana might, if not cure Alzheimer’s, then at least make it more bearable—both for patients and their caretakers.
I wish I had shared a joint with my grandmother. It may not have restored her memory. But it might have been fun for us both.
Chris Goldstein is associate editor of Freedom Leaf magazine and co-chair of PhillyNorml. He also writes the Philly420 column for Philly.com.
Debbie Galant is the publisher and editor of Midcentury/Modern, which plans to write more on marijuana and baby boomers.
