Usefulness of plasma phospholipid N-3 fatty acid levels in predicting dietary fish intake in patients with coronary artery disease

An association between decreased cardiovascular mortality and high dietary fish intake 1,5 has suggested a possible protective role for n-3 fatty acids against the development of coronary artery disease (CAD). An inverse relation has also been observed between the risk of CAD and eicosapentaenoic acid (EPA) levels in various tissues. 6–10 A reasonable but unproven assumption is that tissue levels of n-3 fatty acids correlate with dietary fish intake. To test this assumption, we investigated whether a relation exists between quantity of chronic fish consumption and levels of n-3 fatty acids in plasma phospholipids, using a previously validated food frequency questionnaire. 11 Plasma phospholipids were chosen because they are the plasma lipids least sensitive to changes in short-term dietary fat intake. 12,13 Patients with established CAD were chosen because they are the group in which n-3 fatty acid levels have been most intensively studied.