Previous research has linked intermittent fasting to benefits such as weight loss and a reduced risk of developing dementia. However, a new study by an international team of scientists led by researchers from the Massachusetts Institute of Technology (MIT) has revealed that this type of fasting may actually increase the risk of cancer.
This discovery builds on the team’s earlier work, which found that fasting in mice enhanced the regenerative abilities of their intestinal stem cells while also protecting them from injury and inflammation. Now, the researchers have reached a rather alarming conclusion.
What Did the Scientists Discover?
The team found that the production of stem cells in mice accelerates when the rodents resume normal eating after intermittent fasting. During this time, food can introduce mutagens into the body—compounds such as heterocyclic amines found in charred meat products. These compounds can cause genetic mutations that increase the risk of tumor formation.
“High stem cell activity is beneficial for regeneration, but an excess of this beneficial factor over time may have less favorable consequences,” said Omer Yilmaz, a biologist at MIT and the lead author of the study.
According to him, “Fasting is very beneficial, but if you’re unlucky enough to be recovering from it and then exposed to a mutagen, like a charred steak, there’s a chance of developing cancer.”
Intestinal stem cells are among the busiest in the body. They constantly divide and grow to rebuild the intestine every 5 to 10 days. This high level of activity also means that aberrations leading to cancer are more likely to occur. This likelihood increases even further during the heightened period after fasting, as reported by Science Alert.
The team identified a biological pathway known as mTOR, through which stem cells operate. This pathway is involved in cell growth and metabolism, and after fasting, it increases the production of small molecules called polyamines, which stimulate cell proliferation.
These molecules play a crucial role in recovery and regeneration after the body has been deprived of nutrients and energy during fasting. However, the study also showed that the likelihood of developing tumors increases.
What Are the Conclusions?
Previous studies have shown that fasting and diets can be beneficial in reducing the risk of cancer and even enhancing the effectiveness of cancer therapies. However, those studies primarily focused on the act of abstaining from food and overlooked its potential consequences.
The team is preparing for further research to identify ways to enhance the effectiveness of intermittent fasting while simultaneously mitigating risks.
As is often the case in such studies, animal models can provide only a limited amount of information. Therefore, the next phase of research is planned to be conducted on humans.
The findings of the study were published in the journal Nature.