CBD oil and cancer: 9 things to know
BY Cynthia DeMarco
CBD oil (cannabidiol) is everywhere these days. Once available only at novelty or vitamin shops, it’s now also at your local grocery store, pharmacy or even yoga studio.
It comes in many forms: oils that are dropped under the tongue, roll-ons that are applied to the skin and even solutions for vaping. Some producers extract CBD oil and add it into foods to create edible products.
But what is CBD oil exactly, and how does it affect cancer patients? Can it really treat — or even cure — cancer or relieve its symptoms? To separate fact from fiction, we spoke with our Kimberson Tanco, M.D. Here’s what he wants cancer patients to know.
What is CBD oil, and how does it differ from marijuana and hemp?
Marijuana and hemp are both varieties of the cannabis sativa plant. Both contain cannabidiol (CBD) and tetrahydrocannabinol (THC) — the two most-common, known active ingredients.
The main difference is that hemp has far less THC than a typical marijuana plant. And unlike THC, CBD is not a psychoactive agent, so there’s less possibility that it will cause the same mental confusion, drowsiness or hallucinations that often come with THC.
Is there any truth to the claims that CBD oil can cure cancer?
Right now, no. There is no evidence that CBD oil can cure cancer.
What, if anything, can CBD oil do to alleviate the symptoms of cancer or the side effects of cancer treatment?
It’s hard to say if CBD oil can alleviate cancer symptoms or cancer treatment side effects, because the studies are pretty mixed and even fewer are standardized.
There have been reports that cannabinoids like THC and CBD may be helpful for nausea and vomiting and anorexia, as well as neuropathy, anxiety, depression and insomnia. Synthetic cannabinoids like dronabinol have been approved for use with chemotherapy-induced nausea and vomiting, but have not been shown to be superior to conventional anti-nausea medications.
Have any CBD-oil derived products been approved by the U.S. Food and Drug Administration (FDA) to treat cancer, its symptoms, or the side effects caused by its treatment?
Have any products using CBD-oil been approved by the FDA to treat anything?
Yes. Epidiolex. It was originally approved in 2018 for the treatment of two conditions, both related to epilepsy: Lennox-Gastaut syndrome and Dravet syndrome. But aside from Epidiolex, no CBD product has been approved by the FDA for any other medical purpose.
What are the dangers of using CBD oil?
Quality, cleanliness and regulation are the biggest concerns.
All drugs and dietary supplements are regulated by the FDA. But as long as CBD oil is not marketed as a medicine or a dietary supplement, producers can get around that policy. So right now, CBD oil is very unregulated. That means it’s hard to know how much CBD or THC is really in any given product. Certain hemp CBD products have been found to contain significantly less CBD or more THC than advertised.
In terms of purity, THC and CBD are both extracted from hemp and marijuana using essentially similar processes. But trace amounts of THC could still end up in CBD oil. And if the THC is at a high enough concentration, it could produce the psychoactive effects that THC is known for.
Second, if a lab produces both CBD and THC products, there can be cross-contamination — whether it’s through extraction, handling or packaging.
Third, the plant itself may have higher levels of THC than expected. This could be due to its environment, prolonged flowering periods or cross-contamination and pollination between male and female plants, resulting in offspring with higher THC content. This especially affects hemp plants, which should have less than 0.3% THC levels.
Finally, there have been some reports of people getting infections after using CBD and cannabis products. This is especially concerning for immunocompromised patients, who are already susceptible to bacterial and fungal infections.
Studies on a certain CBD manufacturer showed its products were contaminated with a chemical known as 5F-ADB, which mimics THC. 5F-ADB is classified by the U.S. Drug Enforcement Administration as illegal, potentially addictive and with no accepted medical use.
Other sorts of substances have been found in CBD products, too, such as dextromethorphan, which is an ingredient in cough medicines. Heavy metals like lead and arsenic, pesticides and mold have also been found in CBD products.
Does CBD oil have any side effects?
CBD oil can adversely affect liver function. In fact, this is on the warning label for Epidiolex.
And in lab studies, CBD has been shown to inhibit certain enzymes responsible for the metabolism of drugs, such as CYP2D6 and CYP3A4. This can affect how drugs work and affect our bodies, either by reducing their efficiency or making them more dangerous. This includes chemotherapy and other medications.
This is very important for cancer patients to understand, as many people think CBD oil is not a medicine. They think of it more as a vitamin or a supplement, so they might not let their doctors know they’re using it. Patients might not realize it can be potentially harmful. So, it’s very important to tell your doctor if you’re using CBD oil.
Is CBD oil even legal?
CBD has a very complex legal status right now.
At the national level, any product of marijuana — including CBD — is still technically illegal when used medically. Although the 2018 Farm Bill legalized the production of hemp nationally, that’s only permitted if it’s not marketed for medical use or as a dietary supplement. CBD products intended for medical use should undergo an FDA review process.
State laws vary. In Texas, the Compassionate Use Act allows for the use of medical marijuana for certain conditions. Originally only for intractable epilepsy, the law was expanded this year to include cancer and certain neurodegenerative conditions, such as Parkinson’s and multiple sclerosis.
But the application of this law is pretty jumbled right now. So, while it may be legal to use CBD in a state like Colorado or Alaska, if an employer follows federal regulations, the standardization and quality of a CBD product matters. Because if there’s even a small percentage of THC in that product, then a drug test might come back positive. And this could result in legal issues for the user.
What’s the most important thing cancer patients should know about CBD oil?
There’s still a lot to learn. So always let your health care team know if you are using CBD oil. That way, we can make sure nothing interacts adversely with your cancer treatments or other medications.
Also, avoid products with health-related claims on their labels. The only product approved by the FDA for its medical value is Epidiolex.
Wondering whether you should use CBD oil to cope with cancer treatment and its side effects? We spoke with Kimberson Tanco, M.D., to separate fact from fiction.
Marijuana and Cancer
Marijuana is the name given to the dried buds and leaves of varieties of the Cannabis sativa plant, which can grow wild in warm and tropical climates throughout the world and be cultivated commercially. It goes by many names, including pot, grass, cannabis, weed, hemp, hash, marihuana, ganja, and dozens of others.
Marijuana has been used in herbal remedies for centuries. Scientists have identified many biologically active components in marijuana. These are called cannabinoids. The two best studied components are the chemicals delta-9-tetrahydrocannabinol (often referred to as THC), and cannabidiol (CBD). Other cannabinoids are being studied.
At this time, the US Drug Enforcement Administration (DEA) lists marijuana and its cannabinoids as Schedule I controlled substances. This means that they cannot legally be prescribed, possessed, or sold under federal law. Whole or crude marijuana (including marijuana oil or hemp oil) is not approved by the US Food and Drug Administration (FDA) for any medical use. But the use of marijuana to treat some medical conditions is legal under state laws in many states.
Dronabinol, a pharmaceutical form of THC, and a man-made cannabinoid drug called nabilone are approved by the FDA to treat some conditions.
Different compounds in marijuana have different actions in the human body. For example, delta-9-tetrahydrocannabinol (THC) seems to cause the “high” reported by marijuana users, and also can help relieve pain and nausea, reduce inflammation, and can act as an antioxidant. Cannabidiol (CBD) can help treat seizures, can reduce anxiety and paranoia, and can counteract the “high” caused by THC.
Different cultivars (strains or types) and even different crops of marijuana plants can have varying amounts of these and other active compounds. This means that marijuana can have different effects based on the strain used.
The effects of marijuana also vary depending on how marijuana compounds enter the body. The most common ways to use marijuana are in food (edible marijuana) and by smoking or vaping it (inhaled marijuana):
- Edible marijuana: When taken by mouth, such as when it’s used in cooking oils, drinks (beer, tea, vodka, soda), baked goods (biscuits, brownies, cookies), and candy, the THC is absorbed poorly and can take hours to be absorbed. Once it’s absorbed, it’s processed by the liver, which produces a second psychoactive compound (a substance that acts on the brain and changes mood or consciousness) that affects the brain differently than THC. It’s important to know that the amount of THC in foods that have had marijuana added to them is often unknown and getting too much THC might cause symptoms of overdose.
- Inhaled marijuana: When marijuana is smoked or vaporized, THC enters the bloodstream and goes to the brain quickly. The second psychoactive compound is produced in small amounts, and so has less effect. The effects of inhaled marijuana fade faster than marijuana taken by mouth.
How can marijuana affect symptoms of cancer?
A number of small studies of smoked marijuana found that it can be helpful in treating nausea and vomiting from cancer chemotherapy.
A few studies have found that inhaled (smoked or vaporized) marijuana can be helpful treatment of neuropathic pain (pain caused by damaged nerves).
Smoked marijuana has also helped improve food intake in HIV patients in studies.
There are no studies in people of the effects of marijuana oil or hemp oil.
Studies have long shown that people who took marijuana extracts in clinical trials tended to need less pain medicine.
More recently, scientists reported that THC and other cannabinoids such as CBD slow growth and/or cause death in certain types of cancer cells growing in lab dishes. Some animal studies also suggest certain cannabinoids may slow growth and reduce spread of some forms of cancer.
There have been some early clinical trials of cannabinoids in treating cancer in humans and more studies are planned. While the studies so far have shown that cannabinoids can be safe in treating cancer, they do not show that they help control or cure the disease.
Relying on marijuana alone as treatment while avoiding or delaying conventional medical care for cancer may have serious health consequences.
Possible harms of marijuana
Marijuana can also pose some harms to users. While the most common effect of marijuana is a feeling of euphoria (“high”), it also can lower the user’s control over movement, cause disorientation, and sometimes cause unpleasant thoughts or feelings of anxiety and paranoia.
Smoked marijuana delivers THC and other cannabinoids to the body, but it also delivers harmful substances to users and those close by, including many of the same substances found in tobacco smoke.
Because marijuana plants come in different strains with different levels of active compounds, it can make each user’s experience very hard to predict. The effects can also differ based on how deeply and for how long the user inhales. Likewise, the effects of ingesting marijuana orally can vary between people. Also, some chronic users can develop an unhealthy dependence on marijuana.
There are 2 chemically pure drugs based on marijuana compounds that have been approved in the US for medical use.
- Dronabinol (Marinol®) is a gelatin capsule containing delta-9-tetrahydrocannabinol (THC) that’s approved by the US Food and Drug Administration (FDA) to treat nausea and vomiting caused by cancer chemotherapy as well as weight loss and poor appetite in patients with AIDS.
- Nabilone (Cesamet®) is a synthetic cannabinoid that acts much like THC. It can be taken by mouth to treat nausea and vomiting caused by cancer chemotherapy when other drugs have not worked.
Nabiximols is a cannabinoid drug still under study in the US. It’s a mouth spray made up of a whole-plant extract with THC and cannabidiol (CBD) in an almost one to one mix. It’s available in Canada and parts of Europe to treat pain linked to cancer, as well as muscle spasms and pain from multiple sclerosis (MS). It’s not approved in the US at this time, but it’s being tested in clinical trials to see if it can help a number of conditions.
How can cannabinoid drugs affect symptoms of cancer?
Based on a number of studies, dronabinol can be helpful for reducing nausea and vomiting linked to chemotherapy.
Dronabinol has also been found to help improve food intake and prevent weight loss in patients with HIV. In studies of cancer patients, though, it wasn’t better than placebo or another drug (megestrol acetate).
Nabiximols has shown promise for helping people with cancer pain that’s unrelieved by strong pain medicines, but it hasn’t been found to be helpful in every study done. Research is still being done on this drug.
Side effects of cannabinoid drugs
Like many other drugs, the prescription cannabinoids, dronabinol and nabilone, can cause side effects and complications.
Some people have trouble with increased heart rate, decreased blood pressure (especially when standing up), dizziness or lightheadedness, and fainting. These drugs can cause drowsiness as well as mood changes or a feeling of being “high” that some people find uncomfortable. They can also worsen depression, mania, or other mental illness. Some patients taking nabilone in studies reported hallucinations. The drugs may increase some effects of sedatives, sleeping pills, or alcohol, such as sleepiness and poor coordination. Patients have also reported problems with dry mouth and trouble with recent memory.
Older patients may have more problems with side effects and are usually started on lower doses.
People who have had emotional illnesses, paranoia, or hallucinations may find their symptoms are worse when taking cannabinoid drugs.
Talk to your doctor about what you should expect when taking one of these drugs. It’s a good idea to have someone with you when you first start taking one of these drugs and after any dose changes.
What does the American Cancer Society say about the use of marijuana in people with cancer?
The American Cancer Society supports the need for more scientific research on cannabinoids for cancer patients, and recognizes the need for better and more effective therapies that can overcome the often debilitating side effects of cancer and its treatment. The Society also believes that the classification of marijuana as a Schedule I controlled substance by the US Drug Enforcement Administration imposes numerous conditions on researchers and deters scientific study of cannabinoids. Federal officials should examine options consistent with federal law for enabling more scientific study on marijuana.
Medical decisions about pain and symptom management should be made between the patient and his or her doctor, balancing evidence of benefit and harm to the patient, the patient’s preferences and values, and any laws and regulations that may apply.
The American Cancer Society Cancer Action Network (ACS CAN), the Society’s advocacy affiliate, has not taken a position on legalization of marijuana for medical purposes because of the need for more scientific research on marijuana’s potential benefits and harms. However, ACS CAN opposes the smoking or vaping of marijuana and other cannabinoids in public places because the carcinogens in marijuana smoke pose numerous health hazards to the patient and others in the patient’s presence.
Learn how marijuana and drugs derived from the marijuana plant can affect cancer-related symptoms.