The role of omega‐3 polyunsaturated fatty acid‐enriched diets in the prevention of ventricular fibrillation

Abstract

In a number of epidemiological surveys and in two recent intervention trials in cardiac patients, diets rich in marine omega-3 polyunsaturated fatty acids (PUFA), which include both eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been found to be beneficial in reducing the susceptibility of developing serious ventricular fibrillation (VF) or malignant cardiac dysrhythmia and mortality from sudden cardiac death (SCD). In addition to this information from human studies, there is strong supporting evidence from laboratory experiments utilizing the small non-human primate marmoset monkey (Callithrix jacchus). For example, a diet enriched with tuna fish oil that is high in both DHA and EPA has been found to increase the electrical threshold current necessary for inducing VF and to reduce mortality to zero in marmoset monkeys with experimentally induced ischaemic cardiac dysrhythmia (ICH). From these and earlier studies in other animals there is also some evidence which suggests that it may be the DHA rather than the EPA component of fish oils which is the biologically active fatty acid responsible for the reduction in susceptibility of developing VF and ICH. If this possibility could be determined with confidence, it would greatly assist in the design of future intervention trials, which are required in order to determine both the nature and amount of dietary omega-3 PUFA that is necessary to achieve these beneficial effects. Any simple dietary strategy that could lead to a substantial decrease in VF and mortality from SCD would be of great medical, social and economic benefit.

The impact of long-chainn-3 polyunsaturated fatty acids on human health

“…It has been suggested that LC n-3 PUFA affect the electrophysiological function of cardiac myocytes in such a way as to reduce their vulnerability to fibrillation (Charnock, 1999; for a review of anti-arrhythmogenesis operating via Na channel proteins, see Das, 2000).…”

The impact of cheese consumption on markers of cardiovascular risk in rats

“…The long-chain fatty acids (carbon chain length X20) were assessed as the metabolic products of the dietary components provided, e.g., 18 carbon chain length fatty acids provided by canola oil. The long-chain fatty acids considered optimal for health are the o3 series-eicosapentanoic (20:5) and docosahexanoic (22:6) forms, which have been found to be associated with significantly lower cardiovascular and sudden myocardial infarction risks (Charnock, 1999;McLennan et al, 1996;Mori & Beilin, 2001;Simopoulos, 1991). These significant fatty acids for eicosanoid production were well represented relative to the arachidonic acid (20:4) levels in the cheese-fed group (diet 1).…”

Clinicians changing individual food habits

“…26 Much evidence points to this risk being reduced by fish intakes of as little as one to three meals a week. 27 For those who are vegetarian or cannot eat fish because of sensitivity reactions, alternative plant sources of n-3 fatty acids may be important; these include linseed, rapeseed (sometimes known as Canola), purslane and, to some extent, soy.…”