The study was complicated, however, by the very high background intake of both EPA and DHA, which is estimated to be between 800 and 1000 mg/d in the adult Japanese population (18). Thus, the application of these findings to Western populations consuming lower amounts of n−3 FAs is not clear. In addition, the authors did not measure the omega-3 index in this study (only serum concentrations of EPA), so the relations between the index and risk cannot be directly ascertained.