Omega-3 fatty acids have been considered anti-inflammatory lipids based on data from epidemiological studies of Greenland Eskimos whose diet is rich in fish, sources of polyunsaturated fatty acids.

Fatty acids from the omega-3 family [mainly the α-linolenic acid, eicosapentaenoic (EPA) and docosahexaenoic (DHA)], as well as those of the omega-6 family [represented mainly by linoleic acid and arachidonic acid (AA)] are essential for the synthesis of eicosanoids, prostaglandins, leukotrienes, thromboxanes and other oxidative factors, major mediators and regulators of inflammation.

Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease characterized by the loss of balance of cellular immunoregulation and increased levels of circulating inflammatory mediators.Thus, omega-3 supplementation could represent additional therapy for individuals with SLE.

The aim of this study was to investigate the effects of omega-3 fatty acids on circulating levels of inflammatory and biochemical markers in women with SLE.

This is a pilot clinical trial of omega-3-polyunsaturated fatty acids carried out in SLE patients followed at the Rheumatology Unit of Hospital das Clínicas, Universidade Federal de Minas Gerais, UFMG.

Female patients who met the revised American College of Rheumatology (ACR) classification criteria for SLE (1982/1997)15, age over 18 years old and below 60 years old, who were taking stable doses of medications for the SLE treatment in the last three months were included. Exclusion criteria were the following: pregnancy, disease duration of less than one year, allergy to fish, fish oil or any omega-3 product, omega-3 use within the previous six months and diagnosis of diabetes mellitus, liver disease, chronic renal failure, any type of infection at enrollment and/or throughout the study.

A 12 week pilot clinical trial of omega-3 fatty acid supplementation was conducted. Participants were seen at baseline (T0) and at week 12 (T1) for clinical, laboratory and nutritional assessment. Participants were also contacted by telephone in week 6 to check on compliance and any adverse events. The patients were randomized into one of two groups in a 1:1 ratio. Patients in the study group received, throughout 12 weeks, two tablets per day of omega-3 fatty acids (540mg of EPA and DHA of 100mg; Hiomega-3 supplement of Naturalis® company - registered in the National Health Department number 4.1480.0006.001-4). Patients in the control group did not receive the nutrient nor any kind of placebo. All participants were instructed not to take omega-3 rich foods during the study period. The researcher (FMMS) who did clinical assessment and the inflammatory and biochemical data assessment was blind to randomization and intervention.

Variables measured at each visit included: disease activity index, using the Systemic Lupus Disease Activity Index (SLEDAI-2k)16; damage index (Systemic Lupus International Collaboration Clinics/American College of Rheumatology damage index - SLICC/ACR)17; fasting lipid and glucose profile; standard laboratory tests to assess SLE (red and white blood count, platelet count, creatinine, urinalysis, urine protein/creatinine ratio, anti-dsDNA, anticardiolipin, C3 and C4 levels); cytokines (IL-6, IL-10), adipokines (leptin, adiponectin) C-reactive protein (CRP), nutritional assessment, and in use medications.

Inclusion Criteria: 1-Diagnosis of lupus according to American College of Rheumatology (ACR) classification criteria for SLE (1982/1997)

• Taking stable doses of medications for the SLE treatment in the last three months.

Exclusion Criteria:

• pregnancy, disease duration of less than one year, allergy to fish, fish oil or any omega-3 product, omega-3 use within the previous six months and diagnosis of diabetes mellitus, liver disease, chronic renal failure, any type of infection at enrollment and/or throughout the study