A Preliminary Retrospective and Prospective Cohort Study on a Traditional Chinese Long-Term Extreme Fasting

Background: Fasting has long been a ritual or practice in varied religions, and recently, has been noticed to reduce the risk factors of metabolic diseases. In China, varied populations performed a traditional Taoism fasting practice, which lasted for 21-day with <5% calorie intake. However, the safety and applicability of this procedure haven not been investigated. Methods: A total of 144 volunteered participants in six camps following the 21-day fasting (with <5% of normal diet) were investigated. 124 were examined for physical biomarkers and 53 of which also had biochemical markers. Another open label, non-comparative, phase 1/2 prospective cohort study enrolling 20 participants with metabolic diseases was also performed. The physical indices and biochemical biomarkers were collected at varied point of the fasting procedure. Statistical comparison and metagenomic analysis were performed. Findings: Our preliminary retrospective cohort study showed that no severe adverse event (grade 3 or above) was reported, and all biomarkers fluctuated within the safe ranges, except for the urea acid. The 21-day fasting could significantly reduce BMI and blood pressures. The prospective cohort study of the metabolic diseased participants showed a significant reduction of BMI (3.3±1.0) and systolic blood pressure (28.7±17.8 mmHg) after the fasting procedure. The data also presented significant ameliorations on overweight (16/16), hypertension (11/11) and fatty liver (9/9). Interpretation: The 21-day fasting appeared safe and feasible for both healthy and unhealthy people. It could ameliorate the risk factors associated with hypertension and hyperlipidemia. Trial Registration: This study was registered in ClinicalTrials.gov (NCT03193177). Funding Statement: The study was supported by National Natural Science Foundation of China (numbers 81571532, 81771687 and 81601429). MZ was supported by the China Overseas-Educated Scholars Development Foundation. DL was supported by the National Program for Support of Top-notch Young Professionals. Declaration of Interests: The authors declare that they have no conflicts of interest. Ethics Approval Statement: All participants have signed voluntary informed consent for collection and analysis of blood and fecal microbiome samples under Institutional Review Board (IRB)–approved protocols (THUMED-BG-170612).