Researchers have discovered that drinking a particular brain-boosting beverage can restore your depleted intellectual abilities, improve your mental focus, banish fuzzy cognition and even change the way your neurons fire off signals to each other.

When I call water a wonderful brain elixir, I’m not exaggerating much, because research shows downing a humble glass of the stuff can make a world of difference in how your brain works. On the other hand, running short takes a terrible toll.

And it’s a fact that too many of us don’t top off our tank often enough.

Almost everyone should be drinking more water. Especially if you’re getting on in years or you’re a caregiver to someone who is, you should be alert to this problem. As we get older, too many people become less sensitive to the need to replenish their fluids.

The Danger of Dehydration

Some of the latest research on dehydration started when Georgia Tech researcher Matt Wittbrodt got interested in what happens to steel workers at a steel plant where the atmosphere is chokingly hot and the workers have to wear layers of protective clothing.

In the first round of tests, Dr. Wittbrodt and the other scientists found that when sweaty workers don’t drink water and became dehydrated, liquid-filled areas called ventricles expand. This occurs because the brain is pulling in extra cerebrospinal fluid – which also occurs during Alzheimer’s disease.1

Brain scans showed that when you’re dehydrated, not only do the brain’s ventricles react and change shape, the firing pattern of the brain’s neurons is also altered.

“The areas in the brain required for doing the task appeared to activate more intensely than before, and also, areas lit up that were not necessarily involved in completing the task,” Dr. Wittbrodt says. “We think the latter may be in response to the physiological state: the body signaling, ‘I’m dehydrated’.”

In some of the Georgia Tech experiments, dehydrated participants were asked to push a button every time a yellow square materialized on a video screen. The job was purposely boring to homogenize the results with each test subject.

“It helped us to avoid the cognitive complexity behind elaborate tasks and strip cognition down to simple motor output,” Dr. Wittbrodt said. “It was designed to hit essential neural processing one would use to make straightforward, repetitive movements.”

As you might expect, as the people in the study were made thirstier and hotter, their performance in pushing the button went downhill.2

In their research on how dehydration affects the mind, the Georgia scientists also reviewed other studies. From that review, they conclude that while there’s no definitive moment when dehydration starts to significantly harm your mental performance, once you’ve lost water amounting to about two percent of your body weight, you start to have some “severe” mental impairments.3

They also warn that as you get older your sense of thirst generally declines, so unless you consciously focus on drinking enough water you are more likely to become dehydrated when the weather’s hot.

Another complicating factor: With age, your kidneys can’t concentrate urine as well so you also generally retain less fluid. And if you’re carrying around extra body fat, that also reduces your water reserves.

A Way to Survive Strokes

Researchers at Johns Hopkins report a further benefit to staying hydrated – it improves your chances of surviving a stroke.

In the Hopkins study, scientists looked at the test records of 168 people suffering ischemic strokes (caused by blood clots) admitted to the Johns Hopkins Comprehensive Stroke Center. It turned out that half of them were dehydrated when they went into the hospital.

The researchers discovered that the dehydrated patients had four times the risk of their conditions deteriorating compared to the well-hydrated stroke victims.4

Based on their findings, the Hopkins researchers say that most stroke victims should be given enough water to relieve their dehydration unless they are having severe kidney problems.

So. . .need a drink? The answer is probably yes.


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3430653/
  2. https://www.ncbi.nlm.nih.gov/pubmed/30136401
  3. https://www.ncbi.nlm.nih.gov/pubmed/29933347
  4. https://newsroom.heart.org/news/dehydration-linked-to-worsening-stroke-conditions?preview=ed90