Let’s first briefly popularize the basic theory of human acid-base balance: the acidity and alkalinity of different parts of human body (expressed by pH value, pH = 7 is neutral, less than 7 is acidic, more than 7 is alkaline) are different: for example, gastric juice is acidic, intestine is weakly alkaline; kidney will adjust the pH of urine according to the different metabolic conditions in the body, so that the pH value in blood is basically balanced between 7.35 and 7.45. In this way, the pH of blood is basically balanced between 7.35 and 7.45. A pH lower than 7.35 is acidosis and higher than 7.45 is alkalosis. Normal human body fluid is a typical buffered solution with a very strong ability to maintain acid-base balance and very little pH fluctuation, and we often refer to body fluid as endostasis. An imbalance in acid-base balance is not caused except in cases of severe vomiting, diarrhea, lack of oxygen, and serious illnesses that prevent the kidneys from excreting excess acid or alkaline substances in a timely manner. On the contrary, even if you can drink a bottle of vinegar or swallow a bottle of calcium tablets in one gulp, the effect on the pH of body fluids will only last for a few minutes at most, after which the gastric juice is still acidic, the intestinal tract is still alkaline, and the pH of body fluids is still stable at about 7.4. After understanding the theory of acid-base balance in the human body, it is untenable to go back and look at the so-called acid-base body and food pH theory. But even in the United States, there is still a small group of experts promoting this theory, and a book called “The Acid-Alkaline Food Guide” is still selling well in the United States. According to the authors of this book, strenuous exercise causes lactic acid to build up, certain acidic foods increase the concentration of chloride ions in body fluids, eating large amounts of protein increases organic acids, and the body must increase the release of calcium ions from bone, increase the outflow of potassium and magnesium ions from cells and body fluids, and increase the burden on the kidneys, lungs and skin to remove excess acidic ions. In the long run, this can lead to osteoporosis, muscle weakness, overloading of the body’s organs, and eventually various medical conditions, as well as the development of cancer. However, these explanations are not supported by scientific theories, and no experimental research results approved by peer experts can be found; as for the relationship between the “acidic body theory” and the development of cancer, which was proposed by the Nobel Prize winner, it has never been found in the corresponding literature. On the contrary, judging from our common sense, the per capita life expectancy in developed countries is longer than that in less developed countries, and the per capita life expectancy of modern people is much longer than that of ancient people. Although this is mainly due to the great achievements of medical science, if we look at the acidity and alkalinity of food alone, modern people must consume more acidic food than ancient people, because the latter cannot afford to eat acidic substances due to economic constraints, their diet is mainly starch and vegetables, and they eat very little high-protein food, more of them should be “alkaline “, should rarely get sick, there should be no shortage of longevity, but why is “life 70 years old”? From the point of view of modern medicine, long-term high protein, high sugar and high fat diet will easily lead to obesity and increase the risk of cardiovascular diseases, and may also increase the incidence of certain tumors, but there is no scientific basis for the statement that “alkaline people should not have tumors”. Moreover, if we strictly control the protein intake according to the guidelines of “food acid-base theory”, we will have health problems due to malnutrition. Therefore, I don’t think we need to be scared by such alarmist theories. In our medical field, in addition to acidosis and alkalosis, there are also water poisoning and oxygen poisoning …… If they are used and played, I am afraid that new theories and doctrines will come out tomorrow.