AALBORG, DENMARK. A low degree of heart rate variability (HRV) is a very strong predictor of sudden death among survivors of a heart attack (myocardial infarction). Danish researchers now report that a high fish consumption increases the concentration of n-3 polyunsaturated fatty acids (PUFAs) in cell membranes and that this increase is associated with a significant beneficial increase in HRV.
Their study involved 52 patients who had suffered a heart attack and had a left ventricular ejection fraction of 40 per cent or less. The researchers found that patients who ate fish once a week had an 18 per cent higher HRV than non-fish eaters. Fish eaters were also found to have a higher content of DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) in their blood platelets. Patients with more than 3.14 per cent DHA in their platelets were found to have a 43 per cent higher HRV than patients with a DHA content of less than 2.26 per cent. The researchers also discovered that a high ratio of arachidonic acid to DHA in the platelets corresponds to a significantly lower HRV. Other research has shown that the consumption of just one fatty fish meal per week reduces the risk of primary cardiac arrest by 50 per cent.
Hagstrup Christensen, Jeppe, et al. Fish consumption, n-3 fatty acids in cell membranes, and heart rate variability in survivors of myocardial infarction with left ventricular dysfunction. American Journal of Cardiology, Vol. 79, June 15, 1997, pp. 1670-73
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