About the study

The justification for the Alpha Omega Trial

In 1985 Kromhout et al. showed that eating fish once or twice a week was associated with a 50% lower risk of fatal coronary heart disease in the Zutphen Study. That result was confirmed in various other cohort studies in The Netherlands and in other countries. In 1994 we observed an inverse association between fish consumption and the incidence of stroke in the Zutphen Study that was also confirmed in other cohort studies. The most likely explanation for these associations was a protective effect of the omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in fish. The Alpha Omega Trial was set up to test the hypothesis that a low dose of EPA-DHA would reduce major cardiovascular events and fatal coronary heart disease in patients who have had a heart attack.

The aim of the Alpha Omega Trial

The main aim of the Alpha Omega Trial was to examine whether major cardiovascular events and fatal coronary heart disease could be prevented by low doses of the fish fatty acids EPA and DHA in patients who have had a heart attack. In addition, the effect of the plant food-based omega-3 fatty acid alpha linolenic acid (ALA) on cardiovascular events was studied. If ALA would prevent cardiovascular events, eating plant foods rich in ALA could be a subsitute for eating fish.

Timeline of the Alpha Omega Trial

The trial started in May 2002 with a pilot study of 3 months and the inclusion of patients who have had a heart attack, was closed in December 2006. The active intervention period of 40 months was preceded by a placebo period of 6 weeks. The patients were examined at baseline and after 40 months of follow-up and at mid-term a random sample of the patients was examined for compliance purposes. Telephone calls to monitor drug treatment and the occurrence of diseases took place after 12 and 24 months of follow-up.


Prospective cohort studies have shown that omega-3 fatty acids are inversely related to cardiovascular diseases. Therefore, major cardiovascular events were selected as primary endpoint. Mortality from coronary heart disease, cardiovascular diseases and all-causes were secondary endpoints in the Alpha Omega Trial.