Effects of Natural Reduced Water on Cognitive Function, Body Composition, and Psychological Function in Older Adults: Study Protocol for a Randomized Controlled Trial

Natural reduced water is natural water that contains active hydrogen and reduces oxidation. It is rare in the world, and in Japan, it is produced in the Hita area of Oita Prefecture (Hita Tenryosui water). Previous studies in humans have examined the effects of natural reduced water on diabetes, which is one of the known risks for dementia. Animal studies of natural reduced water have revealed anti-obesity and anti-anxiety effects. However, the effects of natural reduced water on cognitive function, body composition, and psychological function in humans are unknown. Therefore, we investigated the relationship between these items in elderly people who continuously consume natural reduced water. In this study, we recruited participants aged between 65 and 74 years. The participants were randomly and blindly assigned to a natural reduced water (Hita Tenryosui water) group or a control (tap water) group and drank 1 L of water daily for 6 months. Cognitive function, body composition, and psychological function were measured before and after the 6-month intervention period.