Acidic substances and acidic foods are two different concepts. Before being absorbed and metabolized by the body, it is an acidic substance. Generally speaking, all sour substances are acidic substances. When acetic acid entered the field of food nutrition from the chemical field, acetic acid became an alkaline food.

The pH of acid-alkaline foods is not necessarily related to the pH of the substance before entering the human body. To determine the acidity or alkalinity of food, we mainly look at the alkaline elements contained in the food, the results of the metabolism of acidic elements and organic acids in the human body. Usually, the simple way to determine is that any food containing high levels of non-metallic elements such as chlorine, phosphorus, phosphorus, etc. Food, because after being ingested into the human body, the final metabolites are acidic, and most of them are acidic foods. Foods containing more metal elements such as calcium, potassium, sodium, and magnesium are mostly alkaline foods because their final metabolites are alkaline after being ingested into the human body. The acetic acid entering the human body undergoes a series of biochemical reactions and finally generates carbon dioxide and water. The carbon dioxide is eliminated by the lungs, thus reducing the carbonic acid content in the blood and making the body fluids weakly alkaline. Acetic acid is an alkaline food.