# pH level in human body [closed]

For my alkaline diet, I need to maintain a pH that's above 7, I need to achieve the objective like this:

I have eaten 300 g of grapefruit (pH = 13), and eaten 70 g of chocolate (pH = 5,5). What pH level have got my body from both these products?

## closed as off-topic by Martin - マーチン♦May 22 '17 at 12:27

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "Personal medical questions are off-topic on Chemistry. We can not safely answer questions for your specific situation and you should always consult a doctor for medical advice." – Martin - マーチン
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• please read at least 1st paragraph of en.wikipedia.org/wiki/Alkaline_diet – mykhal May 22 '17 at 9:16
• please note grapefruit is acidic, pH between 3 and 4, according to publicly available info. – mykhal May 22 '17 at 9:20
• unfortunately this image stating grapefruit pH 13 is wrong, see scholar.google.com/scholar?q=grapefruit-pH&hl=en – mykhal May 22 '17 at 10:14
• I wonder why don't you believe your chemical sensors in the tongue, that tell you, by sour taste, that grapefruit is acidic. Then, probably your bad or good feelings are caused by something else than acidity / pH. – mykhal May 22 '17 at 10:18
• Human blood maintains a pH of about 7.3 very consistently. For example if the pH of your blood drops to even 7.1 you're either dead or looking at a ventilator. Maintaining a blood pH not reasonable or practicle, your body already does it automatically. – A.K. Jun 24 '18 at 0:25

Additionally, the body has several of mechanisms to maintain homeostasis in the blood and extracellular fluid. So what you consume does not have the final effect on pH of your body as this is tightly regulated around the 7.35-7.45 pH range.

The most important way that the pH of the blood is kept relatively constant is by buffers dissolved in the blood. The most important buffer system in the body is the carbonic acid-bicarbonate buffer:

$$\ce{2H2O(l) + CO2(g) <=> H2CO3(aq) + H2O(l) <=> H3O+(aq) + HCO3-(aq)}$$

Other organs help enhance the homeostatic function of the buffers. The kidneys help remove excess chemicals from the blood, It is the kidneys that ultimately remove (from the body) H+ ions and other components of the pH buffers that build up in excess.

The lungs also play a big role to help control the pH of the blood. The increased-breathing response helps to counteract acidosis (the pH-lowering effects) by removing CO2, a component of the principal pH buffer in the blood vice versa.

This question has no answer, from two main reasons.

### Chemistry does not work that way

It's impossible to calculate resulting pH of solution obtained by mixing known volume or mass or amount of substance of solution A with pHA and known amount of solution B with pHB without knowing composition of substances in those solutions, and their acido-basic properties (pKa).

### Biology does not work that way

Your body has balance systems to preserve proper internal parameters (homeostasis). If you are in hot environment, you begin to sweat, etc. If you are in cold environment, you start to shiver, etc.

In you stomach is strongly acidic environment, because of hydrochloric acid produced by "proton pumps". In other parts of your digestive system, duodenum, the acid is intentionally neutralized and pH is kept slightly alkaline.

Another, maybe more important issues of your question have been discussed just below it.

• Blood pH is very tightly controlled to be 7.35-7.45. Any deviation from this is going to result in serious medical issues. The alkaline diet you refer to is dangerous unscientific nonsense – Waylander May 22 '17 at 11:33
• @Waylander I fully agree, but you might've commented on the wrong post! – orthocresol May 22 '17 at 18:51

Your body's pH will stay the same! Thankfully our bodies are able to regulate our pH levels or else we would be in major trouble as bodily functions only work within set pH levels.