Why was this study done?

Consuming fish on a regular basis has a positive benefit for cardiovascular health. It is thought that the reason for this relationship is that Omega-3 fish oils improve blood lipid (cholesterol, triglyceride) levels. This study was designed to investigate the relationship of differing doses of omega-3 fish oil (1, 3, 6 grams a day) on typical cardiovascular risk factors.

What did the study find?

The 1-gram/day dose did not alter EPA status significantly following 4 weeks of supplementation. The 3-gram/day dose was sufficient to alter EPA status, but only the 6-gram/day dose was able to significantly reduced triglycerides and increased HDL.

 

Effect of Low Dose Omega-3 Fatty Acids on Plasma Fatty Acids and Lipids.
Authors: Spiller, GA, Jensen CD, Scala J,
Am J Clin Nutr, 1987. 45: p. 857.PDF Abstract: Am J Clin Nutr, 1987.