Saturday, 26 October 2013

Alcohol is Dehydrating and then some

After being side-tracked by the iron issue, including cast iron cookware, and NSAIDs, especially aspirin, I’m back to finish my dehydrating series with this article about alcohol (ethyl alcohol or ethanol).  After all, it’s one of the big three.  I got started on this dehydration issue when I heard a claim in a television programme that caffeine isn’t dehydrating.  My research confirmed that it is dehydrating.  Next, I looked into the effects of sugar on dehydration because it’s often mixed with caffeinated products and I concluded that it aggravated the situation caused by caffeine and could even cause dehydration on its own.  Now I’ll look at alcohol, especially because sometimes it comes with sugar (e.g., wine) and sometimes it’s mixed with caffeine and sugar (e.g., Irish coffee).  I think it’s generally agreed that alcohol is dehydrating, but why and to what end?  Let’s take a look.
Alcohol Requires No Digestion
Alcohol does not get digested in the gut.  It goes directly into the bloodstream.  Most of it is absorbed from the upper part of the small intestine, up to 80 percent, but some even gets absorbed from the stomach, especially if empty.  About 10 percent of the alcohol will exit the body through respiration and elimination.  But what happens to the rest of the alcohol once it gets in the bloodstream?
Kidneys Go into Overdrive
Sugar and caffeine are diuretics and so is alcohol.  They all act in a different manner though.  The case with alcohol is that it inhibits the release of the antidiuretic hormone, commonly known as arginine vaopressin (AVP).  AVP is involved in regulation of water, glucose and salts in the blood.  It helps maintain homeostasis.  Alcohol reduces the secretion of AVP from the posterior pituitary gland “by blocking voltage-gated calcium channels.”  So here we go again with electrolyte imbalance, but this time the focus is on calcium.  Remember?  With sugar it was magnesium and with caffeine it was sodium and potassium.
When AVP secretion is diminished, the kidneys are no longer as able to reabsorb water, and therefore, urine production is increased.  This result is very effective because it increases urine output substantially.  It has been shown that with five units of alcohol (about 50 grams) in eight ounces of water, the output will be up to four times as much.  But even drinking low alcoholic drinks (one unit per bottle, such as beer), urinary output will be increased.
Because I’m focusing on the dehydrating effects of alcohol, I’m not going into how alcohol is processed in the liver or the detrimental effects it has on the body.  I’ve just covered the basics with the effect alcohol has on the kidneys and water loss, but as in my other dehydration articles, I’d like to bring this discussion down to a cellular level because that is where a lot of important action occurs.  When it comes to alcohol and dehydration, there is a lot of evidence that brain cells are prime targets.
Alcohol Particularly Dehydrates Brain Cells
Image credit with thanks: Neuroscience for Kids (wow, I never had this when I was a kid!):  Alcohol and the Brain
I’d like to take this opportunity to remind the reader that alcohol is a poison that passes the blood brain barrier.  In other words, the alcohol that is consumed touches the brain directly.  Once in the brain, it changes the neurons.  For one thing, it makes them less excited.  Dims the light.
Photo image credit with thanks:  Excitable Cells
As mentioned above, alcohol blocks voltage-gated calcium channels which suppresses the secretion of the AVP hormone leading to excessive urination. Voltage-gated calcium channels are found in the membranes of excitable cells.  Cells are called excitable when they can generate an electric current (as shown in the photo).  Excitable cells are found in glandular tissues which secrete hormones such as the pituitary gland but they are also found in muscle cells.  Then there’s the brain which has lots of excitable cells in the form of neurons.  It’s not just the excitable cells in the pituitary gland that are affected by alcohol.  In particular, alcohol has been shown to have a substantial affect on the neurons in the brain.
There’s a two prong analysis that could be done on this topic at this stage:
1.      Explain exactly what effect alcohol has on the neurons in the brain, specifically in relation to the voltage-gated calcium channels.  In other words, what effect does this blockage have on brain cells and brain function such as memory, consciousness, cognition, etc.
2.     Explain what the effects of dehydration are on the brain.
One research project showed how in the context of a highly interconnected network of neurons, the voltage-gated calcium channels are a fundamental component of brain mechanisms that underlie states of consciousness as well as perception and cognition.  Applying a little logic, I come to the conclusion that alcohol negatively interferes with important brain functions such as the ability to be aware of and respond to the environment.  But, it doesn’t take Einstein to notice the effects of alcohol.  It changes consciousness to one of less consciousness.  It blurs perception and cognition.  “Don’t drink and drive” is promoted for good reason.
As for the second point, dehydration of the brain has been linked to moodiness, Alzheimer’s, depression and other mental disorders.  The hyperlinks are to my blog articles on these subjects, but there’s lots of information online making the connection with dehydration.
What I hope this article has shown is that alcohol is dehydrating and the mode of action for this dehydration is that it blocks voltage-gated calcium channels causing excessive urination.  But besides being in the kidneys where this dehydration is controlled, these channels are found in other excitable cells including the billions in the brain.  This, in turn, is a dual-action attack on our mental abilities:  (1) interference with neuron activity due to electrolyte imbalance and (2) dehydration.  Frankly, I don’t believe the research that says moderate drinking is preferable to abstinence and perhaps even helpful in avoiding dementia in old age and other similar claims.  The logical evaluation of the evidence of the effects of alcohol on the body does not lend to this conclusion.  Alcohol is dehydrating and dehydration is unhealthy, especially for the brain.  And then there’s the added cellular damage caused by alcohol.
My view is that the mental aspect of relaxation and enjoyment that some people find from drinking moderate amounts of alcohol is what may lead to a positive result.  The mind is a powerful thing and positive thoughts may even outweigh the negative physical results of alcohol consumption.  It’s not an ideal situation though.  Learning how to relax and enjoy life without drinking alcohol would be preferable from an overall health perspective because with drinking alcohol, one is taking a risk of adverse reaction, especially for those with alcoholism in the family or sensitivities for other reasons.
That’s all folks for the dehydration series.  Many people have coffee at meals and breaks, add sugar to the coffee and eat the usual sugary affairs on offer everywhere and then like to end the day with a glass or two.  I used to be guilty of this myself.  Add to this a reluctance to drink water, multiply it by many years and we can see how a picture of ill health might easily develop because of dehydration.  Keeping hydrated is extremely important in our toxic modern world and I believe it’s wise to avoid “the dehydrators” as much as possible.