Mark R. Etherton, MD, PhD
Saber H, Yakoob MY, Shi P, Longstreth Jr. WT, Lemaitre RN, Siscovick D, et al. Omega-3 Fatty Acids and Incident Ischemic Stroke and Its Atherothrombotic and Cardioembolic Subtypes in 3 US Cohorts. Stroke. 2017
In this entry, I discuss a recent publication by Hamidreza Saber and colleagues regarding the relationship of circulating omega-3 fatty acids levels and incident ischemic stroke.
The authors set out to clarify the impact of omega-3 fatty acids on ischemic stroke incidence. Observational studies of self-reported omega-3 fatty acid consumption and omega-3 fatty acid supplementation trials have previously produced disparate results. As such, the authors quantified circulating omega-3 fatty acid levels in association with ischemic stroke incidence from 3 separate prospective cohort studies.
The authors used data from the Cardiovascular Health Study (CHS), Nurses’ Health Study (NHS), and Health Professionals Follow-Up Study (HPFS). Each of these three cohort studies represent distinct patient populations, which does influence the overall generalizability of these results. CHS is a prospective cohort study of adults aged 65 years and older. The NHS is a prospective cohort study of female registered nurses 30 to 55 years of age. Lastly, HPFS is a cohort study of U.S. male health professionals 40 to 75 years of age. Most participants in each study were white (88% in CHS, for example). The analysis of NHS and HPFS was based on a nested case-control study of age and vascular-risk factor matched controls. Ischemic stroke was subdivided into atherothrombotic, cardioembolic, or other. At the time of enrollment in the studies, blood samples were collected and stored for later analysis of omega-3 fatty acid levels. Of note, there were some differences in collection and storage of blood samples for fatty acid analysis between the three studies.