(NewsNation) — Intermittent fasting has been shown to have several health benefits, but new research shows it also may increase the risk of colon cancer.
In the study conducted on mice, Massachusetts Institute of Technology researchers looked at three groups: one that fasted for 24 hours and did not eat, another that fasted for 24 hours and ate whatever it wanted during a 24-hour “refeeding” period, and a third that ate whatever it wanted throughout the experiment.
Researchers analyzed the mice’s intestinal stem cells at different points and found that the ability of these cells to multiply was highest during the 24-hour refeeding period in the mice that had previously fasted. These stem cells also replicated more rapidly than those in mice that did not fast, which could pose a problem if the cells mutate into precancerous ones.
Researchers then activated cancer-causing genes in the mice, making them more prone to developing tumors. They discovered that mice who fasted and then ate during the refeeding period had a higher risk of developing precancerous polyps in their intestines and guts compared to mice who ate normally or only fasted.
Dr. Omer Yilmaz, the study’s lead author, emphasized that the findings were observed in mice and cautioned against directly comparing them to humans.
“In humans it’s going to be a much more complex state. But it does lead us to the following notion: Fasting is very healthy, but if you’re unlucky and you’re refeeding after a fasting, and you get exposed to a mutagen, like a charred steak or something, you might actually be increasing your chances of developing a lesion that can go on to give rise to cancer,” Yilmaz said, as reported by MIT News.
Intermittent fasting involves cycling between periods of fasting and eating, with variations such as eating every other day, fasting two days a week or limiting eating to specific hours each day. Time-restricted eating, where all daily meals are condensed into a window of 10-12 hours or less, is the most popular form.
Health benefits of intermittent fasting may include weight loss, improved heart and brain health and reduced oxidative stress and inflammation.