Metabolic Reactions Activated During 58-hour Fasting

By Ellie Teng ‘21

Figure 1. Fasting for at least 34 hours boosts metabolism in healthy adults.

Fasting is an ancient component in numerous religions and cultures. Individuals seeking weight loss often practice fasting, making it a prominent topic in the nutrition field. A team of scientists from the Okinawa Institute of Science and Technology Graduate University and Kyoto University recently found that fasting comes with innumerable health benefits.

Blood samples from four healthy individuals who fasted for 34-58 hours were obtained and studied by the team. The level of metabolites, which is produced by the process of metabolism, was analyzed, and researchers found more than 30 previously unreported metabolites to increase significantly during fasting. A total of 44 metabolites increased between 1.50 to 60 fold in all four volunteers. The compounds purine and pyridine are responsible for gene expression, protein synthesis, transcriptional programming, and increasing antioxidant production. These results suggest that fasting may reprogram the proteins that cells build, thus reaching homeostasis. Fasting appeared to drive the metabolism of these compounds, resulting in an increase in ergothioneine and carnosine, two antioxidants that protect against free radicals. This is beneficial to fighting aging and harmful environmental factors. Scientists also observed a spike in organic acids and coenzymes during fasting, which indicated the activation of mitochondrial activity in tissues.

Additionally, the Pentose Phosphate Pathway (PPP), metabolites, and antioxidants levels were higher during fasting, but only in plasma. Significant products of the PPP include 6-phosphogluconate and glucose-6-phosphate, which are both are essential for redox maintenance and nucleic acid synthesis. This discovery provided scientists a deeper understanding of metabolism and could be used in further research involving weight loss or aging.



  1. T. Teruya, et. al., Diverse metabolic reactions activated during 58-hr fasting are revealed by non-targeted metabolomic analysis of human blood. Scientific Reports 9, 854 (2019). doi:  
  2. Image retrieved from:

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