New study reveals mixed effects of long-term fasting on health

In response to this knowledge gap, a group of researchers conducted a detailed analysis of the changes occurring in the body at a systemic level during prolonged periods of fasting. Their study, published in Nature Metabolism, revealed both beneficial and adverse effects of this phenomenon on health.

Twelve healthy volunteers were invited to participate in the experiment, undertaking a seven-day fast. During this period, they could only consume water, without any food. The participants were under constant supervision, and their health status was monitored through daily measurements of about 3000 different blood proteins.

The scientists discovered that in the first few days of fasting, the participants' bodies began to burn stored fat instead of glucose. This led to an average weight loss of about 12.6 pounds over the week, and the lost weight did not return after they resumed their normal diets.

Interestingly, significant changes in blood protein levels were not observed in the initial days of fasting. However, by the third day, the researchers noted dramatic fluctuations in hundreds of compounds that significantly affect health.

Comparing their results with other genetic studies, the authors assessed the health effects of 212 chemical compounds that changed during fasting. For instance, they noted a decreased level of the SWAP70 protein, potentially reducing the risk of developing rheumatoid arthritis. Additionally, a drop in the HYOU1 protein level may suggest a beneficial effect of fasting on heart health. However, the research also unveiled negative effects, such as an increase in coagulation factor XI, which could heighten the risk of thrombosis.

Claudia Langenberg, the lead author of the study, emphasized the significance of these discoveries for understanding the molecular mechanisms at play during fasting, pointing out health benefits beyond mere weight loss. Maik Pietzner, co-author, however, cautioned that despite potential benefits, fasting is not always a suitable option for people with health issues.