MedicalResearch.com: What are the main findings of the study?
Dr. Chowdhury: Total saturated fatty acid, whether measured as a dietary intake variable or in the bloodstream as a biomarker, was not associated with coronary disease risk in combining all available prospective observational studies. Similarly, there were non-significant overall associations in the prospective studies that involved assessments of total monounsaturated fatty acids, long-chain omega-3 and omega-6 polyunsaturated fatty acids.
However, we found diversity in the observational associations between specific circulating long-chain omega-3 and omega-6 fatty acids with coronary risk, with some evidence that circulating levels of eicosapentaenoic and docosahexaenoic acids (ie, the two main types of long-chain omega-3 polyunsaturated fatty acids), and arachidonic acid are each associated with lower coronary risk. Similarly, within saturated fatty acids, there were positive, however, non-significant associations observed for circulating blood composition of palmitic and stearic acids (found largely in palm oil and animal fats, respectively), whereas circulating margaric acid (a milk fat) had a significant inverse association.
Additionally, when we investigated the randomised controlled trials that reported on the effects of omega-3 and omega-6 fatty acids on reducing coronary outcomes, there was no significant overall association observed.