Prolonged Water-only Fasting is a Safe and Feasible Treatment Option for Managing Stage 1 and 2 Hypertension

Prolonged water-only fasting appears to reduce high blood pressure but randomized controlled trials are needed. This single arm pre-post interventional trial ( clinicaltrials.gov , NCT04515095 ) investigates the safety, feasibility, and effectiveness of prolonged water-only fasting in the treatment of stage 1 and 2 hypertension. Twenty-nine participants with stage 1 and 2 hypertension, who were pre-approved to water-only fast for ≥7 days, were enrolled from a residential fasting center. Participants received 24-hour medical supervision, and adverse events were recorded according to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Feasibility was assessed based on retention rate, ability to complete minimal fast length, and intervention acceptability. Demographic, anthropometric, medication use, laboratory, and survey data were also collected. Twenty-seven of the 29 enrolled participants attended all study visits through the six-week follow-up visit and completed at least seven consecutive days of water-only fasting. The majority of adverse events were mild and transient and there were no higher-grade or serious adverse events. Overall, the intervention was acceptable. At the six-week follow-up visit, there were sustained reductions in median systolic/diastolic blood pressure (−19.19/-5.13 mmHg), body weight (−6.72 kg), abdominal circumference, −6.55 cm), and anti-hypertensive medication use (−93%), which also persisted at the 12-month follow-up visit. These preliminary data suggest that prolonged water-only fasting is a safe and feasible treatment option for stage 1 and 2 hypertension. The data also suggest that fasting may result in sustainable reductions in high blood pressure and anti-hypertensive medication use.