A review found emerging but insufficient evidence for cannabinoids in treating rheumatic diseases | Research

The takeaway

A Nature Reviews Rheumatology article reviewed preliminary clinical trials on cannabis for rheumatoid arthritis, osteoarthritis, and fibromyalgia, concluding that while cannabinoids show immunomodulatory potential, evidence is not yet sufficient to recommend them for rheumatic diseases.

Rheumatologists counseling patients about cannabis; medical cannabis patients with arthritis or fibromyalgia; researchers studying cannabinoid immunology.

Evidence is not yet sufficient to recommend cannabinoids for rheumatic diseases

What the researchers found

Researchers reviewed the available evidence on cannabinoids for rheumatic diseases.

Preliminary clinical trials have explored cannabis effects on rheumatoid arthritis, osteoarthritis, and fibromyalgia. Additional preclinical evidence links the cannabinoid system to systemic sclerosis and juvenile idiopathic arthritis.

Cannabinoids exert immunomodulatory effects on multiple immune cell types including T cells, B cells, and macrophages, which is theoretically relevant to autoimmune rheumatic conditions.

Pain is considered a prevalent indication for medicinal cannabis in countries where it is legal, and rheumatic disease pain is a common reason patients seek cannabis.

However, the authors concluded that available evidence is not sufficient to support recommending cannabinoid treatment for rheumatic diseases, calling for more rigorous research.

Why it matters

Rheumatic disease patients are among the most common users of medical cannabis for pain, yet rheumatologists have limited evidence to guide them. This high-profile review from a top rheumatology journal summarizes what is and is not known.

The numbers in context

Preliminary trials covered rheumatoid arthritis, osteoarthritis, and fibromyalgia. Immunomodulatory effects documented on T cells, B cells, and macrophages. Associations noted with systemic sclerosis and juvenile idiopathic arthritis.

How the study worked

Narrative review published in Nature Reviews Rheumatology covering clinical trials, preclinical studies, and immunological research on cannabinoids in rheumatic disease contexts.

What this study cannot tell us

Narrative review rather than systematic review. Available primary studies are small, few, and methodologically limited. The authors acknowledge that evidence is insufficient for clinical recommendations.

How to read the evidence

Moderate. Published in a top specialty journal with thorough coverage, but reflects the preliminary state of the underlying evidence.

When this study was published

Published in 2018 in Nature Reviews Rheumatology. Research on cannabinoids for inflammatory and autoimmune conditions has continued to develop.

The bigger picture

The gap between patient demand for cannabis-based rheumatic disease treatment and the available evidence base is a recurring theme in medical cannabis research. Patients are using cannabis for these conditions regardless of whether sufficient evidence exists.

Questions still open

Which specific cannabinoids and formulations would be most appropriate for different rheumatic conditions? Can cannabinoid immunomodulation be harnessed without psychoactive side effects? Do topical cannabinoid applications work for localized joint pain?

Common questions

Can cannabis help with arthritis pain?

Some patients report pain relief from cannabis, and preliminary trials have explored this. However, as of this 2018 review, the evidence was not strong enough for rheumatologists to formally recommend cannabis for arthritis. The immunomodulatory properties of cannabinoids are theoretically promising but need more rigorous study.

How do cannabinoids affect the immune system?

Cannabinoids interact with CB1 and CB2 receptors found on immune cells including T cells, B cells, and macrophages. This can modulate inflammatory responses, which is relevant to autoimmune conditions like rheumatoid arthritis. However, the clinical significance of these effects in treating disease is not yet established.

Read the original research

Cannabinoids for the treatment of rheumatic diseases - where do we stand?

Nature reviews. Rheumatology, 14(8), 488-498

View on PubMed ↗Publisher’s paper ↗

Citation

Katz-Talmor, Daphna; Katz, Itay; Porat-Katz, Bat-Sheva; Shoenfeld, Yehuda. (2018). Cannabinoids for the treatment of rheumatic diseases - where do we stand?. Nature reviews. Rheumatology, 14(8), 488-498. https://doi.org/10.1038/s41584-018-0025-5