Water supplementation after dehydration improves judgment and decision-making performance

Previous research has shown that dehydration and water supplementation affect mood and cognitive performance in both adults and children on a variety of tasks that assess memory, attention, executive function, and speeded responses. Given the varied effects of water on cognition, this study explored potential effects of water supplementation, hydration status, and thirst on thinking and decision-making tasks. Twenty-nine adult participants undertook a battery of cognitive tests on two separate occasions after having fasted from the previous night. On one occasion, they were offered 500ml of water to drink prior to testing. Measures of urine osmolality confirmed the group-level effectiveness of the dehydration manipulation. Water supplementation was found to improve performance on tasks measuring cognitive reflection in judgement and decision-making. This increase in performance was associated with differences in tasks implicated in inhibition processes. Drinking water after a 12-hour dehydration period increased performance in judgement and decision-making tasks, and this was not explained by differences in subjective thirst or attentiveness

Cytokines and water distribution in anorexia nervosa

In patients with anorexia nervosa (AN), decreased intracellular (ICW), extracellular (ECW), and total body water (TBW) as well as changes in serum cytokine concentrations have been reported. In this exploratory study, we measured body composition and serum cytokine levels in patients with AN (n=27) and healthy controls (HCs; n=13). Eating disorder symptom severity was assessed using the Eating Disorder Examination-Questionnaire (EDE-Q). Body composition was determined by bioimpedance analysis (BIA) which provided information on ICW, ECW, and TBW. Following blood collection, 27 cytokines and chemokines were quantified using multiplex ELISA-based technology: Eotaxin, Eotaxin-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon- (IFN-) γ, interleukin- (IL-) 1α, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12/IL-23p40, IL-12p70, IL-13, IL-15, IL-16, IL-17A, interferon γ-induced protein- (IP-) 10, macrophage inflammatory protein- (MIP-) 1α, MIP-1β, monocyte chemoattractant protein- (MCP-) 1, MCP-4, thymus and activation-regulated chemokine (TARC), TNF-α, and TNF-β. ICW, ECW, and TBW volumes were significantly lower in patients with AN than in HCs. In the whole sample, GM-CSF, MCP-4, and IL-4 were positively, whereas IFN-γ, IL-6, and IL-10 were negatively associated with all three parameters of body water. In AN participants, we found a statistically significant negative correlation of IL-10 with ICW, ECW, and TBW. Our results suggest an interaction between body water and the cytokine system. Underlying mechanisms are unclear but may involve a loss of water from the gut, kidneys, or skin due to AN-associated inflammatory processes