Smoking and Acidity of Blood

[Guest guest]

I hope Cyndi will provide the reference asked for about the

" acidifying " effects of tobacco on the " body " (by which I assume she means the

blood.)

I would like to see a chemical mechanism for this, as well as some in vivo

evidence that the pH of the blood actually lowers for a longer duration than

that which would be immediately corrected by adjusted respiration.

As far as I can see, the main mechanism by which this could occur would be

carbon monoxide's combination with oxygen to increase carbond dioxide levels:

2 CO + O2 --> 2 CO2

The increase carbond dioxide would generate cabonic acid:

CO2 + H2O --> H2CO3

Carbonic acid would increase the acidity of the blood mildly by producing H+

ion and bicarbonate ion:

H2CO3 --> H(+) + HCO3(-)

However, the blood quickly responds to temporary increases in acidity by

increasing the respiratory turnover of carbond dioxide. As carbond dioxide

expiration is increased, the equilibrium for the formation of carbon dioxide

from

bicarbonate is shifted rightward, meaning carbon dioxide increases and

bicarbonate ion decreases:

H2CO3 --> CO2 + H2O

Thus, the acidity immediately decreases.

The pH of the blood is very tightly controlled, and no temporary factor

influences it with significance in the absence of a metabolic or respiratory

malfunction which leads to acidosis or alkalosis. The blood contains several

buffer systems, one of which is a true buffer system in the chemical sense

(proteins function as both H+ and OH- acceptor/donors), and the others function

as

more loosely defined buffer systems in that they prevent changes in the pH (of

which the bicarbonate system mentioned above is an example.)

It's possible that some of the chemicals in tobacco would have independent

effects on breathing rates that would affect this " buffer " system. However,

moderate increases in H+ ions would be adsorbed on circulating blood proteins,

and significant increases can be excreted renally, etc.

pH is not something that can be changed easily in the blood. Someone had

posted this great article here once before:

http://www.usyd.edu.au/su/anaes/lectures/acidbase_mjb/acidbase.html I don't

remember whether I found it, or Heidi,

or someone else when we were discussing acids and bases once before. This

was the first thing I saw on the net that actually treated acids and bases

honestly and with science. Even though it's pretty old, it's apparently updated

where relevant, and it closely conforms to what you'd find in a new physiology

book.

Unfortuantely, much of the stuff on the net is driven by attention to a

single one of varying researchers who did acid/base work a long time ago when

measurement methods were extremely inaccurate, and who formed big theories to

explain the pH variation in their different patients, without ANY attention to

the

prevailing accepted blood pH science in all the work done collectively. It

makes little sense to ignore this science while accepting at face value work

done before the pH electrode was around as a measurement tool!

If Cyndi or anyone could provide information on smoking's effect of blood pH

I'd be interested to read it.

Thanks!

Chris

[Guest guest]

>Unfortuantely, much of the stuff on the net is driven by attention to a

>single one of varying researchers who did acid/base work a long time ago when

>measurement methods were extremely inaccurate, and who formed big theories to

>explain the pH variation in their different patients, without ANY attention to

the

>prevailing accepted blood pH science in all the work done collectively. It

>makes little sense to ignore this science while accepting at face value work

>done before the pH electrode was around as a measurement tool!

I agree with however, in one sense I agree with the " acidifying "

arguments. Some foods do " TRY " to make the blood more acid, in that

the kidneys have to work to remove substances that, if not removed,

would make the blood more acidic. One isomer of lactic acid is a culprit

in this ... acidopholus bacteria make that isomer, and most people do

in fact excrete it so fast it never causes acidosis, but the urine becomes

more acidic, and folks who have some metabolic problem don't excrete

if fast enough so it can be said that it " tends " to make the blood

acidic. Exercise does that too, and a few other things (smoking might

be in there too, and meat eating). The folks that believe in

acidifying foods are measuring acid in the urine or saliva, where

it is dumped ... but that doesn't mean the blood actually goes

acid for any length of time.

That said, it doesn't follow that all the acidifying substances are

evil. But I have found that if I eat the so-called alkaline foods

with the so-called acidic foods, I generally feel better ... I think

they do balance each other out in some chemical sense. So I

always have kimchi with my meat.

Heidi Jean