Research conducted since the turn of the millennium supports that even slight dehydration impacts not only our mood but our ability to think clearly and control our mood.
In 2012, research from the University of Connecticut's Human Performance Laboratory found that even mild dehydration caused headaches, fatigue, and difficulty concentrating in the young women who participated in the study. The women showed no reduction in cognitive ability, yet struggled to concentrate on simple tasks. Dehydrated young men in a similar study experienced difficulty completing mental tasks, especially in areas of vigilance and memory, as well as anxiety and tension. Alterations in mood were greater in women than men, both at rest and during exercise.
In 2019, research conducted at Swansea University in Wales studied the effects on minor hypohydration (water loss of less than 1% body weight) on physical and mental performance through the measurement of central nervous system function, cardiovascular function, and mood. When participants consumed water, compared with when they were mildly hypohydrated, they had improved mood and increased neural activity when faced with a demanding task.
A 2019 study conducted by Biofortis, Mérieux NutriSciences found that hypohydration and thirst were consistently associated with increased negative emotions. Data showed that a reduction of more than 2% in body mass due to dehydration affected mood, fatigue, and alertness in study participants. Negative emotions such as anger, hostility, confusion, depression, tension, fatigue, and tiredness increased with dehydration of 1% or more and fluid deprivation.
"Dehydration has significant negative effects on physical and mental performance, but the evidence from these studies suggests that even minor hypohydration can adversely affect your mood and your ability to concentrate," says Joshua Thurman, M.D. "Some studies have even shown a benefit in drinking extra water for mood and concentration, although this correlation is still uncertain. Nevertheless, it is clear that inadequate hydration can make mood and concentration worse."
So do your mood a favor and stay hydrated!
ABOUT OUR EXPERT
Dr. Joshua Thurman, MD is a board-certified nephrologist and Professor of Medicine specializing in renal medical diseases and hypertension at the University of Colorado School of Medicine. He received his medical degree from the University of Chicago Pritzker School of Medicine and his undergraduate degree from Harvard University. He has been in practice for more than 22 years.