Hydration has a significant impact on brain health over the course of a lifetime.
Mainstream news media reports and citations from some physicians indicate that chronic dehydration might be as high as 75 percent in the American population. The notion that up to three-quarters of the people in our country aren't adequately hydrated is disturbing, but not shocking. The act of drinking enough water isn't difficult for people who have sufficient access to it, but the desire to do so isn't there for many. Yet consider this: nearly three-quarters of human brain mass is comprised of water. So, if up to 75 percent of us don't drink enough water daily, how does that impact a brain almost entirely made up of the stuff? In a word – poorly.
When it comes to dehydration, people hear most often of the adverse physical effects or symptoms. It stands to reason that if dehydration can have such a terrible impact on the body, the brain is affected too. One will likely begin to experience the mental influence of dehydration before the most severe physical consequences occur.
Recall a time in your life when you felt dehydrated. What was the first sign or symptom to present itself? Beyond feeling thirsty, you likely first noticed an initial symptom associated with your head. Feeling dizzy, lightheaded, or experiencing a headache are common initial symptoms of dehydration for many people. To those of us who study brain health, these signals come as no surprise. However, considerable volumes of research have shown that dehydration negatively affects cognitive performance as well. And these deficits may or may not be subjectively experienced. You may not even realize this kind of dysfunction.
Even slight percentage decreases in brain hydration can result in much more significant percentage decreases in cognition. Consider this – just a 2 percent decrease in brain hydration can lead to short-term memory loss. Longer-term dehydration can cause the shrinkage of brain cells. Over time, brain cell shrinkage can accelerate the brain's aging process and lead to degenerative cognitive conditions such as Alzheimer's Disease and dementia.
Long-term dehydration can have a catastrophically negative impact on brain health over the course of a person's lifetime. So, since staying properly hydrated is a modifiable (something we can control) risk factor for most of us, we should focus on permanently fixing the problem by changing our habits – and not just during the summer months. It may surprise you to know that the risk of dehydration can be just as high during the cold winter season – because the experience of thirst may not present itself when the seasonal temperature is lower. Also, since thirst is a sign that a person is already experiencing the effects of dehydration, it's not a good signal for dehydration prevention.
To put yourself on the best course for adequate hydration and dehydration prevention, consider scheduling your water consumption to start. For some people, that can include a commitment to drinking a glass of water when they wake up in the morning, before each meal and snack of the day, and before bedtime. There are also some good hydration reminder apps for smartphones that can send you a notification when it's time to drink more water, and they measure your needs according to your weight, height, and activity level. Speaking of activity level, drinking water throughout an exercise session or immediately afterward is also imperative if you're an active person (and you should be!). We lose a considerable amount of water as we sweat, so those who engage in high-intensity exercise will need to place an even greater focus on their water intake and hydration needs.
Finally, I must point out that not all liquids are created equal. Though water isn't the only hydration source available, it is typically safe, effective, and readily available. Water is inexpensive and calorie and caffeine-free, while many commercially marketed hydration beverages are not. So read labels carefully. Armed with an understanding of how dehydration negatively impacts brain health across the lifespan and some diligence in ensuring you're appropriately hydrated daily, you'll be well on your way to reducing the risk of premature cognitive decline down the road. So let’s raise our glass and drink up!
Sources:
https://www.ncbi.nlm.nih.gov/books/NBK555956/