Some recent studies on aging have demonstrated caloric restriction and fasting prolonging lifespan in animal studies, a team of researchers from Kyoto University and the Okinawa Institute of Science and Technology Graduate University examined the effects of fasting on metabolism.
Four participants were recruited for the study who were asked to fast for 58 hours, metabolomics were used to assess participant’s blood samples at different intervals during the fasting period.
Several distinct metabolic changes occur during fasting, typically the body uses carbohydrates as fuel when available but once these are depleted the body looks for other sources of energy such as amino acids. This process is called gluconeogenesis, evidence of this can be found by analyzing levels of certain metabolites within the blood such as butyrate and carnitines.
Levels of these metabolites were observed to be increased in the blood of the participants after fasting. Other metabolic changes were also observed including a significant increase in the products of the citric acid cycle. The citric acid cycle occurs in the mitochondria and its function is to release stored energy; the increase seen in the metabolites associated with this process indicate that mitochondria are overworking.
Levels of purine and pyrimidine were also found to have increased; the chemicals serve as an indicator of increased protein synthesis and gene expression, and increases suggested that fasting causes these cells to change the type and quantity of protein that they need to function.
As pyrimidine and purine are metabolized they also increase production of antioxidants, which was observed in this study with the increase in ergothioneine and carnosine. The team suggests that increase in antioxidants may be the body responding to fasting because starvation can cause high levels of oxidative stress, and by producing antioxidant it might help to prevent potential damage from free radicals.
Additionally, increases in the metabolites leucine, isoleucine, and ophthalmic acid were also observed which tend to decline with age. These increases were noted to possibly explain how fasting prolonged the lifespans in animal studies. 44 metabolites were identified to increase during fasting during this study, some increased by 60 times and 14 were previously linked to fasting.
Although gaining popularity in recent years fasting goes back centuries, and several studies have investigated the different types of fasting and their potential benefits. This type of diet may not be for everyone, but it does carry some scientifically proven health benefits including helping to regulate blood sugar, fighting inflammation, and supporting heart health. Fasting may affect people differently, and these effects can vary from person to person. As always it is recommended to consult with a trained medical professional before embarking on any diet to make sure it is best for you and avoid any possible complications.
