F 2 ‐isoprostanes are prostaglandin‐like compounds derived from free radical‐catalysed peroxidation of arachidonic acid. Peroxidation of eicosapentaenoic acid produces F 3 ‐isoprostanes, whereas peroxidation of docosahexaenoic acid would give F 4 ‐isoprostanes. This study demonstrates the presenc…