Over the past 2 decades, many scientists have looked at the use of cannabis to treat cancer, but it has only been in the past decade that scientists have found that a key ingredient in cannabis, CBD, is effective in treating cancer.
Cannabis has been used for millennia for treating a number of illnesses. Mentions of cannabis or hemp have appeared in texts dating back to almost 3000 BC.
Cancer, while only studied in-depth since the 1770s, had been mentioned in Egyptian texts dating as far back as 2500 BC. The Greek philosopher Hippocrates, the man is known as “the father of medicine” who lived from 460 BC until 370 BC, described several kinds of cancer. He named the disease karkinos or carcinos, which is the Greek word for crab. He named it this due to the appearance as he described “the veins stretched on all sides as the animal the crab has its feet”
Cannabis and Cancer
The mid- to late-1900s were a dark time for cannabis research in the United States. By 1937 all states had banned the sale of marijuana as an over-the-counter medication and the federal government had effectively stopped the legal production of marijuana and hemp by creating tax laws that required “stamps” (similar to stamps most states require cigarettes to carry today) so they could limit and essentially prevent the sale of cannabis.
But while there were laws in place preventing medical or personal use of the plant, some research was able to be done.
One of the first major studies regarding cancer and cannabis was to see if it could help cancer patients could hold down food and create a sense of hunger. Classic television and movies show us the stereotypical “stoner” getting the “munchies” after smoking marijuana. Scientists took this as a premise to see if it could help those who suffer from cancer. The studies resulted in a scientific paper being published that concluded that “THC is an effective antiemetic agent for many patients receiving cancer chemotherapy, and for some patients, it may be the only effective drug.”
Because laws made it nearly impossible to work with cannabis in the United States, scientist created a synthetic version of THC (tetrahydrocannabinol) to treat patients called nabilone. In double-blind studies conducted with a variety of different drugs, nabilone “appeared to be the more effective antiemetic for patients who received chemotherapy agents other than high dose cis-dichlorodiammineplatinum(II) (DDP)” (https://www.ncbi.nlm.nih.gov/pubmed/6250699)
DDP is a highly toxic platinum compound given to cancer patients for nausea and other side effects but causes a number of side effects of its own including:
- anaphylactic reactions
- elevations in liver function tests.
- hearing loss
- hypomagnesemia (magnesium deficiencies)
- myelosuppression (bone marrow suppression)
- nephrotoxicity (kidney damage)
- peripheral neuropathies
- tinnitus (https://www.researchgate.net/publication/22754929_Toxic_Effects_of_Cis-dichlorodiammineplatinum_II_in_Man)
As such cannabis and THC were considered a better alternative than DDP as the side effects weren’t toxic.
The original company that invented nabilone, Eli Lilly and Company, got it approved by the US Food and Drug Administration in 1985, but the FDA withdrew its approval in 1989. Nabilone wouldn’t be available in the US again until 2006 when Valeant Pharmaceuticals (who bought the rights from Eli Lilly) succeeded in getting the FDA to re-approve the drug.
One of the first major studies documenting the effects of CBD on any type of cancer was completed in 1998. The study, of with the abstract was published on the United States National Library of Medicine from the National Institute of Health (NIH), was entitled: The Peripheral Cannabinoid Receptor, Cb2, in Retrovirally-Induced Leukemic Transformation and Normal Hematopoiesis and looked at both CBD and THC in the treatment of leukemia. (https://www.ncbi.nlm.nih.gov/pubmed/10036999)
Since the 1998 study, about two dozen studies have been published on the NIH website regarding the treatment of various cancers with CBD, as a standalone treatment and in concert with THC.
The Endocannabinoid System and CBD
One of the biggest discoveries in the use of cannabis as a medical treatment came in 1992 when it was discovered that the humans (as well as many animals) have a natural system within their bodies to process and produce cannabinoids. This system, known as the endocannabinoid system (ECS) was found to have profoundly reaching effects on the body as it was intertwined with the brain, the central nervous system, and the peripheral nervous system. (https://www.ncbi.nlm.nih.gov/pubmed/1470919)
The ECS is comprised of fatty acid (lipids) based neurotransmitters that attach to receptors and receptor proteins specifically designed for cannabinoids. The ECS is responsible for the regulation and control of a number of processes in the body including:
- creating a feeling of motivation
- mediating cognition
- modulating motor activity
- postnatal development
- prenatal development
- processing the effects of cannabis when consumed
The ECS has 2 primary receptors CB1 (cannabinoid receptor 1) and CB2 (cannabinoid receptor 2). The CB1 receptors are found in throughout the brain, the central nervous system, and the peripheral nervous system. CB1 primarily binds with the substance anandamide, a fatty acid neurotransmitter, and THC. One other main endocannabinoid is arachidonoylglycerol (2-AG) which is active at both the CB1 and CB2 receptors and works with CBD. 2-AG and CBD are involved in the regulation of appetite, immune system functions, and pain management.
CBD words differently than THC on the CB1 and CB2 receptors. THC binds to these receptors to activate them. CBD activates these receptors without binding. This allows CBD to act as an antagonist when it comes to absorption of many neuromodulators (a substance that regulates brain function). Among the most common neuromodulators are:
This is beneficial because in some cases, these substances can be absorbed too quickly and cause deficiencies in the body. By acting as an antagonist, CBD can allow these substances to remain at normal levels to assist with normal functioning.
But at some point, the CBD needs to bind to something in the body or it would just be passed through as waste. This is where a protein receptor known as TRPV1 (transient receptor potential cation channel subfamily V member 1) or more commonly known as the vanilloid receptor 1 steps in.
CBD binds with TRPV1 and helps the body regulate pain, body temperature, and inflammation. In this respect, CBD works with this and other proteins in the body to develop the body’s homeostasis.
Cancer wreaks havoc on the immune system. It can cause it to go into hyperactivity or come to a point where it almost shuts down. Part of this is because immunosuppressants are given to patients. CBD works with the ECS to regulate the immune system. It activates the immune system when it’s not producing enough activity and it suppresses with it becomes hyperactive.
This is due to the interaction with the CB2 receptor. When activated by CBD, the CB2 receptors can reduce the production of inflammatory cytokine peptides (amino acid bonds) in the body and increase the anti-inflammatory cytokine peptides, thus allowing the body to get the proper immunoresponse.
What Is Cancer?
As many people know, cancer isn’t just one disease. In fact, in addition to the ability to affect vastly different areas of the body, it can appear in different forms. Cancer is defined as is a group of diseases that involve abnormal increases in the number of cells, with the potential to invade or spread to other parts of the body.
Cancers are determined by the type of cell that the cancer originated from. There are 5 different classes of cancer. They are:
- Carcinoma – The most common type of cancer, this class of cancer starts in epithelial cells (tissues that line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs). Almost all of the cancers involving the breasts, prostate, lungs, pancreas, and colon are this class of cancer.
- Sarcoma – These cancers originate in cells in connective tissues or mesenchymal cells such as bones, cartilage, fat, and nerve cells. They are generally located outside of bone marrow.
- Lymphoma and Leukemia – These 2 types of cancer are derived from blood cells. Leukemia is the most common type of cancer in children.
- Germ Cell Tumor – These cancers come from pluripotent cells in the body. Pluripotent cells are stem cells that have the potential to differentiate into any of the three germ layers (These cancers are most commonly found in the testicles of ovaries.):
- Endoderm – interior stomach lining, gastrointestinal tract, the lungs
- Mesoderm – muscle, bone, blood, urogenital
- Ectoderm – epidermal tissues and nervous system
- Blastoma – A cancer that derives from embryonic cell tissues. These are more commonly found in children than adults.
There are over 100 known cancer that can affect humans. Among the most common are:
- Acute Lymphoblastic Leukemia
- Acute Lymphocytic Leukemia (ALL)
- Acute Myeloid Leukemia (AML)
- Adenoid Cystic Carcinoma
- Adrenal Gland Cancer
- Atypical Mole Syndrome
- Basal Cell Carcinoma
- Bile Duct Cancer
- Birt Hogg Dube Syndrome
- Bladder Cancer
- Bone Cancer
- Brain Tumor
- Breast Cancer
- Carcinoid Tumor
- Cervical Cancer
- Chronic Lymphocytic Leukemia (CLL)
- Chronic Myeloid Leukemia (CML)
- Colorectal Cancer
- Ductal Carcinoma
- Endometrial Cancer
- Endometrial Cancer
- Esophageal Cancer
- Gastric Cancer
- Gastrointestinal Stromal Tumor – GIST
- Hodgkin’s Lymphoma
- Islet Cell Tumor
- Juvenile Polyposis Syndrome
- Kaposi Sarcoma
- Kidney Cancer
- Laryngeal Cancer
- Leukemia – Adult
- Leukemia – Childhood
- Liver Cancer
- Lobular Carcinoma
- Lung Cancer
- Lung Cancer – Small Cell
- Malignant Glioma
- Multiple Myeloma
- Myelodysplastic Syndrome (MDS)
- Nasopharyngeal Cancer
- Neuroendocrine Tumor
- Non-Hodgkin’s Lymphoma
- Oral Cancer
- Ovarian Cancer
- Pancreatic Cancer
- Pancreatic Neuroendocrine Tumors
- Parathyroid Cancer
- Penile Cancer
- Peritoneal Cancer
- Peutz-Jeghers Syndrome
- Pituitary Gland Tumor
- Polycythemia Vera
- Prostate Cancer
- Renal Cell Carcinoma
- Salivary Gland Cancer
- Skin Cancer
- Small Intestine Cancer
- Stomach Cancer
- Testicular Cancer
- Thyroid Cancer
- Wilms’ Tumor
Is CBD a Cure for Cancer? (Benefits and Side Effects)
In short, no. CBD won’t cure cancer and should never be used as a substitute for cancer treatment that’s prescribed by a doctor. However, CBD has been shown in a number of studies to help treat both the primary causes and the side effects of cancer.
One study regarding pancreatic cancer currently under investigation is looking at both CBD and THC. So far the research is promising as the abstract for the study states “In vitro studies consistently demonstrated tumor growth-inhibiting effects with CBD, THC, and synthetic derivatives. Synergistic treatment effects have been shown in two studies with the combination of CBD/synthetic cannabinoid receptor ligands and chemotherapy in xenograft and genetically modified spontaneous pancreatic cancer models.” (https://www.ncbi.nlm.nih.gov/pubmed/30706048)
Another study of CBD on breast cancer patients showed that non-psychoactive cannabidiol (CBD) and other CBs (cannabinoids) inhibited disease progression in breast cancer models.” And that “CBs are already administered to breast cancer patients at advanced stages of the disease, but they might also be effective at earlier stages to decelerate tumor progression.” (https://www.ncbi.nlm.nih.gov/pubmed/30987191)
A study regarding the use of intravenous CBD on tumors found “CBD conjugation or fusion decreases the systemic toxicity of both αCTLA4 + αPD-L1 combination therapy and IL-2, for example, eliminating hepatotoxicity with the CPI molecules and ameliorating pulmonary edema with IL-2. Both CBD-CPI and CBD-IL-2 suppressed tumor growth compared to their unmodified forms in multiple murine cancer models, and both CBD-CPI and CBD-IL-2 increased tumor-infiltrating CD8+ T cells. In an orthotopic breast cancer model, combination treatment with CPI and IL-2 eradicated tumors in 9 of 13 animals with the CBD-modified drugs, whereas it did so in only 1 of 13 animals with the unmodified drugs. Thus, the A3 domain of VWF can be used to improve the safety and efficacy of systemically administered tumor drugs with high translational promise.” In other words, when CBD (combined with other drugs) was injected into a tumor, it eradicated the tumor as opposed to the drugs that weren’t modified with CBD. (https://www.ncbi.nlm.nih.gov/pubmed/30971453)
And these are only 3 examples. Studies of the effects of CBD on cancer are occurring at a breakneck pace and have been increasing over the last few years due to changes in US laws,
While CBD alone won’t cure cancer, it can help treat it. It can also treat the side effects of chemotherapy. Traditionally CBD and cannabis have usually been a last resort for doctors to recommend and prescribe for patients in the final stages of the disease. But research is proving that CBD and cannabis can benefit patients moreso in the early stages of most cancers.
More research must and will be done in this area in the years to come to see how CBD affects the different types of cancers, but as for the chemotherapy side effects, CBD is an effective tool in curbing and even eliminating them.