TLDR: Nothing burger junk science paper we see pumped out every 3 months from the same observational food frequency questionnaires.

Findings In this cohort study of 221 054 adults from 3 large cohorts, higher butter intake was associated with increased total and cancer mortality, while higher intake of plant-based oils was associated with lower total, cancer, and cardiovascular disease mortality.

Meaning Substituting butter with plant-based oils, particularly olive, soybean, and canola oils, may confer substantial benefits for preventing premature deaths.

Conclusions and Relevance In this cohort study, higher intake of butter was associated with increased mortality, while higher plant-based oils intake was associated with lower mortality. Substituting butter with plant-based oils may confer substantial benefits for preventing premature deaths.

Full paper: https://doi.org/10.1001/jamainternmed.2025.0205