UNVERIFIED

Scientific research currently lacks clinical evidence to support the claim that a single 7-day fast reduces an individual's lifelong cancer risk by 70%. High-credibility sources state that there is little human evidence to substantiate specific claims regarding fasting and cancer prevention 4. While studies in mice and monkeys have shown up to a 50% reduction in spontaneous cancer incidence, these results were based on chronic daily calorie restriction maintained over a lifetime rather than a one-time fasting event 5. Fasting and Fasting Mimicking Diets (FMD) have demonstrated the ability to reduce metabolic risk factors such as insulin levels, inflammation, and oxidative stress, but human data regarding long-term cancer prevention remains limited 3, 7, 9. While some experts suggest fasting can target inflammation that contributes to tumor growth in animal models, larger-scale human trials are necessary to confirm any significant reduction in disease risk for people 8, 9. For a detailed review of human metabolic adaptations and limited clinical data, refer to the research published in CA: A Cancer Journal for Clinicians 3 and the UCSF Osher Center 5.