A new MIT study published in Nature reveals that a ketogenic diet has opposite effects on cancer risk depending on where you look in the gut. In cancer-prone mice, keto increased tumor formation in the small intestine while reducing colon tumors — mirroring earlier findings. The culprit was not ketone bodies themselves, but how intestinal stem cells processed the diet's high fat load. Fat metabolism pushed these stem cells to divide faster, raising the odds of cancerous mutations. The study underscores that blanket claims about keto and cancer protection are oversimplified, and that tissue-specific responses can be dramatically different even within neighboring parts of the same organ.
