Dr. Alan Goldhamer: How water fasting fights hypertension

Goldhamer cites a study of 174 consecutive hypertensive patients, all of whom achieved normal blood pressure without medication after supervised water-only fasting and refeeding. A prospective study with Mayo Clinic collaborators showed similar results, with most participants maintaining lower blood pressure and weight one year later if they adopted a whole-food, plant-based diet. He argues that medications treat the diet-induced cause, not the underlying lifestyle, and that fasting rapidly removes the visceral fat and sodium burden driving hypertension.

During a typical two-week fast, patients in Goldhamer’s data lost about 10% of total body weight, 20% of total fat, and roughly 40% of visceral fat, while lean tissue loss averaged only ~6% and was fully recovered within six weeks. Visceral fat, which surrounds organs and accumulates around the belly, secretes inflammatory molecules linked to heart disease, cancer, diabetes, and autoimmune illness. By rapidly mobilizing visceral fat, fasting can accelerate improvement in conditions like hypertension, type 2 diabetes, and autoimmune diseases compared with diet and exercise alone.

After roughly 16–48 hours of not eating, glycogen stores deplete and the brain shifts from using glucose to ketones, especially beta-hydroxybutyrate, as its primary fuel. Elevated ketones correlate with increased BDNF (brain-derived neurotrophic factor), which in animal models protects against oxidative damage and Alzheimer’s-like changes. Goldhamer suggests that people who feel mentally sharper in ketosis may benefit less from ketones per se and more from escaping blood sugar and insulin ‘rollercoasters’ associated with refined carbohydrate intake.

Goldhamer describes large drops in total microbial load during fasting followed by repopulation during refeeding, with composition depending on the post-fast diet. He links this reset to improvements in ulcerative colitis, Crohn’s disease, IBS, chronic constipation, and even depression and anxiety, noting that most serotonin and dopamine are produced in the gut. He also reports clinical improvements in PCOS, dysmenorrhea, menorrhagia, fibrocystic breast disease, and fatty liver disease, hypothesizing that fasting and microbiome shifts normalize estradiol metabolism via better liver and gut function.

Fasting increases sensitivity to salt and sugar, making whole plant foods taste better and processed foods less appealing, which Goldhamer calls ‘taste neuroadaptation.’ By experiencing days or weeks with no food, patients lose fear of hunger and gain confidence that skipped meals or delayed eating are safe, undermining ‘learned helplessness’ around chronic disease and weight loss. He argues that this psychological reset—combined with education during retreats—helps patients sustain difficult lifestyle changes after the fast.