N-3 fatty acids and cardiac autonomic function in humans.

Studies suggest that marine n-3 polyunsaturated fatty acids (PUFA) offer some protection against sudden cardiac death (SCD). The autonomic nervous system is involved in the pathogenesis of SCD and due to the fact that n-3 PUFA is abundant in the brain and other nervous tissue it is likely that n-3 PUFA might modulate autonomic control of the heart. Heart rate variability (HRV) is a non-invasive marker of cardiac autonomic function and an attenuated HRV is a predictor for SCD and arrhythmic events. Studies on HRV and n-3 PUFA have been performed in several populations such as patients with ischaemic heart disease, patients with diabetes mellitus, patients with chronic renal failure, and in healthy subjects. Many studies have demonstrated a positive association between cellular content of n-3 PUFA and HRV as well as supplementation with n-3 PUFA seems to increase HRV and thereby decreasing the risk of arrhythmic events and SCD.