In the ORIGIN (Outcome Reduction With an Initial Glargine Intervention) study, over 12,500 people were given a supplement of omega-3 fatty acid or a placebo for at least 6 years. All the participants had new or recently diagnosed diabetes, impaired fasting glucose, impaired glucose tolerance or other cardiovascular risk factors. Those who received the drug (though they were unaware if they were receiving drug or placebo) were given 1 gram of omega-3 fatty acid daily. Both groups had about the same baseline intake of omega-3 at the beginning and end of the study.
After 6 years, there was no difference in the rate of heart attacks in the group that received omega-3 fatty acids compared with those that did not. Added fatty acids did not have a major effect on heart attack rates or rates of death. They did not reduce strokes or heart failure either. Cholesterol levels remained the same in both groups as well.
Should you take supplemental omega-3 fatty acids? If you fall into any of the groups in this study, probably not.