They discovered an unexpected effect of intermittent fasting on intestinal cells.

Can doing too much of something you do well end up being harmful? That’s what researchers at Massachusetts Institute of Technology (Massachusetts Institute of Technology) O intermittent fasting.

In a study conducted on mice and published in the journal Nature, experts noted that after period of abstinence from food, stem cells in the intestines of animals they increased to compensate for the damage.

And by confirming that this regeneration only occurred after the mice resumed feeding, they emphasized that this stem cell activation had negative consequencesbecause mice that had genetic changes linked to cancer after fasting were more likely to develop early polyps in the intestines compared to those that had not fasted at all.

This phenomenon is the result of a number of complex mechanisms. Previous research from MIT has shown that fasting can enhance the positive effects by stimulating reparative abilities of intestinal stem cellsthereby promoting intestinal recovery after damage or inflammation.

In the study, the researchers wanted to understand how and when fasting leads to an increase in stem cell activity and numbers. And they did this by studying three groups of mice: animals that fasted for 24 hours, those that were allowed to “resume feeding” (eat again for 24 hours after a 24-hour fast), and those that could eat whenever they wanted during the fasting study.

According to the associate professor of biology at the Massachusetts Institute of Technology, a member of Koch Institute for Comprehensive Cancer Research and lead author of the new study, Omer Yilmaz“high stem cell activity is beneficial regenerationBut too much of something positive can have negative consequences over time“.

The researcher believes more research is needed to determine whether fasting makes a difference. similar effects in humans.

And he expanded: “We still have much to discover, but it is noteworthy that the fasting state or refeeding during mutagen exposure can significantly impact the likelihood of cancer development in these well-defined mouse models.”

Popular for some time, with celebrities and influencers saying they follow various types of intermittent fasting, this method restricts food intake for a certain number of hours.

There are several ways to practice intermittent fasting.One of the most well-known methods is time-restricted feeding, which involves regular periods of fasting and eating over a 24-hour cycle. With this approach, eating is limited to eight to ten hours or less per day.

There are fasts of 12, 14, 16 or 24 hours according to the following scheme: 16/8 most popularpartly due to its adoption by various celebrities. This plan consists of fasting for 16 hours and eating during the remaining eight hours, during which it is important to maintain a healthy and balanced diet.

For decades, scientists have explored the potential health benefits of fasting, finding evidence that the practice can delay the onset of certain diseases and extend the lives of rodents. However, the biological mechanisms that explain these benefits have been largely unknown.

In 2018, Yilmaz and his team discovered that stem cells may be involved in this process, as they saw that during starvation, these cells begin to use fats instead of carbohydrates as a source of energywhich improves its ability to repair damage in the intestines of mice.

In the present study, intestinal stem cells proliferated at an accelerated rate in mice fed after a period of fasting. These cells are critical for restoration and regeneration of the intestinal mucosapartly because they produce large amounts of molecules called polyamines, which are essential for cell growth and division.

At the same time, Yılmaz believed that “so much attention was paid to fasting and its duration that another aspect was overlooked: what happens during the fasting period.” food reintroduction?

“We believe that fasting and refeeding are two different states,” he said. Shinya Imadaanother of the study’s authors.

And he explained: “During starvation, the ability of cells to use lipids and fatty acids as an energy source allows them to survive in conditions of low nutrient availability. Instead, It is the recovery period after fasting that really promotes regeneration.When nutrients are present, these stem and progenitor cells activate mechanisms that allow them to increase cell mass and rebuild the intestinal lining.”

In addition, the researchers found that in this highly regenerative state, stem cells were more effective. tendency to cancer. Intestinal stem cells are among the fastest dividing cells in the body, completely renewing the intestinal lining every five to ten days. Because of their rapid rate of division, these cells are a common source of early cancer cells in the intestine.

During the study, scientists noticed that activate the cancer gene Mice during the refeeding phase were significantly more likely to develop early polyps compared to genes activated during fasting. Cancer-associated mutations induced during refeeding were also more likely to form polyps compared to mutations that arose in mice that did not undergo the fasting and refeeding cycle.

And while it is true that researchers should always be concerned about anything that can cause cancer, the Italian biologist and professor, director of the University of Southern California’s Longevity Institute, Valter Longosuggested that mice with the modified genes were “almost doomed to get cancer” and that the small increase in risk found in this study may not apply more generally.

In this regard, he mentioned a study he published in 2015 yearaccording to which abnormal growth of cells and tissues in mice that fasted, compared to animals that did not, it was 45% lower.

According to Longo, the results of the study Nature They may help identify ways to coordinate cell regeneration to repair damaged tissue, such as in people with inflammatory bowel disease or Crohn’s disease.

And while the new findings clearly show that the refeeding period creates a “vulnerable state” that may warrant extra caution around anything that might damage cellular DNA, Yilmaz insisted that he and his colleagues are planning a clinical trial to see if what was observed in the study happened Nature They apply to people.