Think of snow melting and water flowing.
A recent study found that healthcare professionals undervalued the importance of proper hydration—not just for physical health, but for mental health. Water is by far our most vital nutrient, but you wouldn’t know that from how often we neglect it. Mild dehydration can occur easily; a study of the urine of schoolchildren revealed that two-thirds were dehydrated. Our brain is 75 percent water, and dehydration actually alters brain tissue, increasing fatigue and decreasing mental alertness. In a study of young healthy women, mild dehydration was induced and, according to the study results, “Significant adverse effects of dehydration were present at rest and during exercise” among the subjects. The dehydrated study participants maintained cognitive function but experienced less vigor and concentration, more fatigue, more mood disturbance, and suffered headaches. Another study, this one with male subjects, also showed cognitive function was maintained, but that mood disturbance, anger, confusion, depression, and fatigue increased. In a study of children in southern Italy, results showed that a remarkable proportion (84 percent) of children were in a state of mild dehydration at the beginning of the school day. A significant negative correlation was discovered between dehydration and memory span, which indicates that drinking supplementary water at school has a beneficial effect on short-term memory. Moreover, there was a correlation between dehydration and performance on a cognitive-challenge test.
While neurobiology is complex and the mechanisms involved with hydration status and cognition are not fully understood, these various studies reveal a consistent correlation between dehydration and memory impairment: children who are mildly dehydrated at the beginning of the school day are significantly less able to remember numbers, for example. When randomized groups of children were offered water, those children felt better and performed cognitive tasks better.
Proper hydration is critical. Without sufficient water, children and adults alike will not perform at their best. Don’t neglect this often-overlooked but vital nutrient.
Dr. Sally Fisher specializes in evidence-based integrative and nutritional medicine and is Sunrise Springs’ Medical Director.