According to the International Food Information Council, roughly 12 percent of Americans practice some form of intermittent fasting. This hugely popular diet movement cycles between long fasting periods followed by eating periods. The goal is weight loss. But, while weight management might be an outcome of intermittent fasting, researchers have found a not-so-nice side effect: hair loss.
A new study published in Cell found an association between stunted hair regeneration and intermittent fasting in mice populations. Led by stem cell biologist Bing Zhang from Westlake University in China, researchers found that these intermittent fasting schedules had an impact on hair regrowth.
According to the study, mice who stuck to the intermittent fasting schedule only had partial hair regrowth after 90 days. The control group had almost total regrowth by 30 days.
The difference is striking. Researchers posit that fasting may impact oxidative stress and prompt hormonal changes that affect hair stem cells.
“During fasting, adipose tissue starts to release free fatty acids, and these fatty acids enter the HFSCs that were recently activated, but these stem cells don’t have the right machinery to use them,” Zhang explains in a media release.
Mice have much higher metabolisms than we do, so it’s likely that the impact on humans is not as severe.
In a small clinical trial on humans, the more extreme 18-hour fasting schedule inhibited hair growth by 18 percent. Zhang notes that these results are not representative.
“We don’t want to scare people away from practicing intermittent fasting because it is associated with a lot of beneficial effects—it’s just important to be aware that it might have some unintended effects,” Zhang emphasizes.
