n-3 PUFAs may protect against AF

31 January 2012

MedWire News: Dietary long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs) could be beneficial for the prevention of atrial fibrillation (AF) onset in older adults, suggest study findings.

Dariush Mozaffarian (Brigham and Women's Hospital, Boston, Massachusetts, USA) and co-authors found that higher circulating total long-chain n-3 PUFA and docosahexaenoic acid (DHA) levels were significantly associated with lower risk for incident AF.

In their study, the researchers investigated the association between biomarker levels of n-3 PUFAs and incident AF in over 3000 men and women aged 65 years or older who were free of AF or heart failure at baseline.

“Biomarker concentrations of n-3 PUFA, for example in circulating phospholipids, provide objective measures of exposure, incorporating influences of dietary intake as well as other potential physiologically relevant processes such as absorption, membrane incorporation, or metabolism,” explain the authors.

“Measurement of biomarkers has the additional advantage of allowing direct quantification of individual n-3 PUFA, including eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and DHA,” they add.

At baseline, the mean age was 74.1 years and 60% of participants were women. The mean total n-3 PUFA concentration was 4.5% of plasma phospholipid fatty acids, including DHA (3.0%), DPA (0.83%), and EPA (0.58%).

During 31,169 person–years of follow up, 789 incident cases of AF occurred.

Total n-3 PUFA levels were inversely associated with incident AF, with risk being 29% lower among participants in the highest compared with the lowest quartile.

When each individual n-3 PUFAs were examined separately, DHA was significantly associated with a lower risk for AF; those in the highest quartile had a 23% lower risk than those in the lowest quartile. EPA and DPA levels were not significantly associated with incident AF, however.

Of note, adjustment for intervening events, such as heart failure or myocardial infarction during follow-up did not appreciably alter the results, write Mozaffarian et al in Circulation.

“Given the aging of the population, the significant and growing public health burden of AF, and the limited treatment options once AF develops, our results highlight the need to investigate atrial physiological and arrhythmic mechanisms affected by total and individual n-3 PUFA, and to test the efficacy of n-3 PUFA for preventing new onset of AF among older adults in a randomized intervention,” they conclude.

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Circulation 2012; Advance online publication