Guasch-Ferre M, et al. - In this study involving 63,412 women from the Nurses' Health Study (1990-2012) and 29,966 men from the Health Professionals Follow-Up Study (1990-2012), researchers examined the associations of cis-monounsaturated fatty acid (MUFA) intake from plant (MUFA-P) and animal (MUFA-A) sources with total and cause-specific mortality. Using data collected via validated food frequency questionnaires administered every 4 years and updated food composition databases, the investigators estimated MUFA-Ps and MUFA-As. Participants were assessed during 1,896,864 person-years of follow-up, during which time 20,672 deaths were documented. Findings revealed lower total mortality in association with higher intake of MUFA-Ps. They also found higher mortality in association with MUFA-As intake. Replacement of saturated fatty acids (SFAs), refined carbohydrates, or trans fats by MUFA-Ps, but not MUFA-As, resulted in significantly lower mortality risk. The authors also noted evidence suggestive of possible confounding of the associations for MUFAs by other constituents in animal foods, such as SFAs; this could be the case when they are primarily derived from animal products.