The Impact of Dehydration (Part 2)
- Dr. Melissa Adams
- 14 minutes ago
- 4 min read
In last week's blog, we covered dehydration and its impact on pain, post-surgical complications, and errors or incidents while driving. We learned that even very slight dehydration can create difficulties for us, even make us experience more pain or more intense pain.
This week, we will be discussing dehydration and its impact on your cognitive abilities and we will touch on a potential placebo effect.
Several studies have shown that very slight dehydration (losing just 0.66-2% of body mass), can create difficulties with things such as athletic performance, mood, our ability to remain focused on a task, executive functioning, and our ability to move in a coordination fashion. They have shown that children's cognitive functioing improves when they are properly hydrated (so all these kids carrying around water bottles now - that's a good thing for their brain functioning).
This first study is the one which looked at not only cognitive impact of dehydration, but also whether or not there is a possible placebo effect. There were 174 subjects in the study, roughly 50/50 male/female. They were in a room which was 30*C (86*F) for 3 hours during the study.
This study included 2 different capsules that the participants took, one had salt in it (electrolyte capsule), the other had cornflour in it (placebo). There were 3 drink options, no drink at all with their capsule, plain water with their capsule, or taking their capsule with water with food coloring in it.
This combination means there were 6 conditions:
Participants completed various cognitive tests initially, as a baseline. Then after a set amount of time, they consumed their drink (or no drink) with a capsule and completed another round of cognitive testing. This process was repeated once more during the study.
The study looked at several things including urine, body mass, utilized a mood scale (agreeableness, confidence, depression, anxiety, and energy), memory evaluations, attention and focus abilities, and reaction times.
When it came to results, there was no difference between genders and no water meant a greater loss of body mass, with no impact from the capsule on this portion.
The results:
Plain Water + Placebo Capsule was best for: Agreeableness
Plain Water + Electrolyte Capsule was best for: Composure and improved response times in cognitive testing
Colored Water + Placebo Capsule was best for: Energy
Plain Water OR Colored Water was best for: Clearheadedness
No significant effects were found with: Elation vs Depression, Confidence vs Uncertainty, Memory
These results were seen with as little as 0.66% dehydration and show that the brain may be prioritizing certain processes in an effort to maintain other processes. Additionally, water alone was not enough to help replace the lost fluid, the electrolyte capsule (salt) was also required. It is interesting that the red-colored water plus the placebo capsule seemed to give people at least a perception of having more energy, indicating a possible placebo effect.
Another study looked at 33 studies concerning cognition and dehydration. They noticed executive functioning (ability to plan, manage emotions, etc), attention, and motor coordination were all significantly impaired.
Again, they noticed not every part of the brain or our functioning is affected equally, it seems those things that are more complex for our brain are affected more quickly and easily, specifically the frontoparietal portion of the brain (executive functioning portion of the brain, often implicated in autism, ADHD, mental health concerns, motor control, etc).
It was also noticed that the perception of thirst is affected, which perhaps means other areas of the brain may be initially impacted. This also means we should not be waiting until we feel thirsty because slight dehydration may impact our ability to even know when we are thirsty.
In this last study, they noticed that after dehydrating people (30*C/86*F room for 4 hours, some had water, some did not, 101 subjects), drinking water improved their memory and their ability to focus their attention. If someone was thirsty, they had worse memory and the more dehydrated they were the less energy they had and they were more anxious and depressed but these affects decreased when they drank water.
One important thing this study mentioned was that some of the first signs of any subclinical nutritional deficiency is typically psychological in nature. This means, before blood tests say, "You're dehydrated" or "You're low on Vitamin B" or whatever, your body and brain is already struggling with a deficiency and that is most likely to show up as something psychological in nature such as anxiety or depression.
The results:
Water resulted in faster response times in some testing, but not in others.
Water was helpful for immediate memory but not delayed memory, however, being thirsty resulted in poorer memory (both immediate and delayed).
Water did not have a significant impact on anxiety, energy, or depression and did not significantly impact response times.
It is interesting to note, again, that the perception of thirst seems to have an impact on some cognitive abilities and mood.
Through these studies, we can see that even a very small amount of dehydration can have a significant impact on our cognitive abilities. Our brains seem to be quite finicky and picky about being properly hydrated and if we are not properly hydrated, we quickly experience a decline in function.
So ... if you aren't yet carrying around a bottle of water and if you aren't drinking enough water, here's your sign - drinking water can help with your cognitive abilities, decrease your pain, decrease your driving errors, and even help to decrease post-surgical complications!
Blog sponsored by One More Step Foundation
This is not medical advice, always ask a chiropractor if chiropractic care is appropriate for you, and your preferred healthcare provider before making dietary, supplement, or lifestyle changes.
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