Many of us try to drink the recommended 6-8 glasses of water per day because we’ve heard it helps with our skin and other aspects of health. But you may be even more vigilant about keeping that Nalgene filled if you knew that even the slightest dehydration can affect your mental awareness.

Business Insider’s Drake Baer takes a look at some of the studies related to hydration and brain functionality, and the takeaway is clear: Drink more water if you want to perform your best at anything, even if it involves spreadsheets instead of wind sprints.

As University of Texas neuroscientist Joshua Gowin writes in Psychology Today, “Brain cells require a delicate balance between water and various elements to operate, and when you lose too much water, that balance is disrupted. Your brain cells lose efficiency.”

Staying properly hydrated is just as important for those who work all day at a computer, as it is for marathon runners.

In fact, losing just 1% of body weight due to not drinking enough water can decrease both concentration and alertness, reports a separate piece in Psychology Today. Simply providing access to water has been shown to increase both attention and memory in school-aged children, who are generally more prone to dehydration than adults.

Dr. Gowin agrees: “Dehydration can impair short-term memory function and the recall of long-term memory. The ability to perform mental arithmetic, like calculating whether or not you’ll be late for work if you hit snooze for another 15 minutes, is compromised when your fluids are low.”

If that’s not reason enough for you to drink more water, consider a 2012 study from the University of Connecticut’s Human Performance Laboratory. Tests gauged the comparative abilities of both properly hydrated and dehydrated subjects at several cognitive tests.

This study found that mild levels of dehydration in young women seemed to produce greater levels of headaches, fatigue, and difficulty concentrating, as well as bigger mood swings—but no measurable decrease in cognitive function. However, young men experienced cognitive issues, including problems with vigilance, memory, anxiety, and tension.

Study co-author Harris Lieberman noted, “Dehydration affects all people, and staying properly hydrated is just as important for those who work all day at a computer, as it is for marathon runners.”

Lieberman’s partner on this study, Lawrence E. Armstrong, added, “Our thirst sensation doesn’t really appear until we are 1 or 2% dehydrated. By then dehydration is already setting in and starting to impact how our mind and body perform.”

So really, the key is sipping water consistently throughout the day, before you notice that you’re thirsty.

And what about that old wisdom that coffee dehydrates you? That’s not necessarily the case, according to a different study from the University of Birmingham.

Study author Sophie Killer said, “It’s well understood that if you drink coffee habitually you can develop a tolerance to the potential diuretic effects of coffee.”

Phew. So it’s settled: More water and more coffee.

[via Business Insider]

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