The sale of alkaline water is nothing new and started several years ago in the USA, where it is supported by really massive advertising, including famous celebrities such as Beyonce or Tom Brady and of course many nutrition "gurus". According to data from a report from Zenith Global, the global alkaline water market is rocketing - valued at $631 million in 2017 and this is set to continue to soar.
Let’s talk about what alkaline water is.
Compared to tap water, alkaline or basic water contains a higher amount of minerals such as calcium, magnesium, potassium or bicarbonate (baking soda), which can account for its higher pH (usually 8-10) and therefore its "alkalinity". Whereas "normal" tap water has a neutral or "only" slightly alkaline pH. Minerals are added artificially to this alkaline water or are already naturally present. Other methods of production include ionisation, but the ions in the water tend to neutralise each other, so that after a while the pH of such water will level off back to its original value.
The whole theory about the effect of alkaline water is based on the claim that thanks to the Western type of diet our body is constantly "over-acidified" (so-called chronic low-grade acidosis) and this chronic acidosis, according to its promoters, leads to basically every disease you can think of - from cancer to problems with sweating. This concept of a single cause for almost all ailments is typical of most con artists and charlatans, who can offer a simple, one-size-fits-all solution to virtually all your problems. Check out the false advertising claims from a prestigious food shopping website:
❌ "Drinking alkaline water for prophylaxis will stop acidification of the body, normalize the pH of the blood, maintain the right amount of alkaline buffers and help your body remove the accumulated acidic waste of several years. This means rejuvenation of the body's tissues and internal organs."
What's it really like? The acid-base balance in our bodies is very strictly maintained by complex systems of buffers and organs such as our kidneys and lungs. This is because our body and enzymes can only function properly at an optimal blood pH of 7.36 - 7.44. A slightest deviation from this range leads to very serious conditions that directly threaten the life of the person concerned - this is called metabolic or respiratory alkalosis or acidosis. However, these conditions occur only in severe diseases such as decompensated diabetes or problems with the kidneys or respiratory system. If you deviate from the physiological pH range, you will definitely know it!
THE PH OF OUR BLOOD CANNOT NORMALLY BE INFLUENCED IN ANY WAY BY DIET OR DRINK.
If this were the case, even orange juice, which has a pH value of around 3.5, would be harmful to us. However, our body can cope very well with drinking an acidic drink with a low pH. This is because our acid-base balance is actually one of the most tightly controlled systems in our body - if it wasn't, we wouldn't survive!
So we cannot affect the pH of our blood with food or drink, but it is only possible to change the pH of our saliva or urine. However, proponents of this "acidification" theory often argue that it is only a small change in pH at the limit of the physiological range, but that it is more difficult for the body to maintain it within this optimal range and thus places a greater burden on the body. Some also argue for overacidity at the level of individual cells or organ systems, but this cannot usually be measured (unexpectedly), and some organs are even naturally "acidic" themselves (e.g. the stomach with a pH of 2-4). They also often refer to or directly rely on a 1995 study on the so-called PRAL score of common foods, the results of which they purposely misinterpret (misinterpretation of scientific studies is another hallmark of quacks).
The above-mentioned 1995 study by Remer and colleagues looked at the so-called PRAL score (potential renal acid load) for commonly consumed foods.
However, this score is not related to the pH value of the food, but rather to its ability to form acids or bases in the body - for example, orange juice, despite its acidic pH, has a PRAL score of -2.9, and a negative PRAL score means that the food is alkaline or, more precisely, forms more alkaline substances in the body. However, it must be stressed that the PRAL score is not related to the pH value of our cells or blood, but primarily affects the pH of our urine. In fact, the authors of this study were not looking for a cure for acidity (!!!), but the purpose of this study was to investigate the possibility of preventing urinary stones (called urolithiasis) by influencing the pH of the urine through diet. Other diseases that we can potentially influence by this mechanism include urinary infections.
WHAT DOES CURRENT SCIENTIFIC KNOWLEDGE HAVE TO SAY ABOUT ALKALINE WATER?
A recent 2016 systematic review from the British Medical Journal on the link between alkaline water and cancer treatment claims, "Despite the promotion of alkaline diets and alkaline water by the media and retailers, we have almost no evidence to support or refute these claims. This systematic literature review lacks evidence for or against the use of alkaline water for cancer treatment. Promotion of alkaline diet or water for cancer prevention or treatment is not justified."
A 2011 systematic review said, "The causal relationship between dietary intake of acidic foods and osteoporosis is not supported by scientific evidence, nor is there evidence of a protective effect of an alkaline diet."
Conclusion
The current scientific knowledge in no way supports the exaggerated claims and health benefits presented by the sellers of alkaline water or the celebrities who are very well paid by these companies. Claims of normalizing blood pH and eliminating "several years of acidic waste" are flat out lies. Alkaline water is also usually many times more expensive compared to tap or even 'ordinary' bottled water and often has a higher ecological footprint due to its importation. Alkaline water, according to current scientific evidence, differs from 'ordinary' tap water only in the content of some minerals, which can have a positive effect in people with mineral deficiencies, but there are certainly many cheaper ways to supplement these minerals. According to some sources, alkaline water may have a higher hydration capacity due to its mineral content or may help people who suffer from reflux, but more studies on this topic are still needed. Conversely, people with kidney disease should be careful due to the increased mineral content. So, if you have access to clean, high quality water that flows from your tap for a few pennies, consider yourself lucky, because not everyone has this option, and don't try to improve water, which is the carrier of life and has miraculous effects in itself, even without a little added minerals or exotic origin, and without having to pay hundreds of crowns for a few litres.
Literature
REMER, Thomas; MANZ, Friedrich. Potential renal acid load of foods and its influence on urine pH. Journal of the American Dietetic Association, 1995, 95.7: 791-797.
FENTON, Tanis R.; HUANG, Tian. Systematic review of the association between dietary acid load, alkaline water and cancer. BMJ open, 2016, 6.6: e010438.
FENTON, Tanis R., et al. Causal assessment of dietary acid load and bone disease: a systematic review & meta-analysis applying Hill’s epidemiologic criteria for causality. Nutrition journal, 2011, 10.1: 41.
FENTON, Tanis R., et al. Meta‐analysis of the effect of the acid‐ash hypothesis of osteoporosis on calcium balance. Journal of Bone and Mineral Research, 2009, 24.11: 1835-1840.
KOUFMAN, Jamie A.; JOHNSTON, Nikki. Potential benefits of pH 8.8 alkaline drinking water as an adjunct in the treatment of reflux disease. Annals of Otology, Rhinology & Laryngology, 2012, 121.7: 431-434.
WANG, G.; ZHU, P.; WANG, S. The causes, diagnosis and treatment of aluminum toxicity in patients with chronic renal failure undergoing dialysis. Zhonghua nei ke za zhi, 1996, 35.1: 36-40.
REFFITT, David M., et al. Silicic acid: its gastrointestinal uptake and urinary excretion in man and effects on aluminium excretion. Journal of Inorganic Biochemistry, 1999, 76.2: 141-147.
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