For decades, anti-drug campaigns have portrayed cannabis as a risky substance that not only opens the door to abusing harder drugs, but also causes a long list of harmful effects—including permanent damage to memory and cognition. More recently, though, numerous studies from around the world are revealing that far from destroying brain cells, compounds in cannabis are both uniquely able to protect them and support the growth of new ones.
Now, this new research shows that the potent neuroprotective properties of tetrahydrocannabinol (THC) and other cannabis compounds may offer new hope for treating not only brain injury and neurological disorders such as Parkinson’s disease and multiple sclerosis, but also Alzheimer’s and aggressive cancers in the brain and body.
Neuroprotectants are agents that help to reduce damage to the brain and nervous system caused by injury, exposure to toxins, or inflammatory processes or disease states in the body. These agents also encourage the growth and development of new neurons. Neuroprotectants take many forms, ranging from vitamins and synthetic drugs to herbs and natural substances such as marine algae.
Now, a variety of studies indicate that cannabis may be among the most powerful of these, thanks to its action on the body’s cannabinoid receptors and its own anti-inflammatory and antioxidant properties.
Neurological damage can come from direct injury, such as in head trauma or a stroke. It can be caused by exposure to toxic substances, including alcohol and nicotine, or by various processes that damage the protective sheaths surrounding nerves or the nerve cells themselves.
But the cannabis compounds cannabidiol (CBD) and THC can protect against many causes of nerve damage and help repair damage once it happens by preventing inflammation; stimulating the growth of new, healthy cells; and encouraging the death of malignant ones.
The endocannabinoid system (ECS) is an extensive network of receptors primed to respond both to cannabinoid substances naturally produced by the body and to cannabinoids from outside sources, most notably cannabis itself. The ECS is directly or indirectly responsible for supporting a variety of systems and processes in the brain and many organs and tissues; this helps explain why cannabis can have such a wide range of neuroprotective effects.
The brain can be injured in a variety of ways. Stroke is caused either by a burst blood vessel or a blockage in a blood vessel, so that neurons controlling various functions such as memory or coordination are damaged and die. Traumatic brain injury is caused by an impact to the head, which can lead to brain swelling and bleeding—and the subsequent damage and death of cells in the area.
In a variety of studies, cannabis has been shown to reduce the damage to brain cells caused by these kinds of events. But cannabis is also capable of encouraging the growth of new brain cells—a process called neurogenesis that until recently seemed impossible under any circumstances.
Neurotoxins—substances capable of causing neurological damage—come in a variety of forms, such as industrial solvents, pesticides, certain kinds of drugs as well as the more familiar alcohol and nicotine. These substances can damage or kill brain cells that govern memory, movement and other processes. Cannabis, particularly the compound CBD, appears to be able to protect nerve cells against inflammation caused by toxic substances, particularly the brain damage that can accompany chronic alcohol abuse.
Cannabis shows promise in treating the symptoms of serious neurological disorders such as Parkinson’s disease, multiple sclerosis and amyotropic lateral sclerosis, or ALS (also known as Lou Gehrig’s disease). These and other neurological problems typically involve inflammatory processes that disrupt the regulation of neurotransmitters in the brain and cause problems with movement and coordination.
Cannabis compounds, especially CBD, have both anti-inflammatory and antioxidant properties that can help regulate the production of dopamine and other neurotransmitters, and reduce the severity of symptoms related to these kinds of disorders.
Much of the research on the neuroprotective properties of cannabis has focused on CBD, which is non-psychoactive and strongly associated with supporting immune system functions and fighting inflammation. But psychoactive THC from the natural cannabis plant also has a role to play in protecting vulnerable cells—and, perhaps, in fighting some of the most aggressive and often untreatable cancers of the brain and other parts of the body.
Glioma is a fast-growing, aggressive and mostly fatal kind of cancer that forms in the glial cells of the brain and, sometimes, the spinal cord. Because glioma is frequently inoperable, treatment options can be limited.
But recent studies on the effects of cannabis on glioblastoma cell lines reveals that THC not only decreased the proliferation of malignant glial cells, it also triggered a process called apoptosis, or programmed cell death. In this process, THC was able to selectively target only the malignant cells, while ignoring the healthy ones. These preliminary findings support other research showing that cannabis may be able to target tumor development in the lungs, breast and other areas of the body.
One of the most promising areas for research on the neuroprotective properties of cannabis comes in the fight against Alzheimer’s disease—a progressive form of dementia believed to be caused by the buildup of proteins called beta amyloid plaque in the brain. A recent study sponsored by the Salk Institute reveals that a different process may be at work—and cannabis is uniquely positioned to affect it.
The Salk study found that inflammation caused by plaque occurs in cells themselves, and cannabinoid-like compounds manufactured by those cells may prevent them from damage and death. Because these THC-like compounds can exert a protective effect, cannabis, especially with a significant THC content, may be able to protect brain cells from inflammation and damage related to plaque. And because cannabis appears to help promote the growth of new neurons, it could be helpful in slowing the development of Alzheimer’s disease once it develops.
And the effect of cannabis on memory? In sharp contrast to the rhetoric of the old (and not so old) anti-drug campaigns, this effect appear to be minimal and transitory—if they’re felt at all. A number of studies reveal no lasting impact on memory and cognition from consuming cannabis, especially for therapeutic purposes. Research continues to reveal new ways that cannabis in all its forms can be a potent neuroprotectant with the power to support, not harm, nerves and cells throughout the body and brain.
Photo credit: Daniel Hjalmarsson