Depressed or Dehydrated?

I’m continuing with the A to Z Blogging Challenge. Today is “D”. D is for depressed or dehydrated….or both!

Drink eight 8-ounce glasses of water a day. That’s about 2L. I’m sure you’ve heard this before, but do you actually do it? I know I don’t. This 2L is just for a regular day. If it’s hot out, or you are exercising, then you need even more! Chronic dehydration leads to all sorts of problems; fatigue, constipation, high blood pressure, digestive disorders….. I could go on forever. Your body is a bio-electric machine whose major component is water. In fact, the body is 70% water. Of course something is going to go wrong if you don’t get enough of it.

When the body doesn’t get enough water, it has to ration what it does have, which means cutting back on function. This means it takes water from your muscles, bones and brain. Yes, the brain! The brain is 85% water, 2% of the body’s water weight and it receives 15-20% of the body’s blood supply, most of which is water. Thirst is the survival mechanism that we’ve adapted to tell us our body needs more water. Thirst is the warning that occurs before function is too compromised and survival is at risk. The problem is, by the time thirst kicks in, we are already suffering the effects of mild dehydration. Mild dehydration occurs when 1.5% of normal body water volume is lost. That is not a big amount. Thirst is triggered somewhere between a 1-2% loss. By the time you feel like drinking, it has already had an effect on your mind.

Dehydration affects mood, energy and ability to think clearly. A study investigating mild dehydration in men reported that they complained of tension, anxiety and fatigue. On a cognitive test battery, they had trouble with working memory and concentration. It was even worse for women. They reported headaches in addition to fatigue. On the cognitive tests, like the men, women had difficulty concentrating, but they also reported the tasks to be more difficult compared to when they did them fully hydrated.

Why does this happen? There are a couple reasons. One is tryptophan, an amino acid and the precursor to serotonin, a neurotransmitter that contributes to our feelings of well-being and happiness. Tryptophan is an essential amino acid. This means it is essential for life and it cannot be synthesized by the body, so we must get it from our diet. Tryptophan is absorbed from the gut into the blood stream where it is transported to the brain. Here, it must cross the blood-brain-barrier before it can be converted into serotonin. Dehydration impedes the transport of tryptophan across this barrier leading to a drop in brain serotonin levels.

Another reason is histamine, another neurotransmitter. Histamine is responsible for triggering the thirst mechanism and rationing a limited water supply. When you are dehydrated, histamine levels increase. What does this have to do with anything? Histamine stimulates the release of….wait for it….serotonin, norepinephrine AND dopamine. All of which play a role in mood. Low levels of histamine cause high levels of dopamine which have been associated with hallucinations. Too much histamine distorts the release of serotonin, norepinephrine and dopamine causing the “racing mind” feeling.

So there you have it. Depression via dehydration. Are you depressed or just dehydrated? Only you know that answer, but I bet you’d feel better if you drank enough water. I mean pure water, no juice or tea and definitely no coffee or alcohol, those are dehydrating! There is some water in those drinks, but there are also a lot of other things in them that your body needs water to digest. In the end your body will need more water to digest that glass of juice than the juice actually provides. How do you know if you are drinking enough? You can tell by the colour of you urine. A pale yellow means the body has enough water while a deep yellow indicates concentrated urine, a sign of dehydration.

Sources:
PsychCentral
Armstrong et al., 2012