RFK Jr. warns seed oils are poisoning Americans, and a new study shows a possible link to cancer

In the ongoing war over the health of seed oils, Robert F. Kennedy may have just scored a point.

That’s because the Health and Human Services secretary has made a push for beef tallow over seed oils, by which he claims Americans are being “unknowingly poisoned”—and a new study has linked the oils, including safflower, canola, corn, soybean, and sunflower oils, to an aggressive form of breast cancer.

In the Weill Cornell Medicine study published last month in Science, researchers...