A new study suggests that the ketogenic diet, often adopted for rapid weight loss and potential cancer treatment benefits, may paradoxically increase the risk of small intestine cancer. While the diet has shown promise in slowing the spread of colorectal cancer, researchers found it had the opposite effect in the small intestine of mice.
The ketogenic diet, which drastically cuts carbohydrate and sugar intake while emphasizing fats and protein, forces the body into a state of ketosis. This process releases ketones, such as BHB, which have been shown to slow the division of colorectal cancer cells. However, the latest research indicates that the diet's impact varies significantly across different parts of the gastrointestinal tract.
In experiments with mice, the ketogenic diet led to an increased likelihood of tumor development in the small intestine. Researchers observed that while the mice maintained a leaner physique, tumor formation rates in the small intestine were comparable to those seen in obese mice. This finding challenges the generalized view of the ketogenic diet as universally beneficial for cancer prevention.
Scientists believe the differential effects on the small and large intestines are not primarily due to ketones but are linked to the behavior of stem cells. The study found that cells burning fat during ketosis initiate a chain reaction that causes stem cells to multiply rapidly. While stem cells are crucial for self-repair in the small intestine, an overabundance of active stem cells can increase the risk of tumor formation.
Conversely, in the large intestine, ketones were considered "metabolic bystanders" with stem cell activity playing a more dominant role. This suggests that the diet's impact is tissue-specific. Researchers are calling for further investigation to understand the precise mechanisms behind these distinct reactions in neighboring organs within the GI tract.
Small intestine cancer, though rarer than colorectal cancer, has seen a significant increase in cases, doubling over the past 40 years and affecting approximately 14,400 people annually in the U.S. The study highlights the need for caution when generalizing the effects of the ketogenic diet, as what may be beneficial for one tissue could be detrimental to another.