Do you also drink “magic water” every morning to maintain your body’s pH balance? That’s exactly how self-proclaimed health experts now recommend everyone start their mornings. They promise that an alkaline diet will eliminate all inflammation from your body and make you the healthiest person in the world. Some even claim that it can help you overcome a cancer diagnosis.
Let’s take a closer look at what an alkaline diet actually entails.
Alkaline nutrition is a trend that has regained popularity; it claims that people should maintain a balanced pH level in their bodies through diet. Specifically, it claims that excessive acidity in the body causes inflammation, accelerates the aging process, and creates a favorable environment for the development of cancer cells.
To correct this, one should eat alkaline foods to keep the body’s pH in balance. One news platform, for example, states that cheese, milk, salt, meat, and grains promote blood acidity. At the same time, however, consuming apple cider vinegar and lemon juice has an alkalizing effect on the body.
What does the body’s pH actually mean?
pH indicates the acidity or alkalinity of a solution. The more free hydrogen ions there are, the more acidic the environment and the lower the pH.
The body is not one large, uniform fluid compartment. It consists of many separate compartments, and each has its own pH, which the body regulates according to the compartment’s function.
For example, the stomach must be very acidic. The pH of stomach contents can range from approximately 1 to 3. This acidity is necessary for digesting proteins, activating pepsin, and destroying many microorganisms found in food. Therefore, it cannot be said that an acidic environment is always bad for the body.
“Body pH” is not a single, precisely defined measurable parameter. Different parts of the body are supposed to have different pH levels: the stomach is very acidic, blood is slightly alkaline, and urine pH can fluctuate significantly.
When doctors talk about acid-base balance, they are usually referring primarily to blood pH. The normal pH of blood is approximately 7.35–7.45, so blood is naturally slightly alkaline.
The body maintains blood pH within a very narrow range because proteins, enzymes, cell membranes, the nervous system, and heart function all depend on the correct pH.
What happens if the blood’s pH falls outside this range?
If the blood’s pH falls outside this range, the functioning of nearly all proteins, enzymes, ion channels, and cells is disrupted. The pH scale is logarithmic; thus, a change from 7.4 to 7.1 may seem small, but in reality, the concentration of hydrogen ions has approximately doubled.
Minor deviations may not necessarily cause symptoms on their own. The following signs are primarily characteristic of pronounced or rapidly developing acid-base imbalances.
If the blood becomes too acidic:
A person begins to breathe faster and more deeply.
Heart function may weaken.
Blood pressure may drop.
If the blood becomes too alkaline:
The amount of ionized calcium decreases.
Muscle cramps and twitching occur.
Possible heart rhythm disturbances.
This shows that blood pH is not something that should be pushed toward the more alkaline side. It is more like body temperature, which has a narrow normal range, and deviations in either direction are harmful.
How are foods classified as alkaline?
In the world of alkaline diets, the term PRAL—or potential renal acid load—is most commonly used. This measures how much acidic or alkaline waste the kidneys must eliminate in the urine after metabolizing food. It primarily takes into account a food’s protein, phosphorus, potassium, magnesium, and calcium content. However, this system was developed to assess renal acid load and urinary pH, not for the body as a whole.
Thus, fruits, vegetables, and some legumes are typically classified as “alkaline.” For example, the body can convert citrate found in fruits into hydrogen carbonate, which means the kidneys have to excrete less acid and the urine may become more alkaline.
Meat, fish, eggs, cheese, and grains are often referred to as “acidic” because certain amino acids in proteins can produce sulfates and phosphates during metabolism, and removing these places a burden on the kidneys.
This means that alkaline foods are not chemically alkaline, but are classified into this group based on their PRAL.
Scientific studies use PRAL, among other measures, to assess the potential acid load of foods, but lists of alkaline and acidic foods circulating online may not consistently follow this system.
What does an alkaline diet actually affect?
In a healthy person, a normal diet does not significantly alter blood pH, as the lungs, kidneys, and buffer systems keep it stable. The acid load from food can become more significant, for example, in cases of kidney disease, when the kidneys are no longer able to remove acids effectively enough.
Such a diet most noticeably affects urine pH, as the kidneys must remove acidic and alkaline compounds produced during metabolism from the body.
Food can also temporarily affect the pH of the mouth, stomach, and intestines, but these changes are usually localized and temporary. A change in the pH of the mouth or stomach does not mean that the blood pH has changed at the same time.
What can affect urine pH?
Urine pH affects how well various substances dissolve in the urine. For this reason, urine pH is important, for example, in the context of kidney stones. Acidic urine can promote the formation of uric acid stones, while urine that is too alkaline can promote the formation of calcium phosphate stones.
Thus, urine pH has an important physiological effect, but its impact is primarily limited to the kidneys and urinary tract. More alkaline urine does not indicate better health and does not reflect the pH of the blood or other tissues.
Alkaline Diet and Inflammation
An alkaline diet typically includes more fruits, vegetables, legumes, and other unprocessed plant-based foods. At the same time, it is recommended to reduce the consumption of added sugars, alcohol, highly processed foods, and processed meats. Such a change can indeed improve health and reduce certain markers associated with chronic inflammation.
However, the reason is not that the body becomes more alkaline. The benefits may stem from increased intake of fiber, vitamins, and plant-based bioactive compounds, changes in the gut microbiome, or weight loss.
Furthermore, no single diet can eliminate all inflammation from the body. Inflammation is a normal response of the immune system, and there can be many different causes for it to persist chronically.
How is an alkaline diet supposed to treat cancer?
The claim that an alkaline diet can treat cancer is based on the observation that the environment surrounding a tumor may be more acidic. From this, the erroneous conclusion is drawn that acidic foods created this environment and that alkaline foods could neutralize it. In reality, the more acidic environment is caused by the tumor’s own altered metabolism and inadequate blood supply.
Making urine more alkaline does not make the area surrounding the tumor more alkaline. Nor can the pH of the blood be raised through diet to a level that would destroy cancer cells.
Some observational studies have linked a higher dietary acid load to an increased risk of cancer, but this does not prove that the cause is acidity in the blood or the “body.” There is no clinical evidence that an alkaline diet treats existing cancer.
Possible exception: chronic kidney disease
In a healthy person, the kidneys are able to remove acid produced by a normal diet. In chronic kidney disease, the kidneys’ ability to excrete acids and produce bicarbonate may be reduced. As a result, a person may develop metabolic acidosis, which is assessed based on blood bicarbonate levels.
A diet with a lower acid load—such as a plant-based diet—may help control acidosis in selected patients, but it is not a general “alkaline diet” or a treatment for kidney disease as a whole.
In summary: a healthy diet, but based on false premises
The alkaline diet is more of a passing trend associated with treatment claims that lack scientific basis. There is no scientific evidence that a person can use food to make their entire body’s pH more alkaline in any way and thereby reduce inflammation, slow down aging, or cure cancer.
The benefits of the diet are much easier to explain. If a person starts eating more fruits and vegetables and less added sugar, alcohol, and highly processed foods, their health may indeed improve. This is due to the person’s new, nutrient-rich diet.
The alkaline diet is a good example of how misleading explanations can be attached to sensible dietary recommendations. That’s why it’s important to evaluate not only which foods are recommended, but also the evidence used to justify the claimed health benefits.
How can we distinguish science from marketing?
You should be especially cautious about any dietary advice if the advisor:
claims that a single diet can treat several different diseases
recommends discontinuing treatment prescribed by a doctor
makes treatment claims without reliable research
sells dietary supplements as a solution
dismisses criticism as propaganda from the pharmaceutical industry
does not disclose their education or professional qualifications
A healthy person may change their diet based on how they feel, their goals, or their preferences, but in the case of illness, dietary treatment should be based on a diagnosis and test results and should be planned in consultation with a specialist who has received the appropriate training.
When you see a new diet trend, ask:
Are the claims backed by high-quality human studies?
Does the advisor stand to gain anything from promoting this “miracle solution”?
Healthy eating doesn’t need a fancy name or a made-up pseudoscientific explanation to work. The alkaline diet’s recommendation to eat more fresh fruits and vegetables may be beneficial, but not because they make the body more alkaline. So, it’s worth keeping these healthy food choices on your menu, but take a critical look at the misleading health claims made about them.
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