Dietary Omega-3 Intake Shows No Overall Link to Atrial Fibrillation Biomarkers in Older Adults

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, increasing risks of stroke, heart failure, and mortality. Its pathogenesis involves complex pathways including inflammation, oxidative stress, and myocardial fibrosis. Current standard-of-care often focuses on rhythm control and anticoagulation, but lifestyle interventions are also explored. Omega-3 fatty acids, known for their anti-inflammatory and cardioprotective properties, have been hypothesized to modulate AF-related pathways. However, it remains unclear whether habitual dietary intake of omega-3s is sufficiently reflected in circulating biomarkers relevant to AF development and progression.

Researchers analyzed data from 510 older Spanish adults with metabolic syndrome participating in the PREDIMED-Plus trial. Participants' dietary omega-3 intake (total, marine-derived, non-marine-derived) was assessed using a validated 143-item food-frequency questionnaire. Circulating levels of five AF-related biomarkers—N-terminal pro-B-type natriuretic peptide (NT-pro-BNP), high-sensitivity troponin T (hs-TnT), high-sensitivity C-reactive protein (CRP), C-terminal propeptide of type-I procollagen (PICP), and 3-nitrotyrosine (3-NT)—were measured at baseline, 3 years, and 5 years. Cross-sectional and longitudinal associations between omega-3 intake tertiles and biomarker trajectories were estimated using linear regression and mixed-effects models.

The median total omega-3 intake among participants was 2.0 g/day. Overall, total habitual omega-3 fatty acid intake demonstrated no significant association with any of the measured AF-related biomarkers, neither in cross-sectional analyses nor over the 5-year longitudinal follow-up. This suggests that general dietary omega-3 consumption may not broadly influence these specific circulating markers of AF pathways. However, some isolated findings emerged:

Marine omega-3 intake was directly associated cross-sectionally with 3-NT (a marker of oxidative stress), showing a +28.4% increase in the highest versus lowest tertile (95% CI 5.5 to 56.2; p-trend = 0.014). This association was not sustained longitudinally. Additionally, moderate baseline non-marine omega-3 fatty acid intake was associated with a decrease in PICP (a marker of collagen synthesis and fibrosis) after 5 years of follow-up, indicating a potential, albeit non-linear, effect on myocardial remodeling. These specific associations warrant further investigation due to their sporadic nature.