Alkaline or ionized water was all the rage some years back in the domestic water category. It hasn't lost it shine though. New and supposedly ever better models are still coming out and sales staff are still fervently promoting the benefits of drinking alkaline water.
In fact, in c2011, I was approached by one company to write a book on the health benefits of alkaline water. Being somewhat skeptical then (and even more skeptical now), I respectfully decline.
Then in c2013, another company approached me to conduct experiments to help substantiate the claims of its ionized water. This time, instead of talking about drinking the water itself, the company is interested in promoting the use of ionized water to preserve food, cooking and preparing beverages. It was convinced that food and beverages prepared as such were fresher, better tasting while retaining the benefits of drinking alkaline water. In this case, I must admit that the request was kind of outside my expertise so I happily pass it along to my food colleagues.
(It should come as no surprise that alkaline water can preserve food well because of its high pH which makes the environment hostile to most microbes, especially if the food is dipped in a large vat of alkaline water.)
So how is alkaline water produced anyway?
It is typically produced in a machine commercially named a water ionizer. One part of the resultant water has above neutral pH (alkaline) of 8-11. (FYI, the pH scale ranges from 0 (highly acidic) to 14 (alkaline).) You can actually make alkaline water yourself (DIY) by adding sodium bicarbonate (just a fanciful chemical name for baking soda) into your water. But since the profit margins for selling baking soda are simply too low compared to selling a shiny and sophisticated machine like a water ionizer, no self respecting company will want to mention the possibility of DIY to make alkaline water.
[Start of tech talk]
Back to the water ionizer... it makes use of electrolysis - passing an electrical current through water between 2 electrodes - 1 positively charged, 1 negatively charged. In simple terms, positively charged ions (cations) like calcium and magnesium migrate to the negatively charged electrode (cathode) while negatively charged ions (anions) like sulfate and chloride migrate to the positively charged electrode (anode). The cathodic region becomes alkaline due to reactions between the cations and water and no surprise, the anodic region becomes acidic due to reactions between anions and water.
To further prevent the cations and anions from coming together again, ion selective membranes (a really thin film with special properties) separate the cathodic and anodic regions, allowing ions to pass only in 1 direction. In proper technical speak, the whole process should be called electrodialysis (because of the membrane) rather than electrolysis but I suppose electrolysis sounds easier to digest for most sales people and customers.
[End of tech talk for now]
Lots of water ionisers come with filters and other water treatment accessories e.g. activated carbon. To me, they complicate the issues regarding alkaline water. If you become healthier after drinking alkaline water, is it because of the alkalinity itself or is it because the water is cleaner after filtration? Nevertheless, I will focus on alkaline water per se in this post. You can find out more about water filters in my other posts.
How does alkaline water benefit you?
If you read up on the advertised claims of the suppliers, alkaline water can:
- delay ageing
- counteract cancer
- lower blood cholesterol, sugar and pressure
- remove stones
- prevent arthritis
- weight loss
- improve energy levels
- keep heart, liver, bones healthy
- probably improve lots of other health issues you can think of
Naturally, I am skeptical when a commercial product or service comes with more beneficial claims than snake oil. After all, how do you effectively prove so many claims. It is not easy to do scientifically robust studies to prove a single health claim. You need time to do that. For example, drugs can take years or more before they are allowed to be sold on the market. The gold standard will be clinical studies of patients involving double blind experiments. You don't see that with alkaline water (and lots of other health supplements). Yes, I know drugs are different from alkaline water but the health claims are no less serious and in many cases, alkaline water sounds more omnipotent than any drug.
And in some cases, the suppliers use BIG words like "miracle" water. This really sets off the BIG warning alarms in my head and have me recoiling with BIG question marks.
Eventually, what you often see are "testimonials" from "satisfied" customers. "After drinking alkaline water form XYZ brand, I feel healthier... I no longer suffer from health problem ABC... At first, I am unsure but after trying it out, I am a true believer." I bet you see roughly the same testimonials as above more often than you care to count. In a way, they are selling hope but what you don't want is when hope and reality don't meet.
By now, I can hear some of you asking what does WHO say about pH in its drinking water guidelines. Well, in WHO 2011 edition, there is no recommendation for pH as it is not a health concern though Singapore's Environmental Public Health (EPH) regulations stipulate a pH of 6.5-9.5. I believe this range is more for protection of piping and equipment against corrosion in too acidic or alkaline an environment.
The Science behind the scenes
Sometimes, scientific theories are presented out of context. Yes, acid and alkali neutralise each other. So if you body is too acidic (bad for health), simply drink some alkaline water to achieve balance again. Simple, right?
If you believe that, maybe you also believe that you can remove your brain from you body and hook it up with wires and electrodes in a nutrient vat so that you can live beyond the demise of your body. (Just kidding) Unfortunately, our bodies are really complex machines. What works in a vat usually does not work in the real body with its many biochemical/biomechanical operations interacting in ways many times as yet not understood.
Take pH for example. Human blood pH is an average of 7.4 (slightly above the neutral of 7). Drop below 7.35, you get acidosis. Go above 7.45, you get alkalosis. Both conditions can lead to serious health complications. The reason why human (and animal) blood needs to maintain such a stable pH is because pH is often quoted as the master parameter in any system, be it human body or a pond. It affects how chemical and biochemical reactions will play out. A different environmental pH will lead to a different reaction pathway, giving rise to different products. Or the reaction may not even proceed at all.
So why are people talking about the body being too acidic? The body will automatically correct the blood pH within the narrow range of 7.35-7.45. (WE are talking about blood pH here. Saliva and urine will have a slightly different pH range. Stomach pH IS acidic - see below. Healthy fetal blood pH is also slightly different.) How in the world is alkaline water helpful?
For those who remember your biology, stomach pH is acidic, say 1.5-3.5. You need this level of acidity to properly digest your food and to kill off many pathogens. (IN chemical terms, the acid is to break up the chemical structures of foodstuff like proteins so that your digestion enzymes can do their work on the fragments.)
IN case you are worried that drinking alkaline water will neutralize this acidity, good news - a healthy stomach can automatically compensate for such actions and retain it normal pH range. So my point is - when you drink alkaline water, it ends up mostly in your stomach where it is neutralized by your stomach acids. How are its benefits supposed to be transferred to your body??? (FYI, once your acidic stomach contents reach the small intestine, bicarbonate is secreted to neutralize the acids so that the acidity does not travel further down your system.)
Lastly, if anyone reading this feels strongly about alkaline water being really vital for health, please do not flame me and just go ahead to drink it if it makes you feel better. This is after all a free society. As for me, I will keep alkaline water at a distance. More often than not, we just need an adequate dose of good old plain water to function efficiently at optimum health. Keep this a priority before you open your wallet to other "healthy" options.