Intermittent fasting has been widely studied for its potential benefits, including weight loss and reduced risk of dementia. However, a new research study in mice has uncovered a potential downside to periodic food abstinence: an increased risk of cancer.
The research found that fasting in mice led to a boost in the regenerative capabilities of their intestinal stem cells, which can protect against injury and inflammation. However, upon refeeding, the increase in stem cell production accelerates. This heightened activity, combined with exposure to mutagens found in certain foods, such as heterocyclic amines in burned meats, can elevate the risk of developing cancerous tumors.
The study identified a biological pathway called mTOR, which plays a crucial role in cell growth and metabolism. After fasting, this pathway increases the production of polyamines, small molecules that drive cell proliferation. While polyamines are essential for recovery and regeneration after fasting, they can also contribute to the formation of tumors, especially in conditions conducive to cancer growth.
Researchers point out that fasting and refeeding represent two distinct states for cells. During fasting, cells utilize lipids and fatty acids as an energy source to survive when nutrients are scarce. It is during the post-fast refeeding state that cell regeneration is significantly enhanced. This dichotomy underscores the complexity of the cellular response to intermittent fasting and its potential implications for cancer risk.
While previous studies have suggested that fasting and fasting-mimicking diets could reduce the risk of cancer and enhance the effectiveness of anti-cancer therapies, the findings of this study highlight the importance of considering the potential consequences of breaking the fast. Further research is needed to better understand how to leverage the benefits of fasting while mitigating the associated risks.
It is important to note that the study was conducted in mice with specific cancer mutations, and the results may not directly translate to humans. Additional studies are necessary to elucidate the effects of intermittent fasting on cancer risk in humans. The complexity of the relationship between fasting, stem cell activity, and cancer underscores the need for further investigation to refine our understanding of these interconnections.
While intermittent fasting has been lauded for its potential health benefits, including weight loss and improved metabolic health, the findings of this study shed light on a potential drawback: an increased risk of cancer due to heightened stem cell activity and exposure to mutagens during refeeding. Understanding the underlying mechanisms driving this risk is crucial for developing strategies to maximize the benefits of intermittent fasting while minimizing the potential harm.