Personal reflections on the incidence of ischaemic heart disease in Oslo during the Second World War.

The dietary changes in Norway and especially in Oslo during the Second World War, with reduced fat intake and increased consumption of fish and fish products, was paralleled by a reduced incidence of and mortality from IHD. This was probably caused to a high degree by reduced platelet aggregability leading to a reduced tendency to thrombosis. We suggest that the mechanism behind this reduction was a changed balance between pro- and anti-aggregatory prostaglandins towards the anti-aggregatory side, caused by eicosapentaenoic acid from fish lipids. Furthermore, hypocholesterolaemia due to reduced fat intake and increased consumption of polyunsaturated fatty acids certainly contributed to this effect by reducing platelet aggregability.