This publication presents a systematic review and meta-analysis of prospective cohort studies examining the associations between fatty acid intake and various health outcomes. The study, conducted by Russell J. de Souza and colleagues under the auspices of the World Health Organization, evaluates the impact of polyunsaturated fatty acids (PUFA) on all-cause mortality, type 2 diabetes, breast cancer, mental health, and other diseases. Utilizing the GRADE approach, the research assesses the quality of evidence and explores the effects of different types of PUFA, including omega-3 and omega-6, on health. The findings are intended for health professionals and researchers to inform dietary guidelines and public health policies.