Fasting, or restricting your intake of solid foods, has long been promoted as a means of losing weight. In recent years, intermittent fasting, which involves alternating restricted food intake with normal eating patterns, has gained popularity due to potential health benefits. Research has indicated that intermittent fasting may lead to weight loss, lower risk of type 2 diabetes, improved heart and brain health, reduced risk of cancer, decreased oxidative stress and inflammation, and enhanced longevity. While intermittent fasting has shown benefits for weight loss and type 2 diabetes in humans, further research is needed to confirm these effects.
A recent study conducted in mice by researchers from MIT has shed new light on how fasting and then refeeding can stimulate cell regeneration in the intestines. The study found that fasting for 24 hours followed by refeeding enhanced the ability of intestinal stem cells to multiply rapidly. This rapid regeneration of cells may promote intestinal regeneration and aid in recovery from injuries or inflammation. However, the study also revealed that this rapid regenerative state may increase the risk of developing intestinal tumors.
The researchers observed that when mTOR, a cellular signaling pathway involved in cell metabolism and growth, is activated in these stem cells during refeeding, they produce higher levels of polyamines, which are essential for cell growth and division. While this rapid regeneration of cells can be beneficial for tissue renewal, there are potential downsides to constant swings from periods of restricted food intake to normal eating patterns. The researchers found that cells in this highly regenerative state were more likely to become cancerous.
The study also demonstrated that when a cancer-causing gene was turned on in the mice during refeeding, the cells were more likely to develop into precancerous polyps compared to when the gene was activated during fasting. The researchers cautioned that exposure to mutagenic foods after fasting could increase the risk of developing cancerous lesions. They emphasized the importance of conducting careful studies to understand the effects of dietary interventions on the human body, particularly in relation to intermittent fasting.
While intermittent fasting has been associated with metabolic health benefits and tissue regeneration in various species, including humans, there is a need for further research to explore how different fasting schedules and meal contents may impact cancer risk. Registered dietitian nutritionist Kelsey Costa advised caution when incorporating fasting and refeeding cycles into diet planning to promote regeneration without increasing the risk of cancer. Overall, the study highlights the complex interplay between fasting, cell regeneration, and cancer risk, underscoring the importance of a cautious approach to dietary interventions.
