I have seen that soft drinks are harmful to the body due to the very differing level of pH. I have also seen that our aged body become acid through time. And alkaline when young.

The Physiological Power of Water Dr Lair Ribeiro Md FACC

He says it at 19:20

Drinking water should be around 7 ? Or alkaline ? Above it?

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    For the benefit of others, can you please share where you read that the body is alkaline when young and becomes acid through time? Sep 12, 2018 at 9:06
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    Soft drinks are harmful because they're nothing but sugar water. I'm extremely skeptical that the pH of the water you drink has any material effect on the body whatsoever unless you're drinking water that's so extreme in either direction that it burns tissue.
    – Carey Gregory
    Sep 12, 2018 at 14:48
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    Please don't rely on YouTube videos for medical advice (or television doctors, or anyone selling a book with a shortcut to health, for that matter). Also do you have any idea what the pH of the stomach is?
    – Bryan Krause
    Sep 12, 2018 at 15:22
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    As in, basically the same as a soft drink. This stack is not intended for evaluating claims, if you have claims you need to be able to back them up with reasonable references (not just a YouTube video). You could try on Skeptics.SE, but they also have a fairly rigorous definition of what an acceptable claim is.
    – Bryan Krause
    Sep 12, 2018 at 15:34
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    Have to agree with the above comments. But if you document a bit more research (in written form) about advice given out or better yet: research that concludes 'certain pH for drinks should be preferred' this might fit here. Sep 12, 2018 at 19:19

1 Answer 1


The WHO says between 6.5 and 9.5, but mostly due to the pH's effect on operational water-quality parameters. Between 4 and 10.5, apart from possible irritation the effect on humans may not be severe:


Exposure to extreme pH values results in irritation to the eyes, skin, and mucous membranes. Eye irritation and exacerbation of skin disorders have been associated with pH values greater than 11. In addition, solutions of pH 10–12.5 have been reported to cause hair fibres to swell. In sensitive individuals, gastrointestinal irritation may also occur.

Exposure to low pH values can also result in similar effects. Below pH 4, redness and irritation of the eyes have been reported, the severity of which increases with decreasing pH. Below pH 2.5, damage to the epithelium is irreversible and extensive. In addition, because pH can affect the degree of corrosion of metals as well as disinfection efficiency, it may have an indirect effect on health.


Although pH usually has no direct impact on water consumers, it is one of the most important operational water-quality parameters. Careful attention to pH control is necessary at all stages of water treatment to ensure satisfactory water clarification and disinfection. For effective disinfection with chlorine, the pH should preferably be less than 8.

The pH of the water entering the distribution system must be controlled to minimize the corrosion of water mains and pipes in household water systems. Failure to do so can result in the contamination of drinking-water and in adverse effects on its taste, odour, and appearance. The optimum pH will vary in different supplies according to the composition of the water and the nature of the construction materials used in the distribution system, but is often in the range 6.5–9.5. Extreme pH values can result from accidental spills, treatment breakdowns, and insufficiently cured cement mortar pipe linings.

WHO: pH in Drinking-water: Background document for development of WHO Guidelines for Drinking-water Quality. WHO/SDE/WHO/03.04/12.

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    Just to clarify, this is not talking about what pH is healthy to drink, it is talking about what pH is healthy to deliver through municipal water supplies. Indeed, pouring a soft drink in your eyes is likely to be irritating.
    – Bryan Krause
    Sep 13, 2018 at 0:09
  • It's talking about the pH for municipal drinking water supply. So the answer is a combination is a mixture of health reasons and operational limitations.
    – Narusan
    Sep 13, 2018 at 0:17
  • Yeah, the health reasons seem mostly involved with other uses for water though (like bathing, i.e. the eyes). Just wanted to emphasize the contrast with OP's poorly supported hypotheses about pH changes with age and some notion of balance. There's certainly nothing wrong with drinking water below pH 4 assuming the pH is from something safe like carbonic acid - that's just soda water that people drink all the time, and that's outside the ranges you mention. But you wouldn't want to put soda water through a municipal water supply.
    – Bryan Krause
    Sep 13, 2018 at 0:38

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