Diet & Weight loss

The truth about the alkaline diet with acid-base balance

Acid-Alkaline-Plate

You’ve probably heard of some celebrities who follow the alkaline diet , a diet whose goal is to change the alkalinity of blood to be healthier. To tell you the color of this article, know that one of the gurus of this scheme, Robert Oldham Young, is currently in prison for posing as a doctor when he had no degree.

How did all this begin? In his book “The pH Miracle”, he details his belief that acidity in the blood (acidosis) causes disease.

His theory: “By making the body more alkaline (by eating certain foods), you can reduce disease, lose weight, have more energy, strengthen your immune system, improve digestion and sleep.”

But if this person had really gone to medical school, she would have known that the pH of the blood does not vary, that we eat acidic or basic foods. The only thing that changes is the acidity of the urine.

The idea that blood pH is out of balance with our way of life is just an “idea”. And it’s an idea that has been repeated so many times, with such conviction, that people began to believe that it was true.

The main evangelists of this regime are the Hollywood stars, whom millions of people follow naively. And one of the most well-known fans of this wacky food fad is none other than Gwyneth Paltrow. To give you an idea of ​​the level, this actress recently recommended that women insert jade eggs into their vaginas, to increase their sexual pleasure among other more or less medical benefits …

Despite a great deal of scientific evidence that the alkaline diet does not bring any benefit, the alkaline diet continues to persist in some people’s minds. Here is all you need to know about this famous acid-base diet.

A little reminder of the acid-base balance

acidic-alkaline-phchart

If you do not remember your high school chemistry class, the pH, for potential Hydrogen, can measure the acidic or basic character of an aqueous solution. The pH scale is graduated from 0 to 14, and 0 to 6.9 is acidic, 7 is neutral, and all that follows (up to 14) is basic. Basic and alkaline are synonymous.

  • The pH of the blood of a healthy human being is a little alkaline: 7.4.
  • The pH of stomach acid is naturally much lower, usually 3.5 or less.

To classify alkalizing and acidifying foods, the PRAL (Potential Renal Acid Load) index is used.This index characterizes the effect of the foods consumed on the renal acid load potential, aka the degree of acidity of the pee.


Foods that have a negative PRAL score are considered alkaline. This includes lemons and most other fruits and vegetables. Foods with a positive score are considered acidic or acidifying. It includes cereals (oatmeal, rice), animal protein (meat, fish) and dairy products.

To return to lemons, they are acidic fruits with a pH of 2. But they are broken down by our body into an alkaline substance that helps to lower the pH of the urine. This is the reason why they are classified in the family of alkalizing foods.

Diet and body pH

Eating different foods on the PRAL index can change the urinary pH, but the pH of the urine changes quickly and easily, and is influenced by many factors, so physical activity. And we’re not going to stop training to have less acidic urine …

On the other hand, some foods may also have a different impact on urine pH when combined with other foods, making the PRAL index irrelevant.

The central claim of the alkaline diet, saying that acidic foods have a negative impact on blood pH does not hold for one reason: the food we eat does not alter the pH balance of our blood . The pH of the blood is tightly regulated by the lungs and kidneys.

I think you’re starting to understand, that this diet is a pretty trick, very effective at selling all kinds of books, nutrition programs, alkalizing products and supplements, and so on.


In fact, it’s like going back several years and being told: “Do not eat too much egg yolks because they’re cholesterol-laden, it’s very bad for your health. ! ”


I hope you did not think that … eating egg yolks raised cholesterol levels …

It’s been a long time since science has shown that dietary cholesterol has very little impact on blood cholesterol levels.

For the acidity of food is the same, the impact is ridiculous and there is no need to break the head to look for alkaline food, limit or remove the meat, this or that food family (except if you have renal or pulmonary insufficiency).

That said, just because some people are intolerant to gluten does not mean that everyone should not eat it anymore.


Variety is the key to a good diet!


Acidifying foods do not cause osteoporosis

alkaline diet

Osteoporosis is a progressive bone disease characterized by a decrease in the mineral content of the bone.

This disease is particularly common in postmenopausal women, and can dramatically increase the risk of fractures.

Many lovers of the alkaline diet think that to maintain a constant blood pH, the body uses alkaline minerals (such as calcium) bones to buffer the acids from the acidifying foods you eat.

According to this theory, our western diet would be the cause of a loss of bone mineral density.

The problem with this theory is that the function of the kidneys is completely ignored. If you do not know yet, one of the main functions of the kidneys and to filter the blood, and especially to eliminate the acids to regulate the pH of the body.

The kidneys produce bicarbonate ions that neutralize acids in the blood, an effective process that allows the body to tightly regulate blood pH. Here is a little physiology class if your heart tells you.

Our respiratory system is also very involved in the control of blood pH. When bicarbonate ions of the kidneys bind to acids, they are carbon dioxide (which we exhale) and water (which we pee).

Bones are not involved at all in this process.

Another problem with the hypothesis that acidic foods cause osteoporosis is that it ignores one of the main drivers of osteoporosis: a loss of bone collagen protein  .

Ironically, this loss of collagen is strongly related to low levels of orthosilicic acid and ascorbic acid (vitamin C) in the diet.

Looking at the research, zero observational studies have never shown a relationship between food acid and bone density or risk of fracture. Indeed, there is not even a relationship between the pH of urine and bone health  .


Contrary to popular belief, diets high in protein (acid generator) are actually linked with healthier bones  .


Looking at clinical trials (true science), many large studies have found that acidifying diets have no effect on the body’s calcium levels .

On the contrary, they improve bone health by increasing calcium retention and activating IGF-1, a hormone that stimulates muscle and bone repair  .

Merits not to be denied

It must be recognized, it is still a good thing to promote the consumption of fruits and vegetables.

Indeed, not to mention acid-base, they provide vitamins, minerals, dietary fiber, etc. That’s why, in a sense, this fashion is not that bad: if it could make you eat less prepared meals and processed foods …

Do not forget that red meat is a great source of saturated fats. So do not abuse it. But concerning white meat: no restriction. Phew the turkey rice lovers are saved!

Above all, do not stop eating eggs, coffee, vinegar, fish, nuts, meat or whey (so-called acidifying food) to have a more basic blood pH or for fear of having osteoporosis, what bullshit!

The final word: nothing can replace, in terms of health, a balanced, diversified diet, ensuring that the daily energy intake does not exceed the needs.


Read also:

The Complete Guide to the Ketogenic Diet

Complete guide to understand the 5: 2 diet

Complete guide on the Dukan diet to lose weight

The benefits of the Mediterranean diet

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