The acid-base (pH) value of blood is determined by the number of minerals and hydrogen ions contained in blood. Once the blood is acidic or alkaline, the kidney will turn the excess acidic or alkaline substances into urine to keep the blood weakly alkaline. As long as the pH value of human blood and body fluids changes a little, it will cause metabolic disorder and confusion. Therefore, the human body has a good acid-base self-regulation system, which keeps the body fluid at a constant pH value and buffers the influence of food acid and alkali.
The acidity and alkalinity of food is not based on taste, but on the "mineral content" in food. There are eight minerals closely related to the acidity and alkalinity of food: potassium, sodium, calcium, magnesium, iron, phosphorus, chlorine and sulfur. The first five are alkaline after entering human metabolism; The latter three (phosphorus, chlorine and sulfur) are acidic. (The acidity and alkalinity of food can be known by drying food and burning it to ashes, and then neutralizing it with acid-base titration, which is a process of simulating the burning and metabolism of food in the body.
When a certain kind of food is judged to be acidic or alkaline, it depends entirely on the content ratio of acidic elements and alkaline elements. The so-called acidic food means that after digestion and absorption, the food produces more anions such as phosphate (Po43-), sulfate (So42-) and chloride (Cl-) than cations such as sodium (Na+), potassium (K+), magnesium (Mg2+), calcium (Ca2+) and iron (Fe3+). On the other hand, if there are more cations, it is easy to produce more alkali in the body, because cations can make the body retain more bicarbonate ions and form an alkaline reaction. Simply put, foods containing more minerals such as sulfur, chlorine and phosphorus are acidic foods; And foods containing more minerals such as potassium, calcium, magnesium, sodium and iron are alkaline foods.
The problem is that once there are too many acidic substances in the body, the acid-base self-regulation system will excrete alkaline minerals as well as acidic substances. Therefore, when discussing acidic and alkaline constitutions in nutrition, the focus will still return to the theme of "nutritional balance". If foods with high mineral content are ingested too little or acidic substances are ingested too much, it is easy to create an acidic environment, and vice versa. No matter whether it is acidic or alkaline, it is not very good for the body, because the body will try to adjust the acid-base concentration in order to maintain the normal weak alkali constant state, so excessive acid or alkali will increase the burden on the kidneys and lungs when making adjustments.
How to judge acidic and alkaline foods?
Judging from the six categories of food, whole grains, meat, fish and eggs are all acidic foods. Meat contains more sulfate and whole grains contain more phosphate. As for the hobby drinks such as soft drinks, they are acidic foods because "phosphorus" will be added in the manufacturing process. Milk, vegetables and fruits are mostly alkaline foods. Milk is rich in phosphorus but contains more calcium, so it is an alkaline food. The composition of salt is sodium chloride, which dissociates as many chloride ions as sodium ions in the body, just in the acid-base balance. To sum up simply, animal foods, except milk, are mostly acidic foods; In plant foods, except for whole grains and some nuts and beans, most of them are alkaline foods.
List of acid/alkali foods
Hyperalkalinity
◆ Fruit:
Lemon, plum, raisin
◆ Vegetables:
Kelp, laver, rhizoma Amorphophalli, onion, coriander, spinach, cauliflower, garlic, green pepper, sweet potato leaves, water spinach, chrysanthemum morifolium, Gracilaria lemaneiformis, rape and Chinese cabbage.
◆ Drinks:
Sugar-free scented tea, sugar-free ginger tea, freshly squeezed fruit and vegetable juice (without added sugar)
Moderate alkaline
◆ Fruit:
Orange, papaya, fig, guava, watermelon, blueberry, apple, raw olive and pear.
◆ Vegetables:
Tomato, chicory, spinach, cabbage, water spinach, Chinese cabbage, broccoli, perilla, alfalfa sprouts, okra, cucumber, kale, bitter gourd, konjac, garlic, green onion, ginger, nine-story tower.
◆ Rhizomes:
Beet, ginger, carrot, burdock, yam, taro and lotus root.
◆ Beans and bean products:
Soybean, bean curd, dried bean curd, bean curd, miso
◆ Seasoning:
Black pepper, white pepper, curry, rosemary, Daphne odora, star anise, thyme, miso, pure fruit vinegar and natural vinegar.
◆ Dairy products:
breast milk
◆ Drinks:
Green tea, mineral water, fruit vinegar, aged vinegar.
◆ Sweetener:
Stevia, oligosaccharide, fructooligosaccharide, sugar substitute (aspartame)
Slightly alkaline
◆ Fruit:
Oranges, bananas, strawberries, cherries, pineapples, mangoes, peaches, cantaloupes, avocados, apples, dried longan, grapes, kiwis and grapefruit.
◆ Vegetables:
Celery, corn, eggplant, pepper, sweet pepper, pumpkin, cucumber, loofah, pea, string bean, Dutch bean and loofah.
◆ Mushroom/seaweed:
Mushrooms, Flammulina velutipes, Pleurotus eryngii, Auricularia auricula, Auricularia auricula, Porphyra, Coral Grass, and Kelp.
◆ Rhizomes:
White radish, sweet potato, bamboo shoot, lotus root, taro, yam, pumpkin, white radish, potato, sweet potato and onion.
◆ beans:
Red beans, mung beans, edamame, lentils
◆ Nuts:
Black sesame, white sesame, pumpkin seeds, sunflower seeds, pumpkin seeds, chestnuts, cashews, walnuts, almonds and pine nuts.
◆ Seasoning:
Sesame sauce, pure fermented soy sauce, brewed vinegar, natural salt (rock salt, sea salt, lake salt)
◆ Oil:
Cold pressed bitter tea oil, cold pressed olive oil, cold pressed linseed oil, cold pressed coconut oil, cold pressed sesame oil and cold pressed peanut oil.
◆ Class:
Millet, wild rice, germinated rice
◆ Eggs: preserved eggs
◆ Dairy products: raw goat milk
◆ Drinks:
Less sugar ginger tea, sugar-free black coffee, sugar-free soybean milk.
◆ Wine: Fermented wine
◆ Others: beer yeast
Neutral/slightly acidic
◆ Fruit:
Plums and persimmons
◆ Vegetables:
asparagus
◆ Egg: protein
◆ Class:
Wheat germ, oat, brown rice, white rice, germ rice, black glutinous rice, wheat, barley, buckwheat, peanuts and corn.
◆ beans:
Broad beans, black beans and snow lotus seeds
◆ Nuts:
Walnuts, cashews, peanuts, walnuts
◆ Seasoning:
Pure brewed soy sauce paste, firewood and fish powder, sand tea sauce, oyster sauce and refined salt.
◆ Oil:
Bitter tea oil, olive oil, sesame oil, peanut oil, unrefined corn oil, unrefined soybean oil, deep sea fish oil and seal oil.
◆ Meat:
Wild animal meat, wild fish
◆ Dairy products:
Yogurt, raw milk, high-temperature sterilized goat milk
◆ wine:
red wine
◆ Sweetener:
Refined honey, brown sugar, sucrose
Moderate acidity
◆ Class:
Corn, buckwheat, oats, rye, sorghum
◆ Fish and meat:
Cattle, sheep, pigs, chickens, ducks, geese, beef liver, fresh cultured shellfish, tuna,
◆ Eggs: Eggs
◆ Oil:
Refined salad oil, refined coconut oil, cream, lard, butter.
◆ Dairy products:
High temperature sterilized milk
◆ Seasoning:
Soy sauce and vinegar
◆ Drinks:
Flavored coffee, milk tea
◆ wine:
Dark beer, white wine
◆ Snacks:
Sugar-free chocolate, pineapple cake.
◆ Sweetener:
White sugar, rock sugar
High acidity
◆ Class:
White rice, wheat, white flour
◆ Fish and meat:
Squid, viscera of all animals, dried products of fish and shellfish, oysters, crabs and shrimps.
◆ Eggs: duck eggs and yolk.
◆ Oil:
Hydrogenated vegetable oil (margarine, vegetable butter, palm oil), all oxidized oils.
◆ Dairy products:
Cheese, whipped cream, ice cream
◆ Seasoning:
High fresh monosodium glutamate
◆ Drinks:
Soda, coke
◆ wine:
Draft beer, Gin, vodka, sorghum, rice wine, Shaoxing wine.
◆ Snacks:
All high-sugar biscuits and sweets