Water Fasting Scientist: Surprising Link Between Fasting & Cancer! Totally Reset Your Gut Microbiome

Fasting, he explains, is the complete abstinence from all substances except water, under conditions of rest. This allows the body to initiate healing processes that modern medicine often neglects. The discussion revolves around how fasting mobilizes visceral fat — the harmful fat surrounding internal organs — which secretes inflammatory chemicals contributing to diseases including heart disease, diabetes, cancer, and autoimmune disorders.

How Fasting Works in the Body

Dr. Goldhamer details the biological mechanism supporting the safety and efficacy of prolonged fasting. Initially, the body relies on glucose derived from dietary carbohydrates and glycogen stores in muscles and liver. Once these glycogen stores are depleted after approximately 24 hours, the body transitions its primary fuel source from glucose to fat-derived ketone bodies, particularly beta-hydroxybutyric acid, which the brain can utilize efficiently. This evolutionary metabolic switch allows humans to fast safely for extended periods — up to around 70 days under ideal conditions.

This metabolic shift not only contributes to weight and fat loss but also enhances the production of brain-derived neurotrophic factor (BDNF), a neurochemical that protects against neurodegenerative conditions including Alzheimer's disease. Fasting's effects on BDNF mirror many of the beneficial biochemical changes observed in exercise, despite exercise and fasting feeling very different physiologically.

The Resetting of the Gut Microbiome

A particularly fascinating aspect of fasting discussed in the podcast is its profound impact on the gut microbiome. Dr. Goldhamer reveals recent research demonstrating that after a seven-day water fast, harmful bacteria such as fusobacteria decline significantly — by more than 80% — which shifts the gut microbiome to a healthier balance. This "reset" enables the gut to recover and regenerate during the carefully managed refeeding phase.

Given that the gut microbiome influences not only digestive health but also cognitive function — with approximately 90-95% of dopamine and serotonin production occurring in the gut — fasting's capacity to recalibrate this ecosystem could partly explain benefits seen in mood disorders like depression and anxiety. Moreover, the gut microbiome's role in hormone metabolism, such as estradiol breakdown, suggests why fasting may also help manage hormone-related conditions in women like fibrocystic breast disease, polycystic ovarian syndrome, and dysmenorrhea.

Clinical Applications of Water Fasting

Dr. Goldhamer's True North Health Center specializes in medically supervised water fasting programs ranging from 5 to 40 days, with the vast majority of patients fasting between 10 to 20 days. Patients eligible for these fasts undergo thorough medical evaluations to ensure safety, including assessments of kidney and liver function, electrolyte balance, and medication needs.

Among the diseases treated successfully with fasting at his clinic, hypertension stands out as the most striking. In one study involving 174 consecutive patients with high blood pressure, all were able to reduce or eliminate medication and normalize blood pressure after an average two-week water fast, with many maintaining these benefits sustainably for over a year thanks to adherence to a whole-food, plant-based, "SOS-free" diet (free from sugar, oil, and salt) post-fast. Similar success is reported with type 2 diabetes, autoimmune diseases, digestive disorders such as ulcerative colitis and Crohn's disease, and even certain cancers, notably lymphoma, as detailed in long-term case studies where patients achieved remission following fasting combined with dietary changes.

Psychological and Behavioral Effects of Fasting

Beyond physiological healing, Dr. Goldhamer emphasizes the transformative psychological dimension of water fasting. Patients frequently experience substantial shifts in willpower, motivation, and cognitive clarity during and after fasting. The practice helps reset dopamine pathways, recalibrates taste sensitivity, and strengthens mental discipline by disproving common misconceptions about hunger and survival. Once individuals successfully undergo an extended fast, their relationship with food, cravings, and satiety often changes profoundly, supporting healthier long-term habits and increased resilience against societal pressures to overeat processed, hyper-palatable foods.

Distinguishing Water Fasting from Other Fasting Modalities

The conversation contrasts water-only fasting with other forms such as juice fasting and ketogenic diets. Juice fasting, although easier and suitable for unsupervised situations, does not produce the same detoxifying and regenerative effects as water fasting due to its sugar content and lack of fiber, which sustains the feeding state and limits autophagy and deep metabolic recovery.

Ketogenic diets mimic some aspects of fasting through metabolic ketosis and can stabilize cognitive function by smoothing out blood sugar fluctuations, but Dr. Goldhamer highlights risks associated with high-protein and high-fat approaches — especially those rich in animal products — that may contribute to kidney disease, cardiovascular problems, and cancer risk. He advocates for whole-food, plant-based diets as optimal for obtaining nutrients without the downsides of dietary excess and processed foods.

Safety, Refeeding, and Medical Supervision

Safety in prolonged fasting is paramount. Dr. Goldhamer stresses the necessity for patients to rest during fasting to minimize lean tissue breakdown that occurs with physical exertion and to ensure careful monitoring of hydration, electrolyte levels, and blood pressure. He describes the importance of controlled refeeding, starting with fruit and vegetable juices progressing gradually to whole foods over a period roughly half the length of the fast, to prevent dangerous complications such as refeeding syndrome.

He also dispels myths about fasting-induced muscle loss and nutrient depletion, citing the body's remarkable capacity to recycle nutrients during fasting when done correctly and under medical supervision.

Fasting for Healthy Individuals and Preventive Care

Even individuals considered healthy stand to benefit from periodic fasting. Dr. Goldhamer recommends a daily minimum fasting period of around 12 hours and often suggests a once-a-year one-week water fast to reboot metabolic and cognitive functions, reset the gut microbiome, and recalibrate taste preferences. Most people, he notes, are unknowingly metabolically unhealthy due to excess visceral fat and inflammation despite the absence of overt symptoms.

Finally: The Bigger Picture of Health and Lifestyle

Dr. Goldhamer frames fasting as a powerful tool embedded within a broader context of healthful living. He stresses that the root of chronic diseases lies not in pills or supplements but in lifestyle factors — diet, sleep, exercise, and avoidance of processed foods laden with salt, oil, and sugar. Fasting provides a biological "reset" that enables the body to heal itself when given rest and the right environment.

The challenge remains adherence to sustainable lifestyle choices after fasting. True and lasting improvements require ongoing commitment to a nutrient-dense, plant-based diet paired with healthy behaviors.

Conclusion

Dr. Goldhamer's extensive clinical experience combined with detailed scientific explanations demystify water fasting as both a safe and potent therapeutic intervention. Beyond rapid reductions in visceral fat and normalization of blood pressure and blood sugar, fasting acts as a "hard reboot" for the gut microbiome, immune system, hormonal balance, and brain biochemistry. It reshapes one's psychological relationship to food and health, empowering individuals to reclaim vitality and resist the friction of a modern environment designed to promote dietary excess.

While not a panacea nor a replacement for all conventional care, Dr. Goldhamer presents water fasting as a uniquely effective option for people grappling with chronic disease — and a compelling preventive strategy for healthy individuals seeking to optimize wellness, longevity, and quality of life. The key takeaway is that fasting, properly supervised and integrated into a whole-food plant-based lifestyle, can fundamentally shift health trajectories in ways that few other interventions have demonstrated.