Replacing butter with plant-based oils good for longevity

Switching from butter to plant-based oils such as olive, soybean, or canola may help prevent premature deaths, as reported in a study.

Researchers used data from three large cohorts: the Nurses’ Health Study (1990-2023), the Nurses’ Health Study II (1991-2023), and the Health Professionals Follow-up Study (1990-2023). They identified 221,054 adults (mean age at baseline, 56.1 years for Nurses’ Health Study, 36.1 years for Nurses’ Health Study II, and 56.3 years for Health Professionals Follow-up Study) who were free of cancer, cardiovascular disease (CVD), diabetes, or neurodegenerative disease at baseline for inclusion in the analysis.

The participants completed validated semiquantitative food frequency questionnaires every 4 years, which assessed intakes of butter (butter added at the table and from cooking) and plant-based oil (safflower, soybean, corn, canola, and olive oil). These dietary data were analysed in relation to the primary outcome of total mortality and secondary outcomes of mortality due to cancer and CVD.

Over 33 years of follow-up, 50,932 deaths occurred, including 12,241 due to cancer and 11,240 due to CVD. The risk of total mortality was 15-percent increased among participants in the highest vs lowest butter intake quartile (hazard ratio [HR], 1.15, 95 percent confidence interval [CI], 1.08–1.22; p<0.001). On the other hand, the highest vs lowest intake of total plant-based oils was associated with a 16-percent reduction in total mortality risk (HR, 0.84, 95 percent CI, 0.79–0.90; p<0.001).

Specifically, every 5-g/d increment of canola, soybean, and olive oil intake conferred a mortality-risk lowering benefit (HR, 0.85, 0.94, and 0.92, respectively; p<0.001 for all). Every 10-g/d increment in plant-based oil intake reduced the risk of cancer mortality by 11 percent (HR, 0.89; p<0.001) and of CVD mortality by 6 percent (HR, 0.94; p=0.03). Finally, a higher intake of butter contributed to a 12-percent increase in cancer mortality (HR, 1.12, 95 percent CI, 1.04–1.20; p<0.001).

Substituting 10-g/d intake of total butter with an equivalent amount of total plant-based oils was associated with 17-percent lower total mortality (HR, 0.83, 95 percent CI, 0.79–0.86; p<0.001) and cancer mortality (HR, 0.83, 95 percent CI, 0.76–0.90; p<0.001).