This review discusses the rationale and experimental data that led to clinical trials of certain botanical lipids, mainly gammalinolenic acid (GLA), for the treatment of rheumatoid arthritis (RA).
Pertinent articles and reviews, and a bibliographic database in English using the following indexing terms: rheumatoid arthritis, fatty acids, gammalinolenic acid, lymphocytes, and monocytes, were used.
All clinical trials in which GLA was used to treat arthritis are included in this review. Data from appropriately peer reviewed in vitro and animal experiments evaluating the effects of botanical lipids as regulators of cell activation and immune responses are also reviewed.
GLA treatment is associated with clinical improvement in patients with RA, as evaluated by duration of morning stiffness, joint pain and swelling, and ability to reduce other medications. However, studies vary in terms of duration, GLA dose, whether or not they were placebo controlled, and, if so, what placebo was used, criteria for evaluation, and use of concomitant medication. Studies done in vitro generally indicated that GLA reduces lymphocyte activation and production of mediators of inflammation.
A small number of studies suggest that GLA is effective treatment for RA patients. Further controlled studies of its use in RA seem warranted.