(See Part 1 in a previous edition of The Enterprise for the introduction to this article)
The Bigger Picture: Why Does Water Affect Mood at All?
This study doesn’t stand alone. A broader body of peer-reviewed evidence connects hydration status to mental and emotional function.
When dehydration reduces body mass by more than 2%, it has been consistently reported that mood is influenced, fatigue is greater, and alertness is lower, though the effects on cognition have been less consistent.
Current findings in the field suggest that particular cognitive abilities and mood states are positively influenced by water consumption, with the impact of dehydration on cognition and mood being particularly relevant for those with poor fluid regulation, such as the elderly and children.
Dehydration of 2% or more body mass loss can increase perception of fatigue, induce impairment in cognitive functions such as memory and attention, and alter mood. Researchers have also begun investigating the consequences of mild dehydration, well below the 2% threshold, that many people may be experiencing in their daily lives without realizing it.
On the neurological side, despite the lack of behavioral changes in cognition, neural activity in brain regions involved in attention and executive function has been shown to increase when individuals are mildly dehydrated compared to when they are fully hydrated, suggesting the brain works harder just to maintain normal function when water is insufficient.
Key Takeaways: It’s Not Just “Drink More Water”
One of the most important insights from the Pross et al. study is that hydration recommendations should be personalized. The results suggest that an increase or decrease in habitual water intake has, respectively, an improving or worsening effect on mood and sensations, depending upon an individual’s habitual drinking habits.
Put simply: if you normally drink a lot of water, cutting back, even moderately, can dampen your mood in ways you might not immediately associate with thirst. And if you’re a habitually light drinker, simply drinking more can lift the mental fog and fatigue you may have learned to accept as normal.
Increasing water intake has a beneficial mood effect, especially on sleep/wake feelings, whereas restricting water intake can deteriorate mood, and even though the results were observed in young adults, they can still be of importance to the healthy aging population.
Conclusion
The science of hydration and mood is still evolving, but the evidence is clear enough to take seriously: water intake shapes how we feel, and the effect depends on what your body is used to. Whether you’re a habitual high drinker whose mood dips when you can’t get enough, or a low drinker who has quietly lived with unnecessary mental fatigue, your water glass may be more powerful than you think. The next time you feel irritable, foggy, or worn out, it might be worth asking when you last had a drink of water.
Note: For references, see the article posted at www.LifeandHealth.org.
(Submitted by Betty Dean. Written by Ezra Otieno, MPH. Used by permission from www.LifeandHealth.org. Courtesy of LifeSpring — Resources for Hope and Healing, Stuart, VA)
