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

BackgroundFasting 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. MethodsA 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. This study was registered in ClinicalTrials.gov (NCT03193177). FindingsOur 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). InterpretationThe 21-day fasting appeared safe and feasible for both healthy and unhealthy people. It could ameliorate the risk factors associated with hypertension and hyperlipidemia. FundingThis work was supported by National Natural Science Foundation of China and China Overseas-Educated Scholars Development Foundation. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSFasting has long been a ritual or practice in varied religions. In modern science, it has been noticed that fasting or calorie-restricted diets could benefit for the prevention or treatment of metabolic disorder-associated diseases. In China, the fasting practice, called "Bigu" (literally: avoiding grains), is believed to be capable of prolonging life in Taoism and was also used for medical cure. Compared to the reported fasting practices, the Bigu regimen is a more restricted abstinence, in which the practicers usually experience a continuous 21-day practice with an extremely low-calorie intake (<5% of normal diet). In a rough estimation, there are dozens of Bigu practice camps and over ten thousand practicers per year in China. However, nearly all Bigu camps followed the traditional Taoist procedures but lacked medical and scientific evaluation, which made those practices either mysterious or superstitious to the public. Added value of this studyOur data showed that no severe adverse event was reported during the 21-day fasting procedure, 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 data also presented significant ameliorations on overweight, hypertension and fatty liver. This 21-day fasting appeared safe and feasible for both healthy and unhealthy people. It could ameliorate the risk factors associated with hypertension and hyperlipidemia. Implications of all the available evidenceThis preliminary cohort study showed that the long-term extreme fasting was safety to most people and exhibited promising therapeutic effects to hypertension, hyperlipidemia and fatty liver. However, a large cohort study of health-improving effects by long-term extreme fasting is needed.