A recent study published in The American Journal of Clinical Nutrition determined whether marine omega-3 fatty acid (FA) consumption increases atrial fibrillation (AF) risk amongst United States military veterans.

Study: Dietary ω-3 fatty acids and the incidence of atrial fibrillation within the Million Veteran Program. Image Credit: Natali _ Mis / Shutterstock.com

Background

AF, essentially the most incessantly sustained cardiovascular arrhythmia, is extremely prevalent within the US and may increase the burden on healthcare facilities. Marine omega-3 FA, equivalent to eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and docosapentaenoic acid (DPA), are primarily consumed amongst US residents through seafood.

Recent large-scale randomized clinical trials (RCTs) evaluating the impact of DHA and EPA dietary supplementation on the cardiovascular system have documented increased AF risks following DHA and EPA consumption. Nonetheless, scientific evidence on the link between omega-3 FA intake and AF risk is inconsistent, thus warranting further research.

In regards to the study

The current study assesses the association between omega-3 FA intake and AF amongst US veterans.

By December 2020, 819,417 veteran individuals participated in the possible cohort MVP study, provided serum samples, and accomplished food frequency questionnaires (FFQs). Among the many participants, 379,852 individuals accomplished the Lifestyle Survey to supply data on their dietary habits, amongst whom those with a positive history of AF were excluded from the current evaluation.

AF was determined based on the International Classification of Diseases, ninth and tenth versions (ICD-9, -10) diagnostic codes mentioned within the veterans’ electronic medical records. Positive AF history was based on at the very least one or two diagnoses in inpatient and outpatient settings before the tip of the follow-up period. The mean each day calorie intake of various foods was calculated, following which omega-3 FA consumption was determined using the Harvard University Food Composition Database data.

Multivariate Cox proportional-type hazards regression modeling was performed to find out the hazard ratios (HRs) of AF across quintiles of omega-3 FA intake, adjusting for covariates equivalent to age, gender, body mass index (BMI), ethnicity, race, educational attainment, income, smoking habits, physical exertion, alcohol consumption, nutrient intake, and comorbidities equivalent to coronary artery diseases, heart failure, diabetes, chronic renal disease, and hypertension.

A restricted-type cubic spline evaluation was also performed to guage the dose-dependent relationships between AF and omega-3 FA. A secondary evaluation determined the connection between dietary omega-3 FA intake and AF risk.

Data were obtained until AF occurrence, death, date of essentially the most recent update within the electronic medical records, or September 30, 2020, within the case of essentially the most recent health visit reported within the electronic medical record on or after October 1, 2020.

Study findings

Among the many 301,294 participants, the mean age was 65 years, 91% were male, and 84% were White. The median omega-3 FA consumption was 219 mg each day.

Higher marine omega-3 FA intake was positively related to physical exertion, hypertension, coronary artery diseases, college-level education, and an annual household income above $60,000 USD. In contrast, higher omega-3 FA intake was negatively related to alcohol consumption, smoking habits, highschool or a lower level of education, and an annual income below $30,000 USD.

Omega-3 FA intake showed a non-linear inverse association with new-onset AF. It was characterised by an initial reduction to 11% after consuming 750 mg each day of marine omega-3 FA, followed by a plateau.

The current study findings contradicted those of the REDUCE-IT and STRENGTH clinical trials, through which the participants consumed 4,000 mg of omega-3 FA each day, which indicates that omega-3 FA can have dose-dependent effects.

Moreover, the REDUCE-IT trial included individuals with diabetes, cardiovascular diseases, or elevated triglyceride (TG) levels requiring statin therapy. Likewise, the STRENGTH trial included individuals with increased TG and high-density lipoprotein (HDL) levels, elevated risks of heart problems, and statin use. These inclusion criteria didn’t apply to the present study cohort.

Conclusions

Marine and dietary omega-3 FA consumption lowered AF risk non-linearly; nevertheless, additional studies that include individuals of various ages, races, and ethnicities, more female representation, and multiple FFQs to evaluate dietary changes over time, are needed to enhance the generalizability of the study findings. Future studies may use objective patient-level information, equivalent to electrocardiograms (ECGs), to capture more atrial fibrillation episodes.