In a recent study published in the Journal of Cannabis Research, researchers conducted an open-label pilot study to determine the efficacy and tolerability of cannabidiol (CBD) as a potential pain management therapy in a group of former elite athletes with chronic levels of pain in the lower extremities.

Background

Of the two main cannabinoids of interest in Cannabis, delta-9-tetrahydrocannabinol and CBD, CBD has received significant interest in the field of medical research as it possesses various therapeutic properties while not being a psychoactive compound and, therefore, reducing the danger of addiction or misuse.

Studies have shown that among patients with rheumatoid arthritis, osteoarthritis, and musculoskeletal pain in the lower extremities, CBD use in the form of a topical application or oral tincture is prevalent.

However, there is a paucity of studies examining the efficacy and tolerability of the therapeutic use of CBD for chronic pain, and the few studies that have examined the efficacy of CBD in treating pain in patients with lower extremity symptomatic peripheral neuropathy have reported mixed results.

Given the removal of CBD from the substances prohibited for use in sports, a growing number of athletes have been using topical CBD since it reduces systemic exposure. Since athletes are more attuned to recognizing changes in physical health, and athletes involved in sports such as track and field, American football, and basketball are vulnerable to injuries in the lower extremities, they provide an ideal group to assess the efficacy and tolerability of the therapeutic use of CBD.

About the study

In the present study, the participants were former professional athletes comprising male American football players, male and female track and field athletes, and female basketball players with a career in sports spanning four to 10 years. Only those athletes who had sustained an acute injury causing pain in the lower extremities for at least three months were included in the study.

All athletes had undergone various forms of treatments, including chiropractors, athletic trainers, massage therapists, visits to doctors, surgery, and medications comprising acetaminophen, non-steroidal anti-inflammatory drugs, and opioids.

All treatments were discontinued before the study. Participants were administered two daily applications of a topical formulation consisting of 10 mg of the active ingredient CBD and other compounds such as camphor, ylang-ylang, lemongrass, and wintergreen essential oils.

Topical formulations are preferred by athletes as they do not result in systemic delivery unless enhanced to improve permeation. Compounds with moderate lipophilicity achieve better systemic delivery, and phytocannabinoids such as CBD are highly lipophilic, which causes limited permeation through the skin. This high lipophilicity also causes CBD to accumulate in the skin, causing irritation, xerosis, and skin erythema.

The efficacy assessments were based on the Pain Disability Index (PDI) which is used to determine the degree to which the pain impacts the individual’s daily. Self-reported measures of the impairment of activity in different functional domains of life due to the pain were also used to evaluate the efficacy of the treatment.

Results

The results indicated that CBD treatment for lower extremity pain did not result in serious adverse reactions requiring medical attention. While 30% of the participants reported experiencing minor adverse reactions that did not impair their ability to complete the study, the remaining 70% tolerated the treatment and did not experience any detrimental reactions to the CBD treatment. Skin dryness and rash were the two most commonly reported side effects.

The study also showed that self-reported pain levels improved significantly with decreased pain-related disabilities in various domains such as life support activities, recreational activities, responsibilities related to the home and family, sexual function, self-care, and social activities.

In the domains of sexual function and responsibilities to the home and family, all the participants reported experiencing improvements after treatment with topical CBD. Furthermore, 93% of the participants experienced improvements after CBD treatment in areas involving social, recreational, occupational, and life support activities, while 83% indicated improvements in self-care-related activities.

The authors mentioned that while the exact mechanism of CBD action remains unclear, CBD does not seem to interact directly with the cannabinoid receptors and mitigates joint pain symptoms through anti-inflammatory effects.

Conclusions

Overall, the findings reported that treatment with a topical formulation containing CBD was well-tolerated in male and female athletes experiencing chronic pain in the lower extremities. Furthermore, the treatment significantly improved self-reported pain levels and disabilities in various domains of life. The results of this pilot study suggested that further controlled trials to evaluate the efficacy of topical CBD for pain relief are warranted.