One can read on different forums that the intake of coffee is reducing the hydation process. As anyone a proof/explanation of this? Thanks
cafeine and dehydration
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Caffeine is a diuretic. This much is true. However, if you're accustomed to drinking X mg/day, your body will have equilabrated at that level. If your consumption stays relatively stable, you're not going to be dehydrated. If, however, you suddenly increase your consumption to 4X, without increasing your water intact, you're likely to experience some degree of transitory dehydration.
However, I have to say I've never seen anybody in the ER with a significant degree of dehydration strictly from caffeine. Caffeine and laying in the sun, certainly. But not caffeine alone.
However, I have to say I've never seen anybody in the ER with a significant degree of dehydration strictly from caffeine. Caffeine and laying in the sun, certainly. But not caffeine alone.
OP
Thanks dirty dog. I am used to 2 huge cups of diluted coffee in the morning + one litre of water before the first dive on liveboard, so on the safe side
fire_diver
Contributor
Drinking more water with the caffeine won't help. Caffeine is a diuretic because it's a vaso-constrictor. This is also why it causes an increase in blood pressure. Your body sees the increase in BP and tries to correct it by dumping excess water into the bladder.
dreamdive
Contributor
There is a lot of myth regarding hydration and DCS out there. Hydration is important but so is timing! Physiologically, POST-hydration is more important than pre-hydration (provided that one does not enter the water in a very dehydrated state)
Here is some information from:
IPE ? Immersion Pulmonary Edema | Add Helium
IPE Immersion Pulmonary Edema
"Why would there be excessive pressure in the pulmonary capillaries/vessels?
A possible explanation might be from over-hydration. When we immerse in water up to our necks, we shunt about 700 ml of blood from the periphery to the central core, i.e. the central vasculature. When blood gets shunted suddenly to the core, the heart and great vessels have to accommodate this additional volume. Usually, vessels will attempt to dilate. Increasing the diameter of a vessel will result in a decrease in pressure. Without this dilation, the pressure remains high.
Prior to an immersion, our vasculature might alreadybe full when well hydrated. Although adequately hydrated on the surface, with immersion we might suddenly become over-hydrated. Typically our hearts are sensing this excessive volume and will signal the kidneys to get rid of water and salt to decrease the volume. The signaling mechanism is via hormones of increased Atrionatiuretic Peptide (ANP) and decreased Vasopressin. The results are not immediate, as our kidneys need a little time to complete the task.
By the way, the effect of immersion is independent of depth. Going deeper does not increase the effect of immersion. Thus when experiencing IPE, going shallower will not alleviate the symptoms.
Cold water has also been thought to predispose to IPE. Cold water typically shunts blood from the periphery to the core thereby exacerbating the effect of immersion. Similarly, a wet suit or vest that is too tight may squeeze the blood from the periphery to the central core.
The scientific community is not absolutely certain what the true cause of IPE is. It is quite possible that it is not an isolatable cause but rather a combination of factors.
What this basically states is that one can be somewhat dehydrated and not have issues because the central shunting of blood to the core caused by immersion is preventing it. Diuresis will occur during immersion (that's why we want to pee in our wet suits - and heaven's forbid in our dry suits). Once we get out of the water, redistribution of blood occurs and NOW the body may see a "relative" dehydration. Thus re-hydration post diving appears to be important (not with beer and other alcoholic beverages which also cause diuresis).
The mild diuretic effect of coffee in the morning appears to be an non-issue as others have attested.
Enjoy
---------- Post added September 20th, 2014 at 10:36 AM ----------
One more thing I found:
Hydration
Do: Re-hydrate immediately after the dive. It is during the dive, where we lost a lot of our hydration and need to replenish!
Dont: Aggressively hydrate before the dive. Overhydration puts a lot of strain on your heart and actually may put you at risk for developing pulmonary edema. Obviously, if you have a stomach bug and become dehydrated, you need to replenish until you get to euvolemia (normal body fluid volume) again. If you were binge drinking the night before, (another dont, by the way), you need to replenish.
Dont: Hit the bar and load up on alcoholic beverages after the dive. You need to re-hydrate your body first! Be responsible with your alcohol intake when diving! Too much alcohol will not only give you a hangover the next day, but will be dehydrating, as well. Your liver may not metabolize too much alcohol in time before jumping in the water the next day! You basically are diving while intoxicated!
Here is some information from:
IPE ? Immersion Pulmonary Edema | Add Helium
IPE Immersion Pulmonary Edema
"Why would there be excessive pressure in the pulmonary capillaries/vessels?
A possible explanation might be from over-hydration. When we immerse in water up to our necks, we shunt about 700 ml of blood from the periphery to the central core, i.e. the central vasculature. When blood gets shunted suddenly to the core, the heart and great vessels have to accommodate this additional volume. Usually, vessels will attempt to dilate. Increasing the diameter of a vessel will result in a decrease in pressure. Without this dilation, the pressure remains high.
Prior to an immersion, our vasculature might alreadybe full when well hydrated. Although adequately hydrated on the surface, with immersion we might suddenly become over-hydrated. Typically our hearts are sensing this excessive volume and will signal the kidneys to get rid of water and salt to decrease the volume. The signaling mechanism is via hormones of increased Atrionatiuretic Peptide (ANP) and decreased Vasopressin. The results are not immediate, as our kidneys need a little time to complete the task.
By the way, the effect of immersion is independent of depth. Going deeper does not increase the effect of immersion. Thus when experiencing IPE, going shallower will not alleviate the symptoms.
Cold water has also been thought to predispose to IPE. Cold water typically shunts blood from the periphery to the core thereby exacerbating the effect of immersion. Similarly, a wet suit or vest that is too tight may squeeze the blood from the periphery to the central core.
The scientific community is not absolutely certain what the true cause of IPE is. It is quite possible that it is not an isolatable cause but rather a combination of factors.
What this basically states is that one can be somewhat dehydrated and not have issues because the central shunting of blood to the core caused by immersion is preventing it. Diuresis will occur during immersion (that's why we want to pee in our wet suits - and heaven's forbid in our dry suits). Once we get out of the water, redistribution of blood occurs and NOW the body may see a "relative" dehydration. Thus re-hydration post diving appears to be important (not with beer and other alcoholic beverages which also cause diuresis).
The mild diuretic effect of coffee in the morning appears to be an non-issue as others have attested.
Enjoy
---------- Post added September 20th, 2014 at 10:36 AM ----------
One more thing I found:
Hydration
Dont: Aggressively hydrate before the dive. Overhydration puts a lot of strain on your heart and actually may put you at risk for developing pulmonary edema. Obviously, if you have a stomach bug and become dehydrated, you need to replenish until you get to euvolemia (normal body fluid volume) again. If you were binge drinking the night before, (another dont, by the way), you need to replenish.
Dont: Hit the bar and load up on alcoholic beverages after the dive. You need to re-hydrate your body first! Be responsible with your alcohol intake when diving! Too much alcohol will not only give you a hangover the next day, but will be dehydrating, as well. Your liver may not metabolize too much alcohol in time before jumping in the water the next day! You basically are diving while intoxicated!
drrich2
Contributor
Consider the other factors involved. Yes, caffeine has a diuretic effect, I'm told, and if you took caffeine pills (such as some have used to increase mental alertness), I would anticipate your net body water amount would decrease.
But how many divers get their caffeine in pill form?
It's usually in the forum of soda, tea or coffee. Which contain water and thus add water, as well as caffeine, to your system. Which raises the question in terms of hydration as to whether they are '2 steps forward and 3 steps back, or 3 steps forward and 2 steps back?' What's the net effect?
Here's a WebMD article covering hydration. From it:
Now, how all that might be impacted by the immersion diuresis we tend to get diving in water cooler than our body temp. I don't know, but at least tentatively, I consider guzzling soda pop to be hydrating. Considering the amounts I drink some days, and how little else, I think I might be dead if it weren't.
Richard.
But how many divers get their caffeine in pill form?
It's usually in the forum of soda, tea or coffee. Which contain water and thus add water, as well as caffeine, to your system. Which raises the question in terms of hydration as to whether they are '2 steps forward and 3 steps back, or 3 steps forward and 2 steps back?' What's the net effect?
Here's a WebMD article covering hydration. From it:
Now, how all that might be impacted by the immersion diuresis we tend to get diving in water cooler than our body temp. I don't know, but at least tentatively, I consider guzzling soda pop to be hydrating. Considering the amounts I drink some days, and how little else, I think I might be dead if it weren't.
Richard.
dreamdive
Contributor
This from another member from this forum some time ago:
"Common belief used to be that for every cup of caffeinated beverage that you drank, you would pee THREE cups of liquid. Caffeine was thought to be a true diuretic, actually pulling liquid from your tissue, and causing dehydration.
Modern tests have shown that for every cup of caffeinated beverage that you drank, you pee about ½ cup. In other words, you will still get hydrated, but probably not as well as if you drank water.
For comparison, for every cup of water you drink, you pee about 1/3 of it.
So, not a concern in the volumes that we drink."
"Common belief used to be that for every cup of caffeinated beverage that you drank, you would pee THREE cups of liquid. Caffeine was thought to be a true diuretic, actually pulling liquid from your tissue, and causing dehydration.
Modern tests have shown that for every cup of caffeinated beverage that you drank, you pee about ½ cup. In other words, you will still get hydrated, but probably not as well as if you drank water.
For comparison, for every cup of water you drink, you pee about 1/3 of it.
So, not a concern in the volumes that we drink."
AngloFish
Contributor
Caffeine ingestion and fluid balance: a review. [J Hum Nutr Diet. 2003] - PubMed - NCBI
[h=3]Abstract[/h][h=4]BACKGROUND:[/h]Caffeine and related methylxanthine compounds are recognized as having a diuretic action, and consumers are often advised to avoid beverages containing these compounds in situations where fluid balance may be compromised. The aim of this review is to evaluate the available literature concerning the effect of caffeine ingestion on fluid balance and to formulate targeted and evidence-based advice on caffeinated beverages in the context of optimum hydration.
[h=4]METHOD:[/h]A literature search was performed using the Medline database of articles published in the medical and scientific literature for the period of January 1966-March 2002. Subject headings and key words used in this search were: tea, coffee, caffeine, diuresis, fluid balance and water-electrolyte balance. A secondary search was performed using the bibliographies of publications identified in the initial search.
[h=4]RESULTS:[/h]The available literature suggests that acute ingestion of caffeine in large doses (at least 250-300 mg, equivalent to the amount found in 2-3 cups of coffee or 5-8 cups of tea) results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. A profound tolerance to the diuretic and other effects of caffeine develops, however, and the actions are much diminished in individuals who regularly consume tea or coffee. Doses of caffeine equivalent to the amount normally found in standard servings of tea, coffee and carbonated soft drinks appear to have no diuretic action.
[h=4]CONCLUSION:[/h]The most ecologically valid of the published studies offers no support for the suggestion that consumption of caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status. Therefore, there would appear to be no clear basis for refraining from caffeine containing drinks in situations where fluid balance might be compromised.
[h=3]Abstract[/h][h=4]BACKGROUND:[/h]Caffeine and related methylxanthine compounds are recognized as having a diuretic action, and consumers are often advised to avoid beverages containing these compounds in situations where fluid balance may be compromised. The aim of this review is to evaluate the available literature concerning the effect of caffeine ingestion on fluid balance and to formulate targeted and evidence-based advice on caffeinated beverages in the context of optimum hydration.
[h=4]METHOD:[/h]A literature search was performed using the Medline database of articles published in the medical and scientific literature for the period of January 1966-March 2002. Subject headings and key words used in this search were: tea, coffee, caffeine, diuresis, fluid balance and water-electrolyte balance. A secondary search was performed using the bibliographies of publications identified in the initial search.
[h=4]RESULTS:[/h]The available literature suggests that acute ingestion of caffeine in large doses (at least 250-300 mg, equivalent to the amount found in 2-3 cups of coffee or 5-8 cups of tea) results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. A profound tolerance to the diuretic and other effects of caffeine develops, however, and the actions are much diminished in individuals who regularly consume tea or coffee. Doses of caffeine equivalent to the amount normally found in standard servings of tea, coffee and carbonated soft drinks appear to have no diuretic action.
[h=4]CONCLUSION:[/h]The most ecologically valid of the published studies offers no support for the suggestion that consumption of caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status. Therefore, there would appear to be no clear basis for refraining from caffeine containing drinks in situations where fluid balance might be compromised.
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