Carbonic acid, for example in mineral water, is acidic, as its name suggests. Is carbon dioxide in drinks therefore harmful or relatively unproblematic? Can you drink sparkling water or is still water better?
Can carbonic acid in drinks harm your health?
One might think that carbonic acid is an acid, so it should irritate the acid-base balance and contribute to hyperacidity. So is it true that carbon dioxide in drinks is harmful? Or is it safe to drink carbonated beverages? Could carbonation even have health benefits?
How carbonic acid changes the pH of the water
The carbonic acid is undoubtedly acidic because while still mineral water usually has a more neutral pH value (around 7), sparkling mineral water has a lower (i.e. acidic) pH value (between 5 and 6.5). Below are four examples:
- Perrier (pH 5.5)
- San Pellegrino (pH 6)
- Gerolsteiner (pH 5.9 to 6.7)
- Christine fountain (pH 6)
With Selters mineral water you can see how the carbonic acid lowers the pH value, because Selters Naturell (non-carbonated) has a pH value of 7.33, while Selters Classic and Selters Medium have a pH of 5.7 to 6, 3.
Is Carbonated Water Natural?
Some people may think that it can’t be healthy to drink acidic water all the time, after all, you should keep an eye on the acid-base balance and therefore better pay attention to a basic or base-excessive diet.
Also, carbonated mineral waters are anything but natural, one might think, since there are no soda makers to be found in fields and forests. Most springs are actually non-carbonated, but there is at least slightly carbonated water in nature, for example in volcanic regions such as the Eifel (Gerolsteiner). Such water is not that unnatural.
The usual arguments against carbonated drinks
But what are the health effects of drinking carbonated mineral water? Most often, the following anti-arguments are listed:
- Carbonated acid or beverages containing it are said to be acidic and especially harmful to the stomach and esophagus.
- Carbonated acid or beverages containing it are said to damage tooth enamel.
- Carbonic acid is supposed to pull calcium out of the bones, i.e. reduce bone density.
- Carbonated drinks are also said to make you fat.
Before we get into each point, first of all, what is carbonic acid and how does it get into the water and other beverages?
What is carbon dioxide and how does it get into drinks?
Carbonic acid is a reaction product of carbon dioxide (CO 2) and water, so if carbon dioxide is introduced into water under pressure, carbonic acid is formed there.
It was Jacob Schweppe who, at the end of the 18th century (around 1780), first developed a process with which water could be carbonated, or actually carbon dioxide. Initially, this was only intended for medicinal purposes. However, since his product (today’s Schweppes) became a real hit, he and two partners founded a soda water factory in 1790.
In the natural process, carbonic acid is also formed in regions with volcanic activity. As the magma cools, the carbon dioxide is released deep into the earth and combines with the mineral water there. Example: Gerolsteiner from Gerolstein in the Vulkaneifel.
Does carbonated mineral water make you sour?
Although fizzy drinks are definitely acidic, they don’t make you acidic in the long run. Because the carbon dioxide it contains is quite unstable and quickly breaks down into its components CO 2 and water. Everyone knows it: You open the bottle and the carbonic acid escapes with a hiss (in the form of CO 2). The rest breaks down in the stomach, causing you to belch.
The body, therefore, does not even absorb carbonic acid. So there is no need to fear over-acidification. This is indirectly caused by the hydrochloric acid in the stomach. This has a pH value of 1.5 to 2. If the carbonic acid or the carbonated mineral water is added, which has a significantly higher pH value, the overall pH value in the stomach even increases.
Carbonic acid for a sensitive stomach
However, there are people who react to fizzy drinks with stomach problems, most people who already suffer from an upset stomach with occasional heartburn. However, they do not react to the carbon dioxide in the soda, but to the bubbles of CO 2, which can irritate the esophagus and stomach.
In addition, any belching causes gastric juice to travel towards the esophagus, so the carbon dioxide promotes heartburn in sensitive people. These people should actually then drink still water. If you also make sure that you drink water with a high bicarbonate content, this will neutralize excess acids, including those that are produced during normal metabolism.
But beware: water with a very high hydrogen carbonate content is often also rich in sodium, which can increase the body’s salt load, which is particularly the case with the so-called medicinal springs. Here are three examples for a small overview (mg per liter):
- Source of Adelheid: 2937 mg bicarbonate and 966 mg sodium
- Gerolsteiner natural: 577 mg hydrogen carbonate and 17 mg sodium
- Volvic: 74 mg bicarbonate and 12 mg sodium
So don’t just look for a high hydrogen carbonate content, it is better to choose a medium one (e.g. Gerolsteiner natural) and low sodium content. Here you will find a table with 100 mineral glasses of water for comparing the mineral content and you can select the one that is suitable for you. So you don’t have to buy Gerolsteiner mineral water just because we often mention it as an example. It’s not advertising like we’ve been accused of. The Gerolsteiner company knows nothing about this article!
How carbonic acid in water could even benefit the stomach
For heartburn and reflux, fizzy drinks are generally discouraged as they provide acids and carbon dioxide, both of which could make acid reflux worse – it was always thought, given that some people actually did.
However, an Italian double-blind study from 2002 showed that sparkling water can actually be helpful for irritable stomachs and constipation. The 21 participants suffered from dyspepsia (upset stomach) and constipation. 10 participants drank carbonated water for almost two weeks, and the control group of 11 subjects drank tap water.
In the carbonic acid group, the stomach problems improved significantly, in the tap water group everything stayed the same. The carbon dioxide also improved the emptying of the gallbladder, which promoted digestion and thus counteracted constipation.
Of course, the number of participants in this study, at 21, was small. However, in February 2010 a review (analysis of the studies that have been published on this subject) revealed that carbonated water had no negative effects on reflux disease. It can neither cause nor worsen reflux.
Although the intake of carbonated drinks is said to initially cause the pH value in the esophagus to drop, this is only the case for a very short time, so – according to the researchers involved – there is a risk of direct damage to the esophagus or even an increased risk of esophageal cancer. no indications so far.
Carbonation for constipation
For constipation, carbonated water may be more advisable than still water, especially for people with severe disabilities, a 2011 study found. Forty elderly patients who were bedridden after a stroke and therefore constipated were given either sparkling (carbonated) water or still water.
In the carbonic acid group, the frequency of bowel movements increased significantly, which significantly improved constipation. No change was noted in the tap water group; the constipation was more likely to persist here.
Can carbon dioxide damage teeth?
Most of the studies on this subject have been conducted by placing extracted teeth in various liquids, so the results do not always translate to the living tooth in humans, who also do not keep their drinks in their mouths for minutes.
In a 2001 study, for example, extracted teeth were placed in various types of mineral water. But even here little or no damage to the teeth could be observed.
The small risk of damage was there, but not at all with still water. In the case of carbonated soft drinks, the damage potential was – not surprisingly – a hundred times higher than that of carbonated mineral water.
In particular, the minerals in the mineral water (calcium and magnesium) protect the tooth enamel from dissolving, according to the study mentioned, so that in mineral-rich, carbonated water, the minerals can compensate for a possible harmful effect of the carbon dioxide.
This effect no longer applies to flavored water, as this usually contains sugar and citric acid, both of which are known to be highly damaging to teeth. Citric acid is not only harmful because of its acidic character, but also because it can also bind calcium, which is then lost from the tooth.
Therefore, a study from 2007 showed that the negative impact of flavored water was comparable to that of pure orange juice (which is known to be harmful to teeth), in some cases even stronger, which was due to the fact that the lemonades had a very low-level thanks to the addition of citric acid pH (2.74-3.34).
However, another Swedish study from 2004 states that whether carbonated drinks damage your teeth depends not only on their ingredients but also on how you drink the drink. The longer the drink is kept in the mouth, the more harmful it is to the teeth. According to this study, it is therefore ideal for the teeth if you swallow drinks with a low pH value as quickly as possible.
In the case of carbonated water, however, we (ZDG editors) would not advise pouring it down too quickly. Drinking slowly, like eating slowly, is always advisable.
Carbonated drinks, which are considered to be clearly harmful to teeth, such as sweetened soft drinks, flavored mineral water, or juice spritzers, should of course not be kept in the mouth for minutes or, in the case of sweetened drinks containing citric acid, not even consumed.
Does carbonic acid damage bones?
According to a study from 2006, carbonic acid also has no negative effects on bone density. In the course of the Framingham osteoporosis study, the bone mineral density of the spine and hip bones was measured in 1413 women and 1125 men. Of course, other factors such as BMI, size, age, energy intake, physical activity, smoking, alcohol consumption, and intake of calcium, vitamin C, and caffeine, and, in women, menopausal status and possible estrogen use were also taken into account.
While cola had a significantly negative effect on bone density in women (not in men), consumption of other carbonated beverages had no negative effects on bone density. The women who drank cola regularly had a 3.7 to 5.4 percent lower bone density than those who rarely or never drank the drink. It was almost irrelevant whether it was regular cola, diet cola, or caffeine-free cola.
A year earlier, another study on this subject found that carbonated mineral water had no negative effects on bone health. In this study, healthy postmenopausal women drank 1 liter of carbonated mineral water daily for 8 weeks.
Yes, carbonic acid in the water could actually improve bone health, which was found in laying hens in the USA in the 1990s. At that time, the animals had been given carbonated water instead of normal tap water, which after 6 weeks led to better protection against broken bones.
Does Carbonated Water Make You Fat?
Fizzy water may promote weight gain, according to a 2017 study. Researchers observed that rats given fizzy drinks gained weight faster than rats given the same non-fizzy drinks. Apparently, the carbonic acid raised the ghrelin level. Ghrelin is an appetite-stimulating hormone.
The result was confirmed by a similar test on 20 men. An increase in ghrelin after consumption of carbonated drinks was also observed in these subjects.
Five years earlier, a Japanese study of women found the opposite: 19 healthy young women first fasted overnight and then slowly drank either still or carbonated water.
The women who drank the sparkling water felt satiated without feeling uncomfortable. The gas in the water caused the stomach to expand slightly, increasing the feeling of satiety, which was not the case to the same extent in the still water group.
Observe yourself how you react to carbonated mineral water, whether you have more or less appetite afterward, and change your drinking behavior or your choice of mineral water accordingly.
Summary: So are carbonated beverages harmful or beneficial?
Overall, the studies available to date have tended to show that carbonated water obviously does not harm health and in some cases even has health benefits. Here again, is an overview of the frequently put forward anti-arguments and how it behaves according to the current study situation:
- Carbonated or carbonated beverages are said to be acidic and especially harmful to the stomach and/or the esophagus.
Carbonation can irritate the stomach and increase heartburn in some people, in others it has no effect on the stomach, and in others, it may even improve an upset stomach. Here it is important to observe yourself and test which water is more suitable – with or without carbonic acid.
- Carbonated or carbonated beverages are said to damage tooth enamel.
This has not been shown in reality. Sugary drinks and lemonades that contain citric and/or phosphoric acid are harmful to teeth. If, on the other hand, it is only carbonated mineral water, this does not harm the teeth.
- Carbonic acid is said to pull calcium out of the bones.
That’s not true either, as it’s more likely other acids found in carbonated sodas that could damage bones, such as citric and phosphoric acids. However, the carbonic acid in water has no negative effects on bone health.
- Fizzy drinks are said to make you fat.
There are inconsistent study results on this. In general, if the water is carbonated, it may be more likely to help you lose weight because it increases the feeling of fullness. Carbonated soft drinks, on the other hand, seem to activate the hunger hormone ghrelin and therefore encourage people to eat more.
Conclusion: Should you drink sparkling or still water?
Choose the water – sparkling or still – that is good for you personally. If it’s still water and you’re fine with it, perfect, stick with it. There is no need to switch to carbonated water.
If you prefer drinking carbonated water and you’re fine with it, there’s no reason to stop drinking that either. However, if you suffer from stomach problems after drinking sparkling water, try still water.
In the case of diarrhea, it has been shown that carbonic acid could make it worse, so in this case, it is better to switch to still water or teas that soothe the intestines.
However, carbonated soft drinks should be avoided at all costs, not so much because of the carbon dioxide, but because of the other acids they contain, the sweeteners, and possibly other additives.