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drink water, orange juice or Cola before eating?

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drink water, orange juice or Cola before eating?

Postby MrMistery » Sun Aug 20, 2006 9:54 am

Any biology book will tell you that it is not good to drink water before you eat because "gastric juice is dilluted and digestion will be harder". What does that mean? The enzyme quantity is the same, isn't it? why does the extra water count?
Few people can actually reason through it if you ask me. According to my own opinion, there are 2 things that contribute to this:
1. pepsin has an optimum pH around 2-3; the adding of water will increase the pH from 2 to 4-5(depending how much water you drink, of course)
2. the extra solvent will decrease the rate of the substrate molecules hitting the enzyme molecules.

Ok, now the pH of Cola, according to them, is 2.71. When i measured myself, i got 2 on the nose. The pH of orange or lemon juice can be even lower, about 1.5-2.

My question is, is number 2 enough to actually make a difference or because the pH is so close to that of the gastric juice your digestion will be ok.
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Postby Jennifer » Mon Aug 21, 2006 1:44 am

I definately understand where you're coming from. I like the hypothesis. I definately think that different substances you drink before eating would have an effect on digestion. Even a small difference in pH can mean a big difference in digestion. The enzymes responsible for digestion may have similar pH numbers to the consumed substance, however the purpose of the enzymes can be completely different.
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Postby victor » Wed Aug 23, 2006 12:11 pm

Hmmm.....what I think is like this...
Drink water before eating of while eating have either good and bad effect. If you drink it too much, well, as you've said...it will raise the pH of gastric juice thus lowering the optimality of pepsin enzyme. Beside, by the raised pH, it's also possible to have some pathogenic bacteria which don't killed by gastric juice.
If we don't drink before eating, it will be hard for us to swallow the food...it's too "dry" in esophagus.

Second, how about cola...well, based of the cola's pH, it's possible for us to get our pH lowered to 1.5 - 2....but remember that the thing that makes cola become acidic is carbonic acid, H2CO3 which will get dissociated into H+ and bicarbonate ions...which then, will get dissociated again into CO2. I think that, by excessive amount of CO2 is not good for our somach, especially before eating because there'll be a pressure difference which indirectly affect the diaphragm and causing "hiccups"..."lol"

But, I don't think that the pH of cola is about 2...wow, it's about 100 times more acidic compared to vinegar....
Oh, any info about the sucralose (chlorine derivative from sucrose) which is used in cola?? "mrgreen"
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Postby MrMistery » Wed Aug 23, 2006 6:22 pm

I was thinking about what you said victor. When i measured the pH however, and i got 2, i said "Hey, even if i got it wrong and it is about 3, it is still much more acidic than mineral water which has a similar CO2 concentration according to my tongue CO2 detector :D "
After some research, i realised that Cola contains H3PO4 which actually gives it's incredible acidic pH. So i did an experiment: shaked all the CO2 out of the Cola and then measured the pH. Still somewhere between 2 and 3. So the H2CO3 has only a minor contribution.

About the fact that the esophagus is too dry if you don't drink some water. Well, the esophagus mucose membrane secrets mucus. But it depends on what you eat. If you eat raw flower, yeah, you should drink some water with it :d
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Postby loveangel » Fri Aug 25, 2006 10:32 am

ahhh.. now i know, ty!
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Postby mcar » Fri Mar 06, 2009 7:59 am

I didn't see he asked for the aphrodisiac drug :roll:

When I read the question, I immediately thought that too much water may increase the gastric volume thus making digestion slower, but then I realized what if the situation is depending on our health conditions? what if certain people with metabolic alklosis or acidosis conditions have to be watched for the type pf food that they eat since it might alter also their acid-pH balances? well, just an idea :wink: .
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Re: drink water, orange juice or Cola before eating?

Postby Vino » Fri Mar 06, 2009 7:28 pm

lindow 195 must love aphrodisiacs!

Have you heard of what?!
Watch it MrMistery.
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Postby mcar » Sat Mar 07, 2009 2:41 am

I see that many really like to open up other topics huh? :wink:
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Postby MrMistery » Sat Mar 07, 2009 5:43 pm

sorry about that. Just spam that went unnoticed.
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Postby MichaelXY » Wed Mar 25, 2009 7:36 am

lol...
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Re: drink water, orange juice or Cola before eating?

Postby Opus » Fri Jun 05, 2009 11:41 pm

Any biology book will tell you that it is not good to drink water before you eat because "gastric juice is dilluted and digestion will be harder". :roll:

??? Where ARE these s***ty textbooks, I've NEVER seen this. This is nonsense.

The FACT is, if your stomach acid is diluted by food or drink, IT JUST MAKES MORE.
Your stomach is not a passive beaker in chemistry class - it is a living organ and it adjusts to its environment.
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Re: drink water, orange juice or Cola before eating?

Postby Justinaschwarz » Tue Sep 13, 2011 8:23 am

and i think it should also depend on the person himself, how he feels.. if drinking water with meals, before meals, or after meals is not harmful for him then everything is ok )
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