The health benefits of alkaline water: is it a fact or marketing myth?

BACKGROUND: Alkaline water has gained widespread popularity and is frequently marketed for benefits related to hydration, acid-base balance, metabolic health, and immune function. These claims are increasingly encountered in primary care, yet their clinical validity remains uncertain. OBJECTIVE: To critically evaluate current evidence on alkaline water, focusing on its physiological effects, clinical relevance, and safety in routine patient care. METHODS: A narrative review of the literature was conducted, including human clinical studies, experimental interventions, and animal models. Outcomes examined included gastrointestinal health, hydration status, bone metabolism, metabolic parameters, oxidative stress, and immune function. RESULTS: Evidence suggests that alkaline water provides limited, context-specific benefits. The most consistent findings relate to gastrointestinal effects, particularly pepsin inactivation and potential improvement in reflux-related symptoms. Modest effects on hydration markers, urinary pH, and selected indicators of bone resorption have been reported, especially with bicarbonate-rich formulations. In contrast, evidence supporting metabolic, antioxidant, and immunological benefits is inconsistent and largely derived from small or preclinical studies. Claims of systemic alkalinization, enhanced immunity, anti-aging, and disease prevention are not supported by robust clinical evidence. CLINICAL IMPLICATIONS: Alkaline water should not be routinely recommended in primary care. Clinicians should emphasize evidence-based interventions and exercise caution in vulnerable populations, including individuals with chronic kidney disease, those on acid-suppressive therapy, pregnant women, and children. CONCLUSION: Alkaline water has limited clinical utility. Its effects are modest and likely driven more by mineral composition than pH alone. Further well-designed, long-term studies are required before definitive recommendations can be made.