WebMD link Quote:
Heavy Marijuana Use Doesn't Damage Brain
Analysis of Studies Finds Little Effect From Long-Term Use
By Sid Kirchheimer
WebMD Medical NewsJuly 1, 2003 -- Long-term and even daily marijuana use doesn't appear to cause permanent brain damage, adding to evidence that it can be a safe and effective treatment for a wide range of diseases, say researchers.
The researchers found only a "very small" impairment in memory and learning among long-term marijuana users. Otherwise, scores on thinking tests were similar to those who don't smoke marijuana, according to a new analysis of 15 previous studies.
In those studies, some 700 regular marijuana users were compared with 484 non-users on various aspects of brain function -- including reaction time, language and motor skills, reasoning ability, memory, and the ability to learn new information.
Surprising Finding
"We were somewhat surprised by our finding, especially since there's been a controversy for some years on whether long-term cannabis use causes brain damage," says lead researcher and psychiatrist Igor Grant, MD.
"I suppose we expected to see some differences in people who were heavy users, but in fact the differences were very minimal."
The marijuana users in those 15 studies -- which lasted between three months to more than 13 years -- had smoked marijuana several times a week or month or daily. Still, researchers say impairments were less than what is typically found from using alcohol or other drugs.
"All study participants were adults," says Grant, professor of psychiatry and director of the Center for Medicinal Cannabis Research Center at the University of California, San Diego School of Medicine.
"However, there might be a different set of circumstances to a 12-year-old whose nervous system is still developing."
About.com link with other links Quote:
Brain Damage and Alcohol Consumption
Brain damage is a common and potentially severe consequence of long-term, heavy alcohol consumption. Even mild-to-moderate drinking can adversely affect cognitive functioning.
NIAAA linkQuote:
ALCOHOL’S DAMAGING EFFECTS ON THE BRAIN
Difficulty walking, blurred vision, slurred speech, slowed reaction times, impaired memory: Clearly, alcohol affects the brain. Some of these impairments are detectable after only one or two drinks and quickly resolve when drinking stops. On the other hand, a person who drinks heavily over a long period of time may have brain deficits that persist well after he or she achieves sobriety. Exactly how alcohol affects the brain and the likelihood of reversing the impact of heavy drinking on the brain remain hot topics in alcohol research today.
CannabisCulture link Quote:
Marijuana protects your brain by Dana Larsen (01 Jan, 1999)
Studies reveal that marijuana protects against brain damage from stroke, heart attacks, and nerve gas.
The US National Institute of Health has found that chemicals in cannabis can reduce the extent of damage during a stroke, at least in rats.
Experiments with rat nerve cells, and then with actual rats, suggest that THC and cannabidiol, both compounds found in marijuana, can protect cells by acting as antioxidants, and could be useful in the treatment and prevention of stroke, heart attacks, and neurodegenerative diseases.
Researchers are investigating how cannabidiol and other antioxidants can reduce the severity of damage from "ischaemic strokes", in which blood vessels in the brain become blocked.
During ischaemic strokes, which make up 80% of all strokes, free radicals are released into the bloodstream. These harmful molecules are believed to cause stroke damage, such as paralysis and loss of speech and vision. Cannabidiol has potent anti-oxidant and anti-inflammatory properties, so it can neutralize free radicals and limit their damage.
Meanwhile, an Israeli pharmaceutical company called Pharmos is conducting human clinical trials using a synthetic, injectable version of cannabidiol, which they have dubbed Dexanabinol.
Dexanabinol's creator is Professor Raphael Mechoulam of Hebrew University in Jerusalem, who discovered THC in 1964, and has been studying cannabis for over thirty years.
Dr William Beaver, who chaired a panel assembled last year by the US National Institute of Health to review the medical uses of marijuana, called Dexanabinol "the most medically significant use ever made of marijuana."
The human clinical tests began in 1996 with 67 patients in Israel's neurotrauma centres. About 1000 patients will be involved in the next phase, at a cost of $15 million over two years. According to US medical investment analysts, Dexanabinol showed no serious side effects when administered to healthy volunteers.
Aside from the five million people worldwide who suffer a stroke or head trauma each year, there's another huge market for Dexanabinol, the US Army. US military tests on rats have shown that those exposed to Dexanabinol were 70% less likely to suffer epileptic seizures or brain damage after being exposed to sarin and other nerve gases. Dexanabinol is effective as both a preventative measure and as an antidote.
The military's greatest concern seems to be whether Dexanabinol possesses the same psychoactive and enlightening properties as THC and some other cannabinoids. Although THC and cannabidiol both provided equal defense against cell damage, cannabidiol doesn't have significant psychoactive effects.
Of course, the obvious corollary to this is that if synthetic Dexanabinol can prevent brain damage, then organic marijuana does so as well. So the next time grandpa has a stroke, try and get him to take a few bong-hits before the ambulance arrives. Better yet, give him a hash brownie each evening before he has that stroke. You might just save his life.
WebMD link Quote:
Cannabis Relieves Multiple Sclerosis Pain
Painkiller May Also Provide Better Mental Health With Few Side Effects
By Jeanie Lerche Davis
WebMD Medical NewsJuly 15, 2004 -- An extract from cannabis can reduce pain from multiple sclerosis, a new study shows.
This new finding adds to growing evidence of the painkilling potential of cannabis. Animal research has shown that cannabinoids can decrease pain sensation caused by inflammation, damaged nerves, and cancer. Also, studies have pointed to cannabinoids as helping control pain from muscle spasticity -- muscle stiffness and limb rigidity -- in patients with multiple sclerosis (MS).
There are many different types of pain that a person with multiple sclerosis sufferers. The list includes pain caused by plaque lesions seen in the brains of people with multiple sclerosis called central pain. These lesions may cause pain by altering chemicals which transmit pain signals or they may cause changes in the way signals are transmitted to pain regions in the brain.
Can cannabis relieve central pain in multiple sclerosis patients with lesions? This is the first study examining that question -- and it shows a "modest but relevant" reduction in pain, writes researcher Kristina B. Svendsen, MD, with the Danish Pain Research Center and department of neurology at Aarhus University Hospital in Denmark. Her study appears in this week's issue of the British Medical Journal.
I guess I'm one of the "dumbed down version of their former selves" you're referring to, since I've smoked pot off and on since age 15. That's 35 years, with one period of 8 years abstinence, and greatly reduced, occasional use the past 6 years.