O'Reilly ÉJ, Bjornevik K, Furtado JD, et al. - Researchers intended to determine if there is a connection between prediagnostic plasma polyunsaturated fatty acids levels (PUFA) and amyotrophic lateral sclerosis (ALS). They identified 275 people who developed ALS while registered in 5 US prospective cohorts, and randomly chose 2 controls, alive at the time of the case diagnosis, matched on cohort, birth year, sex, ethnicity, fasting status, and time of blood draw. No association was found between total, n-3, and n-6 PUFA, eicosapentaenoic acid, or docosapentaenoic acid levels and ALS. The majority of individual PUFAs did not relate to ALS. In men, ALA was inversely and docosahexaenoic acid was positively associated with ALS risk, whereas arachidonic acid was positively related in women. In future studies, these findings warrant confirmation.