Already, patients in several countries use medical cannabis to ease the pain, nausea, and other severe side effects of cancer treatment.
Yet, what if the plant just might be the newest cancer-fighting drug to hit the markets?
While no large-scale human studies have been completed, new research suggests that the non-intoxicating cannabis compound, cannabidiol (CBD), may be useful for actually treating cancer, not just easing symptoms.
A new animal study has found that cancer-laden rodents have three times the survival rate when given CBD along with their chemotherapy.
CBD + Chemo prolongs life in mice with pancreatic cancer
A study published in Oncogene in July of 2018 presented some striking experimental evidence regarding CBD and chemotherapy.
Mice with pancreatic cancer survived nearly three times longer when their chemotherapy treatment was combined with the cannabis-derived compound.
CBD is a non-intoxicating component of the cannabis plant and the molecule has been making waves in the nutritional supplement world.
Researchers coadministered CBD and gemcitabine (GEM), one of the most common chemotherapy drugs used to used to treat pancreatic cancer.
Mice treated with this dynamic duo not only lived three times as long, but the combination blocked the proliferation of tumor cells more than just with chemotherapy alone.
Yet, rodents certainly aren’t humans. While this research is promising, the next step is figuring out whether or not CBD is as effective in humans.
“Our data indicate that [a] combination of CBD and GEM, both currently approved for medical use [in the UK],” begin the study authors, “might be tested in clinical trials as novel promising treatments to improve [the outcome in pancreatic cancer].”
While adult-use cannabis is still illegal in the United Kingdom, the British Medicines and Healthcare Products Regulatory Agency officially allowed CBD to be submitted for approval as a medical product and nutritional supplement back in 2016.
This legal move allows researchers to cultivate the cannabis plant for scientific purposes and allows them to perform human trials on CBD medicines.
In the United States, the Schedule I status of the herb means that a limited number of researchers are allowed adequate access to cannabis, let alone granted permission to sufficiently study the plant for new drug developments.
Does CBD really fight cancer?
If this experimental evidence is worth the hype, cancer patients may be among those harmed by these barriers to medical research.
While this new study is undeniably exciting, it is now one of many experimental projects that have shown that compounds in the cannabis plant appear to have significant anti-cancer potential.
To be transparent from the get-go, there have been no large-scale or substantial human trials regarding any cannabis compound in the treatment of cancer.
Yet, that does not mean that clinical trials are not on their way.
Already, scientists have had success with combo THC, CBD, and chemotherapy treatments in phase 2 clinical trials in human patients with glioma, a brain cancer that is particularly difficult to treat.
Unlike many traditional chemotherapy drugs, CBD and THC are small enough to pass through the blood-brain barrier, a protective network of blood cells that prevents the exposure of toxins and pathogens in the brain.
Pancreatic cancer is similarly difficult to treat, with around five percent of patients surviving five years post-treatment.
“The life expectancy for pancreatic cancer patients has seen no substantial changes in the last 40 years,” write the Oncogene study authors. “Very few and mostly just palliative treatments are available.”
While it is unlikely that patients will be able to access cannabis-based drugs along with their chemotherapy anytime soon, the growing wealth of developments in cannabis and cancer research is remarkable.
The glioma and pancreatic cancer studies cited thus far are among the few pieces of research that suggest that cannabis compounds may prolong the lives of cancer patients.
Yet, multiple compounds in the cannabis plant have demonstrated anti-cancer potential, including CBD. According to a 2013 review published in the British Journal of Pharmacology, CBD has shown anti-cancer effects in breast, glioma, leukemia, lung, colon, and thyroid cancers.
Here are very brief summaries of how CBD might work in three of the most common types of cancer:
1. Breast cancer
Amazingly, one potential reason why CBD was effective in these experiments is due to the cannabinoid’s ability to regulate genes involved in cell proliferation.
As a 2011 study published in the journal Breast Cancer Research and Treatment found, the cannabis compound successfully reduced the expression of the ID-1 gene, a gene that is dramatically over-expressed in aggressive forms of breast cancer.
Theory has it, altering gene expression may decrease the growth and spread of tumor cells.
Yet, gene expression isn’t the only reason why CBD may have an effect on breast cancer. The cannabis molecule has remarkably triggered the death of tumor cells in laboratory experiments, according to a 2011 paper published in Molecular Cancer Therapeutics.
While killing tumor cells in a petri dish is a long way from reducing cancer in a human body, this early research provides a worthy cause for continued investigation.
2. Lung cancer
Lung cancer is among the most common types of cancer. In fact, when the numbers were crunched back in 2015, the disease is estimated to claim over 1.69 million lives around the globe.
While cannabis is perhaps most often thought of as a smoked recreational treat, many may find it surprising that CBD and other cannabis compounds seem to exert anti-tumor effects in lung cancer.
In early laboratory tests of cultured lung cancer cells, the hemp molecule successfully decreased the invasiveness of lung cancer tissues as well as prevented the cancer cells from breaking away from their original cluster, which would allow them to spread to other parts of the body.
Researchers are a long way from testing CBD medicines in humans, but some of the anti-cancer potentials of CBD have also been found in rats.
For example, one study published in Biochemical Pharmacology found that the hemp compound also reduced the invasiveness and spread of lung cancer cells in mice.
3. Colon cancer
Like breast and lung cancer, colon cancer is one of the most common cancers in Western countries. It is also yet another cancer that may respond well to CBD.
For example, in a 2014 study published in Phytomedicine, researchers found that treating rodent models with a cannabis extract high in CBD successfully reduced the proliferation of colon cancer.
Amazingly, the study found that CBD used as a whole plant extract performed better than isolated CBD alone in terms of reducing the growth of polyps and tumors in test animals.
Unfortunately, these preclinical tests and trials are a long shot when trying to figure out just when and how CBD might be beneficial for cancer.
Yet, these early studies are certainly promising and mark the beginning of what seems to be turning into a long exploration of CBD for cancer.
Ed. Note: Parkinson’s is yet another disease that people are subjectively saying can be helped with marijuana. Is it true? It needs study. In the meantime, patients could and probably should try it themselves because cannabis is not harmful.
Parkinson’s disease is the second most common neurodegenerative disease, preceded only by Alzheimer’s and dementia.
Only, instead of causing you to lose your memory, Parkinson’s affects your ability to control your muscle movements. Affecting between 5 and 19 people per every 100,000 around the globe, this disease of aging has wide-spread consequences.
Yet, while health care providers have known about Parkinson’s Disease for centuries, treatment of the condition remains challenging.
One of the biggest breakthroughs in Parkinson’s treatment was the invention of the drug Levodopa, which works to mimic one of the neurotransmitters most affected by the condition.
For many, however, the standard treatment for Parkinson’s simply isn’t enough to manage all related symptoms.
It is perhaps for this reason that a growing number of patients are expressing interest in medical cannabis.
Yet, when it comes to the science on the subject, researchers haven’t caught up with public enthusiasm.
“One sad part about the story of cannabis and Parkinson’s is that there is not a lot of clinical research supporting cannabis for [the disease],” explains Dr. Michele Ross, a neuroscientist and cannabis researcher, in an exclusive Green Flower video on cannabis & Parkinson’s.
“It’s not because it’s been shown that it doesn’t work,” she says. “They haven’t measured the right things. There hasn’t been a study looking at, say, does THC actually improve Parkinson’s mobility, or tremors, or the real aspects of the disease.”
Instead, most of the studies on the subject have been observational.
For example, a 2014 study published in the Journal of Psychopharmacology, for example, found that Parkinson’s patients given a high dose of cannabidiol (CBD) reported significant improvements in quality of life and overall well-being.
CBD is a plant chemical found exclusively in the cannabis plant.
However, while this study is intriguing, it did not examine exactly how or why the plant was helpful to patients. It simply measured their subjective experience with the herbal medicine.
The potential of cannabis for Parkinson’s Disease
Yet, when it comes to cannabis and Parkinson’s disease, not all hope is lost.
While there may not be a wealth of high-quality research on cannabis for Parkinson’s disease, there are several good reasons why so many researchers and patients are interested in the plant.
The herb contains several chemical compounds that have properties which may be helpful in Parkinson’s patients, potentially making the disease more manageable. These properties include:
Parkinson’s disease is a neurodegenerative condition. This means that, over time, nerve cells become damaged and eventually die.
“Parkinson’s is a disease where you have your dopamine cells that are important for initiating and maintaining movement, they’re the ones that are being damaged,” explains Ross.
The dopamine cells in question are motor neurons located in the basal ganglia, a motor region located deep in the center of the brain that enables the subconscious processing of movement.
When these cells begin to die off, the damage interferes with the brain’s ability to communicate conscious movements to the rest of the body.
Finding some way to prevent damage to these brain cells is necessary to prevent the continuation of Parkinson’s disease.
“If you can protect those cells from damage and from further damage and further neurodegeneration,” begins Ross, “you can halt the progression of that disease. Or, at least slow it down.”
Here’s where cannabis comes into the story.
Both cannabidiol (CBD) and tetrahydrocannabinol (THC) are neuroprotective antioxidants. In fact, even a patent owned by the U.S. Government presents the idea that CBD is a more powerful antioxidant than vitamins C and E.
“CBD is a powerful antioxidant and neuroprotectant,” says Ross. “Neuroprotectant means protecting the brain.”
Antioxidants are compounds that work to prevent damage from stress and free-radical toxicity. Free radicals are molecules that cause harm to DNA and cells, including neurons.
While the body produces free radicals naturally during cell metabolism, stress-related damage happens when the impact of these radical molecules goes unchecked by antioxidants.
Already, cannabis compounds have demonstrated neuroprotective effects in another common neurodegenerative disorder, multiple sclerosis (MS).
For example, a study published in the Journal of Neuroimmune Pharmacology back in 2015 cited evidence that oral THC treatment seemed to slow the progression of MS in human patients when compared to placebo.
The second major way that cannabis may prove helpful for Parkinson’s disease is due to the herb’s anti-inflammatory properties.
Specifically, non-intoxicating CBD is expected to have the most anti-inflammatory potential.
Finding new compounds that can successfully reduce neuroinflammation is a big deal.
When nerve cells become damaged, they swell. In the case of Parkinson’s this contributes to excess inflammation in the brain. This chronic, excess inflammation can worsen disease progression over time.
For example, a 2011 study published in the journal Plos One found that the cannabis compound reduced neuroinflammation associated with amyloid plaques in experimental models, which are protein plaques implicated in the progression of Alzheimer’s disease.
In another 2011 review in Free Radical Biology and Medicine, author George Booze from the University of Mississippi Medical Center points out that there is a growing body of emerging preclinical evidence suggesting that the anti-inflammatory properties of CBD may be helpful for a variety of neurological diseases.
“CBD, we know, is anti-inflammatory,” Ross explains. “THC is both pro- and anti-inflammatory, and so sometimes they sort of negate each other. CBD is really going to be the most powerful thing to protect that brain and slow Parkinson’s.”
3. Symptom relief
While substantial clinical evidence for cannabis as a treatment of Parkinson’s Disease is lacking, anecdotal reports and case studies have been far from shy about the potential benefits of the herb.
For example, a survey of Parkinson’s patients conducted among patients at a care center in the Czech Republic found that 45 percent of Parkinson’s patients that consumed cannabis found at least some benefit to consuming the herb.
Of these, about 31 percent reported improvements in tremor. Nearly 45 percent felt that the plant improved symptoms of bradykinesia, which refers to the slowed movement often experienced by Parkinson’s patients.
Another 38 percent of those individuals found that taking cannabis also eased rigidity, even though the patients also continued to use the medications prescribed to them by their doctors throughout their self-managed cannabis regimens.
Yet, shakes and trembles are not the only symptoms of Parkinson’s Disease.
Dopamine may be the neurotransmitter responsible for motor control, but the compound also is key for interpreting sensations of pleasure and reward.
Dopamine is also implicated in attention, meaning that Parkinson’s patients also often experience changes in mood and cognition unrelated to the shear stress of having a chronic condition.
While CBD may be the primary anti-inflammatory and neuroprotective agent in medical cannabis, the herb’s more famous psychoactive constituent may be useful for those hoping to improve mood and get a handle on sleep.
Unlike CBD, early research suggests that THC stimulates the production of melatonin, which is the chemical compound that helps lull the body to sleep at night.
The euphoric effect of psychoactive cannabis may also be beneficial to Parkinson’s patients, inspiring relaxation, promoting laughter, and encouraging a positive mood.
Ed. Note: Both my parents had Type 2 diabetes. Both probably died from complications from the disease. We know so little about the healing properties of cannabis and it truly needs more research.
Nobody wants to develop diabetes, but it happens all the time and is becoming more prevalent in our society.
Type 2 diabetes is the most common form, comprising almost 95 percent of all diagnosed cases of diabetes. This form of diabetes is characterized by high blood sugar levels, insulin resistance, and low levels of insulin.
This is a very serious condition that can result in things like heart disease, stroke, blindness, kidney failure, and more.
Type 2 diabetes affects at least 29 million people in the U.S. alone. The deeper you dive into the statistics and complications around this ailment, the more alarming it is.
And there’s also the rising economic toll. For instance, in 2012, diabetes cases cost the U.S. an estimated $245 billion. Staggering to say the least.
Luckily, type 2 diabetes can be prevented by eating healthy and maintaining an active lifestyle. And we are also learning – through scientific evidence – how cannabis can play a role, not only in prevention but also treatment.
The surprising effect of the cannabinoid THCV
While cannabinoids like tetrahydrocannabinol (THC) and cannabidiol (CBD) get the most mainstream attention, they are really the tip of the proverbial iceberg when you consider all the other compounds in cannabis including other cannabinoids, terpenes, and flavonoids.
However, there is one cannabinoid growing in popularity, and for good reason. Tetrahydrocannabivarin (THCV) has been referred to as ‘the sports car of cannabinoids’ by Steep Hill Laboratories because of how it affects euphoria.
And euphoria is only a small part of the equation here. As with every cannabinoid, there are valuable healing properties in THCV, which are being applied to various ailments, including diabetes.
Let’s take a look at how THCV can keep type 2 diabetes in check.
THCV’s effect on insulin levels
Insulin levels are at the heart of monitoring and treating diabetes.
A 2013 study looked specifically at how THCV affected insulin levels and insulin processing in mice. They found that this cannabinoid can improve glucose tolerance and restore insulin signaling.
The study concluded:
“Based on these data, it can be suggested that THCV may be useful for the treatment of the metabolic syndrome and/or type 2 diabetes (adult onset diabetes), either alone or in combination with existing treatments.”
Another study from 2013, this time conducted by Harvard Medical School and the Beth Israel Deaconess Medical Center looked at 4,657 male subjects. The study found:
“Subjects who reported using marijuana in the past month had lower levels of fasting insulin and HOMA-IR [insulin resistance], as well as smaller waist circumference and higher levels of HDL-C [high-density lipoprotein or ‘good’ cholesterol].”
THCV as an appetite suppressant
Researchers have found that THCV can suppress appetite. Overeating and poor diet contribute to obesity, which in turn contributes to diabetes, so this property of THCV should be of particular interest to diabetics or people struggling with obesity.
If someone is overweight or obese – critical risk factors for type 2 diabetes – they may be able to benefit from incorporating strains that are high in THCV.
On the flipside, this cannabinoid is not ideal for conditions like cancer, HIV/AIDS, or Crohn’s disease.
THCV could be considered an ‘energetic’ cannabinoid
The psychoactivity brought on by strains high in THCV has been described has ‘clear-headed’ and ‘energizing’, which could inspire increased physical activity for a lot of people.
Although the effect typically does not last as long compared to THC-dominant strains, this could be a great example where micro-dosing throughout the day would give you more benefit.
And if you are vaporizing your cannabis, THCV has a much hotter boiling point (428°F) compared to THC (314°F), so turn those vaporizers up!
What strains are high in THCV?
The benefits of THCV for preventing diabetes, and helping those that suffer from diabetes are undeniable. The logical follow up question then becomes ‘what strains are high in THCV?’
When it comes to strains high in THCV, some of the most commonly mentioned strains are Durban Poison, Doug’s Varin, Jack the Ripper, Dutch Treat, Pineapple Purps, and Skunk #1.
THCV levels are not as high as THC and CBD, so when you see a flower strain that has .5% versus 1% THCV, that’s a very significant jump.
Be aware that high THCV levels are associated with sometimes intense psychoactivity, which comes on very quick. It’s important to keep that in mind when you are consuming strains that are high in THCV, or recommending them to others.
Do you have any experience with cannabis and type 2 diabetes? Please feel free to join the conversation in the comment section below!
Ed. Note: The research is probably a bit misleading as it wasn’t controlled and it was an observational study, which means it’s very difficult to ascertain the effectiveness of pain relief. So it’s probably not an accurate depiction of the possible pain relief with the use of cannabis.
The cannabis plant is one of the oldest pain medications around.
In fact, references to the herb’s therapeutic properties have been dated back to sometime between 3494 and 2857 BCE, when the plant was included in one of the oldest known Chinese medical texts, Shen Nung Pen Ts’ao Ching.
In the modern day, novel uses for the herb continue to prove this plant’s medicinal value.
Easy access to medical cannabis dispensaries in the United States, for example, has been linked to reduced opioid overdose deaths and prescriptions.
In studies of cancer patients, cannabis-based medicines have already been found to be effective in relieving pain and improving quality of life.
But, what about chronic pain unrelated to cancer?
A new study from Australian researchers suggests that when it comes to chronic pain, cannabis may not always be effective.
Medical cannabis patients, however, can still breathe a sigh of relief.
Like all studies, this research highlights a potential trend, but the results still cannot be applied broadly to all circumstances.
New study finds no evidence that cannabis helps long-term pain
A new study published July 2018 in the well-respected journal Lancet found no evidence that illegally purchased cannabis effectively reduces long-term pain or reduces the use of opioid pain medications.
In fact, over the four-year study duration, the research found that cannabis consumers tended to report higher levels of pain and anxiety than their non-consuming counterparts.
“People who used cannabis had greater pain and lower self-efficacy in managing pain,” the authors write, “and there was no evidence that cannabis use reduced pain severity or interference or exerted an opioid-sparing effect.”
The paper defines “self-efficacy” as a person’s belief that they can go about their daily lives while experiencing pain. Pain interference refers to the amount that pain disrupts daily activities, like going to the store, cooking, cleaning, and other general day-to-day tasks.
This research also looked at “opioid-sparing” as a way to test whether or not people used fewer opioid pain medications to manage their symptoms during daily life.
The entire study included 1514 participants, 295 (26%) of which reported using cannabis for pain management.
To qualify for the research, patients were required to have experienced pain lasting longer than three months. They also had to be currently prescribed an opioid medication, including fentanyl, morphine, oxycodone, buprenorphine, methadone, or hydromorphone.
The study, funded by the Health and Medical Research Council and the Australian Government, is one of the longest and largest studies on cannabis and pain management available.
Cannabis may still reduce pain
While this study is one of the first to look at cannabis for pain management over the long term, there are still some contentions to keep in mind.
This research recruited patients at pharmacies throughout Australia. Yet, medical cannabis was not decriminalized in Australia until 2016.
Recruitment for this study continued between 2012 and 2014, prior to significant cannabis reform. This indicates that the participants in this study likely would not have had safe access to consistent, targeted, or high-quality medical cannabis products.
In fact, other than reporting the frequency of cannabis use among the participants, no information regarding the types of cannabis consumed, how the herb was consumed, or which specific products were used was mentioned in the research.
The study authors acknowledge this weakness, explaining that “participants had access only to illicit cannabis and were not taking cannabis as part of structured pain management under medical supervision.”
Overall, the study found that those who consumed cannabis also tended to report greater amounts of pain than those who did not. Yet, it is still unclear whether or not patients gravitated toward the plant in an attempt to alleviate pain symptoms that were not well-controlled by their previous medications.
In addition, the numbers crunched in this study are at odds with the participants’ perspective of how cannabis managed their pain.
In self-reports, individuals rated cannabis as highly effective for pain management. On average, the herb was given a seven out of 10 in terms of pain reduction, with 10 being “extremely effective”.
It is important to keep in mind, however, that while this study found no statistical correlation between cannabis and chronic pain relief it doesn’t necessarily mean that cannabis is not effective for pain.
Instead, this data may indicate that cannabis is not associated with effective pain management given these particular circumstances.
In their discussion, the authors draw attention to this fact, writing “although we found no significant association between cannabis use and pain, it is difficult to completely understand the effects of cannabis on pain in an observational study.”
Overall, the authors encourage large-scale clinical trials to truly test the efficacy of cannabis for chronic pain management.
What you need to know about cannabis for pain
While larger trials are needed, this research does draw attention to an interesting fact: the cannabis plant may not always work like it is often marketed.
Instead of being a blind cure-all for pain, the plant may be more effective in some situations than in others.
Exactly when cannabis works for pain and when it doesn’t is something that scientists still need to explore.
However, there is some early evidence that may begin to provide some explanation for the results published in this research.
1. Dosage matters
While taking a puff or two off of a vape may ease pain at first, continuing to do so may actually cause you to become more sensitive to pain.
This means that in low to moderate doses, the plant may successfully ease some types of pain. However, as you increase the dose during a single session, the opposite can occur.
In the trial, for example, healthy volunteers were given an injection of capsaicin, a compound best known for providing the spicy kick in hot peppers.
Patients then smoked cannabis with varying percentages of THC, the lowest being 2 percent, then 4 percent, then 8 percent.
The researchers found that those given moderate doses of THC experienced the most pain relief compared to placebo. After smoking the cannabis with the highest levels of THC, participants were more likely to experience a hypersensitivity to pain.
While a larger trial is needed, taking too high of a dose of cannabis too quickly seems to increase sensitivity to pain, not provide more relief.
Because of this potential trend, it is highly recommended for medical cannabis patients with complex pain conditions to work with a medical professional to better optimize their pain management.
2. Tolerance can develop over time
There may be another solvable reason why participants in the study did not experience adequate pain relief with cannabis.
Cells in the human body are continuously adapting to their environments. After receiving high doses of cannabis for a prolonged period of time, cells may become less sensitive to the herb.
Cells in the nervous system are particularly responsive to cannabis compounds.
These cells feature special landing sites, called cannabinoid receptors, on their surfaces that allow them to respond to the effects of THC and other cannabis compounds.
Over time, these cells “shut down”, so to speak, these receptor sites after being flooded continuously with cannabis compounds.
When cells de-activate their landing sites, that’s when cannabis tolerance develops.
In chronic consumers, this tolerance can reduce the effectiveness of the herb over time.
While consuming more of the plant may cause temporary relief, the overall effects may be blunted in comparison to someone who has recently started using cannabis.
Managing tolerance is yet another reason why working with a professional is a good idea when using cannabis to manage chronic pain conditions.
While many participants try to adjust their cannabis consumption by themselves, patients who rely solely on illicit cannabis may lack access to products and cannabis varieties that would be more helpful for keeping tolerance in check.
3. Cannabis may enhance pain signaling in the spinal cord
The relationship between cannabis and pain is a complicated one. Many consumers swear that the herb is what helps them manage their pain and get through the day.
However, in the laboratory, scientists have discovered that compounds in the plant can have some odd effects.
Cannabis may be one of the oldest cultivated pain medications around, but preclinical research has found that the activation of certain cannabinoid receptors in the spinal cord may actually trigger pain signaling.
A 2009 study published in Science found that engaging certain cannabinoid receptors in the spinal cord blocks the release of neurotransmitters that are typically associated with pain relief.
While more research on this topic is sorely needed, this finding could potentially explain why cannabis compounds may sometimes make individuals more sensitive to pain. Yet, there have been no studies testing exactly how real cannabis components impact this phenomenon.
Bottom line? The story behind cannabis for pain management is more complicated than it seems.
While there is a body of scientific evidence that suggests that the herb, in fact, may be very helpful for pain, there are also circumstances where that might not be true.
For those hoping to take advantage of the emerging science regarding cannabis and pain, working with an herb-friendly medical professional is always advised.
Many cannabis consumers have experienced the infamous red eye. The eyes are often the most common giveaway after a serious session with a vaporizer.
Yet, while some may find the herb’s visible effects on the eyes to be burdensome, there are several surprising ways that cannabis supports ocular health.
From easing symptoms of eye disease to staving off degenerative blindness, here’s what you need to know about how cannabis affects the eyes:
How does cannabis affect the eyes?
As it turns out, cannabis may help you see things a little differently. Research suggests that the herb can have an impact on every organ in the body, including the eyes.
While it may sound too good to be true, cannabis compounds work their magic in the eyes by tapping into one of the largest cellular communication networks in vertebrates. This network is the endocannabinoid system (ECS).
Cannabis compounds interact with the ECS by engaging a special type of cell receptor, called a cannabinoid receptor.
The human eye happens to express high levels of one particular cannabinoid receptor, the CB1. Vision processing centers of the brain also feature a bounty of these landing sites.
In addition, preclinical investigations suggest that the ECS plays a crucial role in our vision.
A 2016 primate study published in Neural Plasticity has found that manipulating cannabinoid receptors changes the way electroretinographic waves pass through the retina.
These waves are measured by an electroretinogram, which records the electrical response of the eye to a light stimulus. The researchers found that cannabinoid receptors moderated the eye’s response to light.
The ways in which cannabis affects eyesight needs further investigation. However, this early research offers even more reason to investigate cannabis as a treatment for diseases of the eye.
Already, there are several acute ways that cannabis affects the eyes. While some are spectacular, like improved night vision, not all of the effects are enjoyable. Shortly after consuming the herb, it is not uncommon to experience:
1.) Red Eye
Red eyes are not always the favorite cannabis side effect. While red eyes may be a tell-tale giveaway that you’ve consumed a little cannabis, those who experience tension around the eye might appreciate the relaxing effects of the herb.
Cannabis lowers blood pressure. This causes capillaries and blood vessels to dilate, leading to what is commonly referred to as red eye.
Wider capillaries mean blood flows into the eyes, reducing intraocular pressure. In a way, this a form of relaxation for the eyes. This could be beneficial for patients with painful ocular conditions like glaucoma.
It’s not uncommon for some people to experience an allergic reaction in the eyes after smoking cannabis. This reaction can be triggered by an allergy to smoke, residual molds, or the cannabis plant itself.
Signs of allergy typically include itchiness, redness, inflammation, tearing, and dryness.
In 2015, research from the American College of Allergy, Asthma, and Immunology suggests that cannabis allergy is similar to Hay Fever, causing eye irritation and an itchy nose for those exposed to smoke, pollen, or plant material.
3.) Enhanced night vision
Laboratory research like that mentioned above has found that cannabinoid receptors seem to help the eyes respond to light.
Additional research from 2016 suggests that cannabis compounds, like psychoactive THC, connect with these receptors. Engaging these receptors is thought to improve the ability to see in low-light conditions.
For the past three decades, researchers have speculated that cannabis may also improve night vision. In the 1990s, M.E. West, a pharmacologist, noticed that Jamaican fishermen who consumed a cannabis elixir had an “uncanny ability to see in the dark.”
A small study conducted in 2004 tested the effects of traditional cannabis Kif and a synthetic THC in three Moroccan individuals. Kif is a mixture of cannabis and tobacco. This small experiment found a dose-dependent relationship between cannabis consumption and improved night vision.
4.) Visual processing
Interestingly, recent evidence suggests that the endocannabinoid system contributes to visual development in the brain.
A study from University of Waterloo, University of Auckland and Brown University found that babies exposed to cannabis in utero scored significantly higher in visual processing tests.
While babies exposed to alcohol scored lower in visual processing tests, those exposed to cannabis had improved global motion perception.
This is certainly not a reason to consume cannabis during pregnancy, but these findings do add fuel to the idea that cannabinoids and the ECS help the eyes and brain make sense of visual information.
Cannabis and eye disease
Cannabis affects the eyes in a variety of different ways.
While there is still much to discover about cannabis and eye health, a growing body of evidence suggests that the herb may be useful in a number of diseases of the eye.
Some of these diseases include:
The notorious red eye that cannabis causes may also be the reason the herb is thought to be so helpful for glaucoma patients. Glaucoma is a disease that damages the optic nerve, and it is considered one of the leading causes of blindness in the world.
Researchers have been studying the effects of cannabis on glaucoma since as early as the 1970s. In one experiment with 16 human participants, inhaled cannabis successfully reduced the intraocular pressure that contributes to pain and degeneration with this disease.
Patients felt relief for a total of three to four hours after cannabis treatment. Patients with high blood pressure and glaucoma experienced the longest and most significant results. Research from 1980 and 2000 corroborate these findings.
2.) Neurodegenerative blindness
In 2014, research published in Experimental Eye Research suggested that cannabis medicines may be able to slow down degenerative blindness. Specifically, cannabis compounds prevented the death of photoreceptors in those with retinitis pigmentosa.
The research used rodents as test subjects. Rats were treated with a synthetic cannabinoid over the course of 90 days. After the three months were up, the scientists checked on the progression of their blindness.
Rats treated with the cannabinoid had an impressive 40 percent more photoreceptors than their nontreated counterparts. This is strong evidence that cannabis-like therapies can slow down ocular degeneration in neurodegenerative blindness.
Studies in other areas have found that the herb contains powerful neuroprotective antioxidants, which may lend a hand in a variety of age-associated conditions, not just poor eyesight.
3.) Diabetic retinopathy
A 2006 preclinical study found that cannabidiol (CBD), a cannabis compound that does not cause a psychotropic “high”, may help protect the eyes of diabetics.
Diabetic retinopathy is a side effect of diabetes and it causes damage to the blood vessels in the retina. The retina is the light-sensitive part of the eye. In diabetic retinopathy, the nerve cells in the eye begin to die, which directly affects eyesight.
As a potent antioxidant, researchers believe that CBD can check back some of the toxicity in the retina that contributes to degeneration.
A study claiming chronic cannabis consumption damages the retina has recently made headlines across the net. Yet, this 2006 research suggests that some cannabis compounds may actually protect the retina from damage. Perhaps it just depends on how you use the herb.