SAN FRANCISCO, CA—Dietary omega-3 fatty acid-rich fish consumption, but not omega-3 supplements alone, appear to confer a protective effect against recurrent gout attacks, reported MaryAnn Zhang, MD, from the Boston University School of Medicine, in Boston, MA, at the 2015 ACR/ARHP Annual Meeting.
“Dietary omega-3 fatty acid from fatty fish was associated with a lower risk of recurrent gout attacks,” Dr. Zhang said. “Supplemental omega-3 fatty acid alone appeared not to have a protective effect, though we were limited in our ability to adequately assess this.”
“Consumption of specific sources of omega-3 polyunsaturated fatty acid for gout flare prevention warrants further study in an adequately powered clinical trial,” concluded Dr. Zhang. “Omega-3-to-omega-6 ratios should be taken into consideration,” she added, noting that, in contrast to omega-3 fatty acids’ anti-inflammatory effects, omega-6 fatty acids can have pro-inflammatory effects.
Guidelines for the management of gout currently recommend limiting the intake of high-purine fish.
Fatty fish containing omega-3 polyunsaturated fatty acids have demonstrated various anti-inflammatory effects, including decreased NSAID consumption, morning stiffness, and tender joint counts in rheumatoid arthritis, Dr. Zhang said. Omega-3 polyunsaturated fatty acids are known to suppress activation of the NLRP3 inflammasome in vitro in macrophages, and limit experimental IL-1 beta-mediated inflammatory responses in vivo.
Dr. Zhang and her colleagues assessed whether omega-3 polyunsaturated fatty acids was linked to a decrease in acute gout flares using self-reported data from 724 participants recruited online for the Boston University Online Gout Study (2003–2012). All study subjects documented at least 1 gout attack in the prior year with diagnosis confirmed by medical record view.
Participants logged the times of gout attacks (hazard periods) and every 3 months for 1 year during gout flare-free periods (control periods) to complete questionnaires about various exposures (eg, OTC medications, supplements, diet) during the 24- and 48 hours prior to the attack or control period. Specifically, researchers examined the association of omega-3 polyunsaturated fatty acid rich supplements and fish intake in the prior 48 hours. Risk of recurrent gout attacks was adjusted for alcohol and total purine intake, and urate-lowering or flare prophylactic drugs (eg, allopurinol, NSAIDs, and colchicine).
In the 48 hours prior to gout attacks, 22% of participants reported some form of omega-3 polyunsaturated fatty acid consumption, of which 4.6% stated use of omega-3 supplements (eg, fish oil, omega-3 or cod liver oil supplements) and 19% reported dietary fish consumption, including anchovies, mackerel, salmon, sardines, cod, trout, herring, tuna or squid, Dr. Zhang said.
For all 3 omega-3 supplement types combined, the adjusted odds ratio was 1.01 (95% CI: 0.63–1.60) and 0.77 (95% CI: 0.61–0.96; P=0.02) for consumption of at least 1 omega-3 polyunsaturated fatty acid-rich fish servings.
“In a sensitivity analysis, we assessed the effects of other foods with different degrees of omega-3-to-omega-6 ratios,” Dr. Zhang said.
Whereas omega-3-rich fatty fish consumption had a protective effect against gout flares, foods like spinach that have equal levels of omega-3 and omega-6 fatty acids had no effect on gout flare risk–and foods like eggs that have a low omega-3-to-omega-6 fatty acid ratio tended to increase the risk of gout flares (for 2 or more servings, adjusted OR 1.34; 95% CI: 1.10–1.63), Dr. Zhang and her colleagues found.
Study limitations included relatively few participants’ reporting any supplemental omega-3 fatty acid use, possibly resulting in too few discordant pairs for precise analysis, Dr. Zhang cautioned. “Dosing of omega-3 fatty acid sources was not known and there may have been insufficient exposure distribution,” she added.