MIT Study: Keto Diet May Increase Small Intestine Tumor Risk

Massachusetts Institute of Technology researchers link ketogenic diet to increased small intestine tumor risks

Researchers at the Massachusetts Institute of Technology discovered that a ketogenic diet increases small intestine tumor risks in mice genetically prone to cancer. The high-fat, low-carbohydrate eating plan accelerates cell division in the small intestine, contrasting with its previously observed ability to suppress tumors in the colon.

The finding highlights how identical dietary shifts produce opposing outcomes in adjacent digestive tract tissues. Investigators traced the increased tumor formation to how intestinal stem cells process dietary fats rather than to ketone bodies themselves.

Cellular mechanisms drive small intestine tumor growth

The ketogenic diet severely restricts carbohydrates, forcing the body to burn fat for energy and generate ketone bodies like beta-hydroxybutyrate. While a 2022 study indicated that beta-hydroxybutyrate protects against colon cancer, the MIT research published in the journal Nature demonstrated that the same metabolic shift harms the small intestine.

Fatty acid oxidation activates the PPAR protein family, which forces intestinal stem cells to divide more rapidly. Omer Yilmaz, director of the MIT Stem Cell Initiative and senior author of the study, noted that the diet creates distinct effects across different gastrointestinal tissues.

Experimental findings compare keto diets to high-calorie regimens

In laboratory experiments, genetically susceptible mice fed a ketogenic diet developed small intestine tumors more frequently than control mice. The tumor rate in the keto group matched or exceeded the rate seen in mice fed an obesity-inducing high-fat and high-calorie diet, even though the keto-fed mice did not develop obesity.

The acceleration of tumors stems entirely from how stem cells burn dietary fat. Researchers concluded that commercial ketone supplements and drinks likely will not replicate either the small intestine tumor increase or the colon tumor reduction, because those changes rely on fat metabolism rather than ketone molecules.