From the abstract: "Twelve healthy male volunteers (aged 53–65 yr) were assigned to consume an intake of successively 200, 400, 800, and 1600 mg/d DHA, as the only {omega}-3 fatty acid, for 2 wk each dose."
I don't know what inconsistency you noticed between the news article and the abstract, but it seems the abstract itself describes a study that is missing the control group that gets a dosage of 0.
The following sounds like a control measurement was taken:
"Blood and urine samples were collected before and after each dose of DHA and at 8 wk after arrest of supplementation."
Also note, that the abstract doesn't say that 200mg is ideal as the science daily description does it says:
"It is concluded that low consumption of DHA could be an effective and nonpharmacological way to protect healthy men from platelet-related cardiovascular events."
I declare this Open Thread open for discussion of Less Wrong topics that have not appeared in recent posts.