Fasting is most often used for weight loss, though the conventional view among medical professionals is that fasting — simply declining to eat for limited periods of time, sometime for days at a time — has not been shown to be a healthy way to lose weight, according to the medical site WebMD. But a new study by researchers in Japan suggests that fasting may, indeed, have a number of previously unknown health benefits and may even offer a way to reverse the aging process.
The study published late last month in the journal Scientific Reports was conducted by scientists in Japan at Okinawa Institute of Science and Technology Graduate University, as well as Kyoto University. Their findings showed that 30 previously-unreported metabolic substances see increased production in the human body during fasting, and those substances help govern human metabolism. In the higher quantities resulting from fasting, the substances would actually speed up the metabolic process.
Earlier research has found that three metabolites, in particular — leucine, isoleucine, and ophthalmic acid — tend to decrease in the body as humans age. But the new study found that those substances actually increased the body during periods of fasting, according to a summary of the study in Science Daily, which noted that the results “suggest a mechanism by which fasting could help increase longevity.”
Some of the metabolic compounds peaked in production after 34 hours of fasting, the study showed according to a summary by Inverse.com. But levels of other substances continued to rise up to 58 hours, which was the full amount of time subjects the study engaged in fasting. The substances reached levels up to 60 times their normal levels.
“These are very important metabolites for maintenance of muscle and antioxidant activity, respectively,” said lead researcher Dr. Takayuki Teruya of the Okinawa Institute.
“This result suggests the possibility of a rejuvenating effect by fasting, which was not known until now.”
In addition to the possible positive effects on longevity, fasting led to an increase in the production of antioxidants, which can reduce or in some cases reverse the effects of aging. But the scientists cautioned that the full effects of prolonged fasting on the body remain unclear, because the study did not monitor the long-term health of the subjects, or follow them over multiple fasting periods.
“We have been researching aging and metabolism for many years and decided to search for unknown health effects in human fasting,” Teruya, quoted on the Okinawa Institute site.
“Contrary to the original expectation, it turned out that fasting induced metabolic activation rather actively.”