Effects of altering dietary essential fatty acids on requirements for non-steroidal anti-inflammatory drugs in patients with rheumatoid arthritis: a double blind placebo controlled study.
In rheumatoid arthritis (RA) benefit from non-steroidal anti-inflammatory drugs (NSAIDs) is mediated through inhibition of the cyclo-oxygenase enzyme, thereby decreasing production of the 2 series prostaglandins (PGs). The lipoxygenase enzyme is intact, however, allowing leucotriene (LT) production, e.g., LTB4 (an inflammatory mediator). Treatment with evening primrose oil (EPO) which contains gamma-linolenic acid (GLA) leads to production of the 1 series PGs, e.g., PGE1, which has less inflammatory effects. Also LT production is inhibited. Eicosapentaenoic acid (EPA, fish oil) treatment provides a substrate for PGs and LTs, which are also less inflammatory. In this study 16 patients with RA were given 540 mg GLA/day (EPO), 15 patients 240 mg EPA and 450 mg GLA/day (EPO/fish oil), and 18 patients an inert oil (placebo). The aim of this study was to determine if EPO or EPO/fish oil could replace NSAID treatment in RA. The initial 12 month treatment period was followed by three months of placebo for all groups. Results at 12 months showed a significant subjective improvement for EPO and EPO/fish oil compared with placebo. In addition, by 12 months the patients receiving EPO and EPO/fish oil had significantly reduced their NSAIDs. After 3 months of placebo those receiving active treatment had relapsed. Despite the decrease in NSAIDs, measures of disease activity did not worsen. It is suggested that EPO and EPO/fish oil produce a subjective improvement and allow some patients to reduce or stop treatment with NSAIDs. There is, however, no evidence that they act as disease modifying agents.
Belch
J J
JJ
Centre for Rheumatic Diseases, University Department of Medicine, Royal Infirmary.
Ansell
D
D
Madhok
R
R
O'Dowd
A
A
Sturrock
R D
RD
D000328:Adult; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D015118:Eicosapentaenoic Acid / Q000627:therapeutic use*; D005228:Fatty Acids, Essential / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008041:Linoleic Acids; D008297:Male; D008875:Middle Aged; D031665:Oenothera biennis; D010938:Plant Oils; D011897:Random Allocation; D017965:gamma-Linolenic Acid
D000894:Anti-Inflammatory Agents, Non-Steroidal; D005228:Fatty Acids, Essential; D008041:Linoleic Acids; D010938:Plant Oils; C028498:evening primrose oil; D017965:gamma-Linolenic Acid; D015118:Eicosapentaenoic Acid