Early Protection Against Sudden Death by n-3 Polyunsaturated Fatty Acids After Myocardial Infarction, Time-Course Analysis of the Results of the Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto Miocardico (GISSI)-Prevenzione, Circulation, 2002
And saw that the benefit of taking fish oil eroded over time. The risk of death in the group taking fish oil rose over the 3.5 years of the study.
Then my eyes fell on that subgroup for nonfatal stroke, specifically 3 months in ... Does that record a relative risk (RR) of 10.51? Does that mean that people who took 1 gram of fish oil/day were ten times as likely as non-fish oil takers to have a stroke? Although the stroke risk declined over time, it remained above 1.00; the risk for stroke was always higher among fish oil takers than those in the control group who took no fish oil.
All of the participants of GISSI had recently had a heart attack - within 3 months. Taking fish oil did decrease their risk of death from a subsequent heart attack. But it also, if I'm reading this right, increased their risk for stroke - quite a lot at the beginning.