This is some of the research I've found concerning dosage. Some of the studies use the higher dosages requiring closer to ten fish caps to get the required EPA/DHA amounts.
“In order to match the dosage used in several major studies, you should take enough fish oil to supply about 2-3 g of EPA (2000-3500 mg) and about 1-2.5 g of DHA daily (1000 to 2500 mg). Far higher doses have been used in some studies, however.”
http://healthlibrary.epnet.com/GetContent.aspx?token=e0498803-7f62-4563-8d47-5fe33da65dd4&chunkiid=21684“Effects of supplementation with fish oil derived n-3 fatty acids and gamma-linolenic acid on circulating plasma lipids and fatty acid profiles in women. "A randomized controlled trial on 31 women assigned some to receive either 4 g EPA/DHA (4:0 control group), 4g EPA/DHA plus 1g gamma-linolenic acid (GLA) (4:1), 2 g GLA (4:2), or 4g GLA (4:4) daily for 28 days.”
“Purified eicosapentaenoic and docosahexaenoic acids have differential effects on serum lipids and lipoproteins, LDL particle size. A study on 59 overweight, non-smoking men with mild hyperlipidemia, who consumed 4 g of EPA or DHA or olive oil for 6 weeks, reported decreased serum triglyceride concentrations in those taking EPA or DHA, both found in fish oil. In addition, the DHA-supplemented group also had a significant increase in serum HDL2 cholesterol concentrations.”
“Effect of low-to-moderate amounts of dietary fish oil in nuetrophil lipid composition and function. A study involving very high daily intake of ù-3 fatty acids (9.4 g EPA plus 5 g DHA per day) did show improvements in people with inflammatory disorders. Healthy adult male volunteers were randomized to receive one of four dietary supplements with different concentrations of fish oil or placebo oil for 12 weeks. Those receiving low to moderate concentrations of fish oil supplementation, using a daily intake of 0.58 g of EPA and 1.67 g of DHA, demonstrated modest improvements in indicators of immunity and possible reductions in inflammation.”
“Effects of oils rich in eicosapentaenoic and docosahexaenoic acids on immune cell composition and function in healthy humans. A double-blind, placebo-controlled parallel study on 42 healthy subjects was conducted to determine on the effects of EPA-rich oil (4.7 g/day) or DHA-rich oil (4.9 g/day) versus placebo (olive oil) on various immune outcomes over a 4 week period. Out of the parameters of immune function measured in the study, DHA supplementation only decreased T lymphocyte activation (assessed by expression of CD69) in healthy subjects, however EPA did not have a significant effect.”
Protective effect of Fish Oil Supplementation on Exercise-Induced Bronchoconstriction in Asthma Fish oil may be beneficial for asthmatic subjects with exercise-induced bronchoconstriction (EIB). A randomized, double-blind cross-over study was conducted on sixteen asthmatic patients with EIB following a normal diet, and either received daily fish oil supplements (3.2 g EPA, 2.0 g DHA) or placebo for 3 weeks. Pulmonary function and production of pro-inflammatory markers (i.e. leukotriene E4, prostaglandin D2, interleukin-1B, tumor necrosis factor-alpha, etc.) was assessed. The fish oil diet improved pulmonary function and significantly reduced proinflammatory eicosanoid metabolites, prostaglandins, and cytokines both before and after exercise compared to the normal and placebo diets.
http://www.vitaminherbuniversity.com/topic.asp?categoryid=3&topicid=1036