Alkaline food contains many metal elements, such as calcium, potassium, sodium, iron, magnesium and zinc. After being absorbed and metabolized by the body, basic oxides with cations are generated, which can buffer acidic metabolites. Alkaline foods include vegetables, seafood (kelp, laver, seaweed and Undaria pinnatifida), fruits, tea and coffee. Milk and yogurt are also alkaline foods, even oranges, hawthorn, tomatoes and apricots that taste sour are also alkaline foods.
Animal viscera, muscle, fat, protein and grain are rich in sulfur (S), phosphorus (P) and chlorine (Cl), which are metabolized in human body to produce sulfuric acid, hydrochloric acid, phosphoric acid and lactic acid, which are the sources of acidic substances in human body. However, most vegetables, fruits, kelp, beans and dairy products contain many elements such as calcium (Ca), potassium (K), sodium (Na) and magnesium (Mg), which can become alkaline substances after metabolism in the body.
Alkaline food reacts with carbon dioxide after entering the human body to generate carbonate, which is excreted with urine, while acidic food generates ammonium salt in the kidney and is excreted, thus maintaining the normal PH value of blood. The blood pH of normal people is 7.35, which is weakly alkaline. The PH range is 1 ~ 14, and the PH value of water is 7 (neutral). Below 7 is acidic, and above 7 is alkaline.
If you eat too much acidic food and can't neutralize it, it will lead to acidity and consume basic elements such as calcium, potassium, magnesium and sodium, which will lead to blood color deepening, viscosity increasing and blood pressure rising, thus causing acidosis. Young people can induce skin diseases, neurasthenia, hyperacidity, constipation and tooth decay, while middle-aged and elderly people are prone to hypertension, arteriosclerosis, cerebral hemorrhage and gastric ulcer. Acidosis is because you eat too much acidic food and can't be partial to food. You should eat more vegetables and fruits to keep the acid-base balance in your body.
Although fruit contains all kinds of organic acids, it tastes very sour, but most of it is oxidized into alkaline food after digestion. However, strawberry has organic acids (benzoic acid and oxalic acid) that cannot be oxidized and metabolized, which will increase the acidity of body fluids. They are all acidic foods, with one exception. The main organic acids in vegetables are malic acid, citric acid, tartaric acid and oxalic acid. Here we should pay special attention to oxalic acid, its organism is not easy to oxidize, and calcium oxalate formed with calcium salt is insoluble in water and accumulates in the kidney, which affects the absorption of calcium. Among vegetables, tomatoes, potatoes and spinach all contain oxalic acid. In theory, alkalosis can also occur, but alkalosis is not common in humans, because humans have a lot of stomach acid to neutralize.