The relationship between omega-3 fatty acids and atrial fibrillation (AF) has been debated. 
 

The researchers of this study, Quian et al., investigated the prospective associations of blood or adipose tissue levels of the three bioactive fatty acids –docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), and eicosapentaenoic acid (EPA) - on the incidence of atrial fibrillation (AF).
 

Participant data from a global consortium of 17 prospective cohort studies was analysed. The following results were recorded:
 

• Of the 54,799 participants included in the study, 7,720 cases of AF were ascertained after a median of 13.3 years of follow-up
• Multivariable analysis of EPA levels showed they were not associated with incident AF
• The HR per interquartile range (i.e. the difference between the 90th and 10th percentiles) was 1.00 (95% CI: 0.95-1.05). 
• The  HRs for higher levels of DPA, DHA, and EPA & DHA were 0.89 (95% CI: 0.83-0.95), 0.90 (95% CI: 0.85-0.96), and 0.93 (95% CI: 0.87-0.99), respectively.

The researchers concluded there was no increased risk of developing atrial fibrillation associated with in vivo levels of omega-3 fatty acids, including EPA, DPA, DHA, and EPA and DHA. This finding supports the continuation of current dietary guidelines that recommend the consumption of fish and omega-3 fatty acids.