Dietary Fatty Acids and Antinuclear Antibodies Among Adults with Arthritis in the United States: NHANES 1999–2004

<b>Background</b>: This study investigated the link between daily fatty acid intake and antinuclear antibody (ANA) levels, a marker of immune dysregulation and autoimmune diseases, in individuals with self-reported arthritis. <b>Methods</b>: From the US National Health and Nutrition Examination Survey (NHANES) 1999-2004, 829 participants who self-reported arthritis and had autoantibody measurements were selected. Dietary fatty acids were collected via two 24 h dietary recall interviews conducted by trained interviewers. ANA levels were collected by measuring IgG autoantibodies targeting cellular antigens. <b>Results</b>: In a multi-adjusted logistic model, the odds ratio (OR) of the highest tertile of omega-3 intake (with omega-3 intake > 1.60 g/day) for the probability of ANA positivity was 0.43 (95% CI: 0.19-0.96) compared to those in the lowest tertile (≤0.92 g/day). However, we did not observe statistically significant results for other fatty acids. <b>Conclusions</b>: Our findings highlight the potential of dietary omega-3 PUFAs to modulate immune function and lower the risk of ANA positivity in individuals with arthritis.