1. Reduced Risk of Diabetes and Obesity

Several studies have shown that regular cannabis users have a lower body mass index, smaller waist circumferences, and reduced risk of diabetes and obesity. One 2011 report published in the American Journal of Epidemiology, based on a survey of more than fifty-two thousand participants, concluded that rates of obesity are about one-third lower among cannabis users.[176] This is despite the findings that participants tend to consume more calories per day, an activity that is potentially related to THC’s stimulation of ghrelin, a hormone that increases appetite but also increases the metabolism of carbohydrates. CBD on its own was shown in 2006 to lower the incidence of diabetes in lab rats,and 

in 2015 an Israeli-American biopharmaceutical collective began stage 2 trials related to using CBD to treat diabetes. Research has demonstrated that CBD benefits weight loss by helping the body convert white fat into weight-reducing brown fat, promoting noatherogenesisrmal insulin production and sugar metabolism.

In studying over 4,600 test subjects, researchers found that current cannabis users had fasting insulin levels that were up to 16 percent lower than their non-using counterparts, higher levels of HDL cholesterol that protects against diabetes, and 17 percent lower levels of insulin resistance. Respondents who had used cannabis in their lifetime but were not current users showed similar but less pronounced associations, indicating that the protective effect of cannabis fades with time.

Excess insulin promotes the conversion of sugars into stored fat and leads to weight gain and obesity. The research emerging about the interplay between cannabinoids and insulin regulation may lead to some major breakthroughs in the prevention of obesity and type 2 diabetes.

2. Better Cholesterol Profiles and Lowered Risk of Cardiovascular Disease

A 2013 study that measured data from 4,652 participants on the effect of cannabis on metabolic systems compared non-users to current and former users. It found that current users had higher blood levels of high-density lipoprotein (HDL-C) or “good cholesterol.” The same year, an analysis of over seven hundred members of Canada’s Inuit community found that, on average, regular cannabis users had increased levels of HDL-C and slightly lower levels of LDL-C (“bad cholesterol”).

4. Helps Maintain Brain Health and Create Resilience to Trauma and Degeneration

Cannabinoids are neuroprotective, meaning that they help maintain and regulate brain health. The effects appear to be related to several actions they have on the brain, including the removal of damaged cells and the improved efficiency of mitochondria. CBD and other antioxidant compounds in cannabis also work to reduce glutamate toxicity. Extra glutamate, which stimulates nerve cells in the brain to fire, causes cells to become over-stimulated, ultimately leading to cell damage or death. Thus, cannabinoids help protect brain cells from damage, keeping the organ healthy and functioning properly. CBD has also been shown to have an anti-inflammatory effect on the brain.

5. Protects against Bone Disease and Broken Bones

Cannabinoids are facilitative of the process of bone metabolism—the cycle in which old bone material is replaced by new at a rate of about 10 percent per year, crucial to maintaining strong, healthy bones over time. CBD in particular has been shown to block an enzyme that destroys bone-building compounds in the body, reducing the risk of age-related bone diseases like osteoporosis and osteoarthritis. In both of those diseases, the body is no longer creating new bone and cartilage cells. CBD helps spur the process of new bone-cell formation, which is why it has been found to speed the healing of broken bones and, due to a stronger fracture callus, decrease the likelihood of re-fracturing the bone (bones are 35–50 percent stronger than those of non-treated subjects).

6. Protects and Heals the Skin

The skin has the highest amount and concentration of CB2 receptors in the body. When applied topically as an infused lotion, serum, oil, or salve, the antioxidant (a more powerful antioxidant than vitamins E and C) in CBD oil has many benefits and can repair damage from free radicals like UV rays and environmental pollutants. Cannabinoid receptors can be found in the skin and seem to be connected to the regulation of oil production in the sebaceous glands. Cannabis-based topical products are being developed to treat related issues from acne to psoriasis and can promote faster healing of damaged skin.

In fact, historical documents show that cannabis preparations have been used for wound healing in both animals and people in a range of cultures spanning the globe and going back thousands of years. The use of concentrated cannabis and CBD oils to benefit and treat skin cancer is gaining popularity with a number of well-documented cases of people curing both melanoma and carcinoma-type skin cancers with the topical application of CBD and THC products. The best known of these is the case of Rick Simpson, who cured his basal cell carcinoma with cannabis oil and now has a widely distributed line of products. Cannabis applied topically is not psychoactive.

8. Anxiety and Stress

The oral use of cannabis and CBD for anxiety appears in a Vedic text dated around 2000 BCE,[238] and it is one of the most common uses of the plant across various cultures. While THC can increase anxiety in some patients, it lowers it in others. However, CBD effects have been shown to consistently reduce anxiety when present in higher concentrations in the cannabis plant. On its own, CBD has been shown in a number of animal and human studies to lessen anxiety. The stress-reducing effect appears to be related to activity in both the limbic and paralimbic brain areas.

A 2012 research review assessed a number of international studies and concluded that CBD has been shown to reduce anxiety, and in particular social anxiety, in multiple studies and called for more clinical trials. Two years later, researchers in an animal study related to stress and the endocannabinoid system wrote that augmentation of the endocannabinoid system might be an effective strategy to mitigate behavioral and physical consequences of stress.

In addition to elucidating the relationship between CBD and anxiety, these findings appear to support that the anxiolytic effect of chronic CBD administration in stressed mice depends on its proneurogenic action in the adult hippocampus by facilitating endocannabinoid-mediated signaling.

9. Depression and Mood Disorders

Clinical depression is a serious mood disorder characterized by persistent sadness and loss of interest, sometimes leading to decreased appetite and energy and suicidal thoughts. Commonly used pharmaceuticals for depression often target serotonin, a chemical messenger that is believed to act as a mood stabilizer. The neural network of the endocannabinoid system works similarly to the way that serotonin, dopamine, and other systems do, and, according to some research, cannabinoids have an effect on serotonin levels. Whereas a low dose of THC increases serotonin, high doses cause a decrease that could worsen the condition. In 2009 researchers concluded that there was substantial evidence pointing to endocannabinoid signaling as a target for the pharmacotherapy of depression. Authors of a 2016 study wrote that “CBD could represent a novel fast antidepressant drug, via enhancing both serotonergic and glutamate cortical signaling through a 5-HT1A receptor-dependent mechanism.

CBD might especially be effective for depression related to chronic stress, which has been shown to cause a decrease in endocannabinoid levels.

Effectiveness: Current Science—CBD Benefits for Depression

The Cannabis Health Index (CHI) is an evidence-based scoring system for cannabis (in general, not just CBD effects) and its effectiveness on various health issues based on currently available research data. Refer to cannabishealthindex.com for updated information. Using this rubric and based on twenty-one studies, cannabis rated in the possible-to-probable range of efficacy for treatment of depression.

Research in 2005 called for clinical trials to look into the effectiveness of cannabinoids for bipolar disorder (manic depression). In 2010, a study suggested that CBD was not useful for the manic episodes associated with bipolar disorder.[318] However, for depressive episodes, the evidence points to greater potential for effectiveness.

Authors of a 2013 review of animal studies wrote that CBD showed antianxiety and antidepressant effects in several models and suggested that the compound worked by interacting with the 5-HT1A neuroreceptor.

“It is important to remember that CBD benefits and improves the activity in the endocannabinoid system by increasing the time anandamide works on the CB1 and CB2 receptors,” writes Dr. Michael Moskowitz. “Anandamide works on the serotonin, norepinephrine, and dopamine systems. It also works on the GABA-glutamate system and the hypothalamic-pituitary-adrenal axis. Its main role is restoring balance through inhibition when levels are too high and enhancement when they are too low. This is the most likely reason phytocannabinoids in general and CBD specifically are able to regulate depression and anxiety.

Of all the reasons that people use CBD today, pain is the most common. The same can be said of cannabis in general. In the United States, over seventy million people suffer from chronic pain, which is defined as experiencing over one hundred days per year of pain. Physicians differentiate between neuropathic (usually chronic) and nociceptive pains (usually time-limited), and cannabis works on most neuropathic and many nociceptive types of pain. A number of studies have demonstrated that the endocannabinoid system is both centrally and peripherally involved in the processing of pain signals.[383] Most discussions of using CBD for pain treatment suggest that finding the right dosage is critical.

Cannabinoids can be used along with opioid medications, and a number of studies have demonstrated that they can reduce the amount of opioids needed, lessen the buildup of tolerance, and reduce the severity of withdrawal. At least ten randomized, controlled trials on over one thousand patients have demonstrated efficacy of cannabinoids for neuropathic pain of various origins.

Effectiveness: Current Science—CBD Benefits for Pain

The Cannabis Health Index (CHI) is an evidence-based scoring system for cannabis (in general, not just CBD effects) and its effectiveness on various health issues based on currently available research data. Refer to cannabishealthindex.com for updated information and more about studies related to specific types of pain. Considering all of the studies together, which number over forty (for various types of pain), CBD and cannabis are shown to have a rating of likely probable efficacy. It is one of the best-substantiated medical uses of cannabinoids.

Sativex, a cannabis plant–derived oromucosal spray containing equal proportions of THC and CBD, has been approved in a number of countries for use to treat specific types of pain. Numerous randomized clinical trials have demonstrated the safety and efficacy of Sativex for treatment of central and peripheral neuropathic pain, rheumatoid arthritis, and cancer pain.

Cannabinoids affect the transmission of pain signals from the affected region to the brain (ascending) and from the brain to the affected region (descending). A 2011 study showed that CBD and CBC stimulated descending pain-blocking pathways in the nervous system and caused analgesia by interacting with several target proteins involved in nociceptive control. Authors concluded that the cannabinoids “might represent useful therapeutic agents with multiple mechanisms of action.” [387] The following year, researchers reported that CBD significantly suppressed chronic inflammatory and neuropathic pain without causing apparent analgesic tolerance in animals.  And then in 2013, researchers concluded that chronic pain patients prescribed hydrocodone were less likely to take the painkiller if they used cannabis.

11. Sleep Disorders (Insomnia, Sleep Apnea)

Cannabis and sleep have a complex relationship that is only beginning to be understood by science. In general, for most people, indica strains are more relaxing and effective for sleep disorders, whereas sativa strains are more stimulating and tend to keep people awake.

Several studies conducted between 2004 and 2008 demonstrated the variable effect of different cannabinoids on sleep. In one, 15 mg of THC appeared to have sedative properties, while 15 mg of CBD appeared to have alerting properties.[416] Another tested the effects of CBD on animal models in both lights-on and lights-off environments and found that this non-psychoactive cannabis compound increased alertness with the lights on and had no discernable effects on lights-off sleep. The study’s authors concluded that CBD might actually hold therapeutic promise for those with somnolence, or excessive daytime sleepiness from a not-so-good night’s rest. Another study found CBD to be wake-inducing for most subjects, though some reported better sleep a few hours after taking it.

“Many of my patients report either better energy or sleepiness on the same high-CBD/low-THC plants,” Dr. Michael Moskowitz reported. “Most, however, feel more energy on high-CBD cannabis.

In general, indica varieties of THC appear to work best as a sleep aid for most people. However, a significant number of people find THC, even indica strains, will make the mind more active. For these people, CBD oil can benefit them and tends to work well, providing the relaxation and calm for the mental as well as the physical body. For these people, CBD taken at nighttime as part of a bedtime regime produces a restful sleep, not the alertness produced in the daytime. This bidirectional effect of CBD is the result of balancing the endocannabinoid system.

In relation to sleep apnea, a 2002 animal study observed the ability of THC to restore respiratory stability by modulating serotonin signaling and reducing spontaneous sleep-disordered breathing. In 2013 a trial using the pharmaceutical drug dronabinol, a synthetic THC mimic, noted improvements in fifteen out of seventeen study participants following twenty-one days of treatment.

Effectiveness: Current Science—CBD Benefits for Sleep Disorders

The Cannabis Health Index (CHI) is an evidence-based scoring system for cannabis (in general, not just CBD oil effects) and its effectiveness on various health issues based on currently available research data. Refer to cannabishealthindex.com for updated information. Using this rubric, the use of cannabis-based products for treating insomnia has a rating of likely probable efficacy based on the four studies available at press time (3.4 points).

A 2007 study with the pharmaceutical 1:1 CBD:THC spray showed good results in helping patients with chronic pain sleep better. REM sleep behavior disorder (RBD) is characterized by the loss of complete muscle relaxation during REM sleep, associated with nightmares and physical activity during dreaming. Four patients in a case series treated with CBD in 2014 had prompt and substantial reduction in the frequency of RBD-related events without side effects.

This article is excerpted with permission from CBD: A Patient’s Guide to Medicinal Cannabis—Healing without the High by Leonard Leinow and Juliana Birnbaum.