Lactic acid (lactate) is a substance from the carboxylic group. In the human body, it is a product of glycolysis (breakdown of glucose). It is found in the cells of the brain, liver, heart, muscle tissue and other organs.

general characteristics

Lactic acid, or Lactic acid (formula - CH3CH (OH) COOH) belongs to the AHA substances (alpha hydroxy acids). For the first time, lactic acid was discovered by the Swedish researcher Karl Scheele in 1780 in the muscles of animals, in some microorganisms, as well as in the seeds of individual plants. A few years later, another Swedish scientist, Jens Jakob Berzelius, was able to isolate lactates (lactic acid salts).

Lactate is a non-toxic, almost transparent (with a yellow tint) odorless substance. It is soluble in water (at a temperature of about 20 degrees Celsius), as well as in alcohol and glycerin. High hydroscopic properties make it possible to create saturated lactic acid solutions.

Role in the body

In the human body, glycolysis converts glucose into lactic acid and ATP. This process takes place in muscle tissues, including the heart, which is especially important for the enrichment of the myocardium with lactic acid.

In addition, lactate is also involved in the so-called reverse glycolysis, when it is formed as a result of certain chemical reactions. This transformation takes place in the liver, where lactate is concentrated in large quantities. And the oxidation of lactic acid provides the energy necessary for the process.

Lactic acid is a significant component of chemical reactions in the body. This substance is important for metabolic processes, muscle function, nervous system and brain.

Concentration in the body

It is the concentration of lactic acid in the body that determines the quality of carbohydrate metabolism and the level of tissue oxygenation. In the body of a healthy person, the blood lactate content ranges from 0.6 to 1.3 mmol / liter. Interestingly, most seizure diseases cause an increase in this indicator. An increase of 2-3 times occurs with especially severe disorders.

Lactic acid exceeding the normal range may indicate an oxygen deficiency. And he, in turn, is one of the symptoms of heart failure, anemia or impaired lung function. In oncology, an excess of lactate indicates the possible growth of malignant tumors. Serious liver diseases (cirrhosis, hepatitis), diabetes mellitus also cause an increase in acid levels in the body.

Meanwhile, the presence of lactate in excess is not only a sign of serious illness, but also causes the development of other pathologies. For example, increased blood acidity leads to a decrease in the amount of alkali and an increase in the level of ammonia in the body. This disorder is called acidosis by doctors. It is accompanied by a disorder of the nervous, muscular and respiratory systems.

It is also important to know that intensive production of lactic acid is possible in a healthy body after intense sports activities. It is easy to understand that the concentration of lactate has increased from muscle pain. However, immediately after exercise, lactic acid is flushed out of the muscles.

Another non-disease-related cause of increased lactic acid concentration is age. Experiments have shown that in older people, an excessive amount of lactate accumulates in the brain cells.

Daily rate

There is no such thing as "daily lactic acid intake", as well as there is no clearly defined amount of consumption of foods containing lactate. Although there is no doubt that people with a sedentary lifestyle who do not play sports should consume more food with lactic acid. Usually, 2 glasses of kefir per day are enough to restore balance. This is enough for the acid molecules to be easily absorbed by the body.

The increased need for lactate is felt by children during the period of intensive growth, as well as by adults during intellectual work. At the same time, the elderly body does not need to consume high doses of lactic acid. The need for a substance also decreases against the background of a high level of ammonia, with diseases of the kidneys and liver. An excess of a substance may be indicated by convulsions. Problems with digestion, loss of strength, on the contrary, indicate a lack of substance.

Lactic acid harm

Almost any substance in excess cannot be useful for the human body. Lactic acid in a pathologically high concentration in the blood leads to the development of lactic acidosis. As a result of this disease, the body "acidifies", the pH level drops sharply, which subsequently leads to dysfunction of almost all cells and organs.

Meanwhile, it is worth knowing that against the background of intense physical work or training, lactic acidosis does not occur. This disease is a side condition in severe diseases such as leukemia, diabetes, acute blood loss, sepsis.

Speaking about the dangers of excess lactic acid, one cannot but recall that some drugs also cause an increase in the concentration of lactate. In particular, adrenaline or sodium nitroprusside can cause lactic acidosis.

How to get rid of excess acid

Bodybuilders belong to the category of persons in whose body (due to objective circumstances) the level of lactic acid regularly rises. The following techniques will help remove excess lactates from the body:

1. Start the workout with a warm-up and finish with a hitch.
2. Take isotonic drugs containing bicarbonates - they neutralize lactic acid.
3. Take a hot bath after training.

And by the way, the acid level is always higher in beginner athletes. Over time, the concentration of lactate increases moderately.

Lactate for athletes

The lactic acid produced during exercise fuels the body, helping to build muscle. In addition, lactate dilates blood vessels, improves blood flow, as a result of which oxygen is better transported throughout the body, including muscle tissue.

As a result of the experiments, a connection was established between the growth of lactic acid and testosterone. An intense release of the hormone occurs after 15-60 seconds of increased physical activity. In addition, sodium lactate in combination with an anabolic effect on muscle tissue. This prompted researchers to think about the possible use of lactic acid as a drug for muscle building. However, these are still only guesses that need to be tested.

Food sources

If you remember that lactic acid is the result of fermentation processes with the participation of lactic acid bacteria, it becomes easier to learn the list of foods rich in beneficial substances. With this knowledge, you do not have to look at the label every time in search of the right ingredient.

The most concentrated sources of lactate are dairy products. In particular, these are whey, kefir, sour cream, cottage cheese, fermented baked milk, yogurt, ayran, hard cheese, ice cream, yoghurts.

Other products containing lactic acid: sauerkraut, kvass, Borodino bread.

Application in cosmetology

As already noted, lactate belongs to the group of AHA acids. And these substances contribute to the exfoliation of dead particles of the epidermis. Due to this and other properties, lactic acid is actively used in cosmetology.

In addition to exfoliation, lactate as a cosmetic is capable of:

• eliminate inflammation, cleanse the skin of harmful microorganisms;
• whiten, remove age spots;
• remove cuticles without damaging the skin;
• treat acne;
• moisturize, improve elasticity, strengthen sagging skin;
• smooth expression lines and reduce deep wrinkles;
• get rid of stretch marks on the skin;
• narrow pores;
• accelerate the regeneration of the epidermis;
• regulate the acidity of the skin;
• improve the condition of oily skin;
• give a platinum tint to blonde hair;
• eliminate the smell of sweat.

On women's forums, there are often positive reviews about lactic acid - as a component of natural home-made cosmetics. As a beauty product, lactate is used as a component of soaps, shampoos, creams and serums for skin rejuvenation, in peeling or depigmentation products. Lactic acid is also included in intimate hygiene cosmetics as an antibacterial compound.

Lactic acid can be added to finished cosmetics. For example, in a peeling preparation, lactate can be about 4 percent, in soaps, shampoos and balms - about 3 percent, in tonics and creams no more than 0.5 percent of the total composition. But before you improve the finished products with lactate or create homemade cosmetics, you need to do a test for the individual tolerance of the substance. It is also important to know that pure lactic acid can cause death of mucous membranes, and excessive consumption of drugs with lactate, although it does not create a toxic effect, dries the skin.

It is safer to use the remedy of our grandmothers and great-grandmothers and use products rich in lactic acid as cosmetic products. For example, a 30-minute curdled milk mask will restore shine to dry hair, and a kefir face mask will prevent early aging, remove pigmentation and freckles.

Other applications

Lactate concentrate has been shown to be effective in removing warts, calluses, and tartar.

In the food industry, lactic acid is known as the E270 preservative additive, which improves taste. This substance is believed to be safe for humans. It is a part of salad dressings, confectionery, and milk mixtures for children.

In pharmacology, lactate is used to create bactericidal agents. And in the light industry, this substance is used in the manufacture of leather goods.

Today you have learned the most interesting facts about lactate and its effect on the body. Now you know how to use lactic acid for maximum benefits for your health and good looks. And most importantly - where to look for the sources of this useful substance.

When considering such topics, which require in-depth knowledge of chemistry, biology and physiology, cause-and-effect relationships are constantly confused. But it must also be admitted that today, many of our ideas about the work of the body are mainly guesses. They are based on findings, which can sometimes change dramatically over time.

Aerobic regimen

Our body is aerobic... That is, it cannot exist without air. For chemical and biological reactions occurring at the molecular level, you need oxygen... Therefore, so to speak, we constantly exist in aerobic regimen, or, in other words, completely dependent on oxygen.

Anaerobic mode

But later, biochemists found out that cells can continue to work without enough oxygen (or even without it at all) and still break down glucose (our main universal fuel source). That is, do everything the same, but already in anaerobic mode.

ATF

In both cases, our cells produce from glucose aTP molecules (adenosine triphosphate), which provide energy for all chemical processes.

Glycolysis

The process of assimilating glucose is called glycolysis... Other chemical compounds formed as a result of glycolysis are pyruvate (pyruvic acid) and lactic acid.

It is believed that pyruvate is a result of aerobic activity, and lactic acid is anaerobic. This is not entirely true, but it does not change the essence.

Pyruvate

It is the most important intermediate product of energy metabolism. One of the main roles of pyruvate in the body is to participate in the Krebs cycle.This is a cycle of interactions between chemical elements and enzymes, as a result of which the fuel cells of ATP or its immediate precursors are formed.

Lactic acid

In popular fitness magazines, it is generally accepted that there is a turning point in training when, due to a lack of oxygen, when the load is exceeded, lactic acid is formed in the muscles. This is the cause of all problems - from quick fatigue to pain, which "flushes" from the body in a couple of days. This description of processes is extremely incorrect and misleading.

Lactate

The fact is that lactic acid is always produced (and not only lactic acid). And at rest too. But by itself, it does not affect anything, since it instantly breaks down into components. We can even say that it already appears before us in the form of initial elements, leaving the cell.

One of the components of this decay (dissociation) is lactate- lactic acid salt. Therefore, it is more appropriate to talk about lactate levelrather than lactic acid. Accordingly, the question "how to remove lactic acid from the muscles" is absurd, since it is simply not there.

It is even more wrong to equate lactic acid and lactate, implying that they are the same thing. Indeed, sometimes in biochemistry these two concepts are equated, but in completely different circumstances, for example, when the total acidity can be ignored. In our case, such a comparison led to long-term data distortion in the study of chemical processes.

Lactate, meanwhile, also has no harmful effect on muscles, does not cause pain and is not involved in fatigue. Moreover, it is not a by-product in itself, but an extremely fast fuel at peak load. The vast majority of it is eliminated by the liver (and directly by cells) in this way. Moreover, it returns to the normal level (at rest) within an hour.

It should be noted that many chemical and energy processes in the body are reversible. This also applies to lactate, which is easily synthesized from pyruvate (and another enzyme, NADN). Such transformations of elements make it possible to optimize the circulation and storage of substances throughout the body and to urgently transport them to inaccessible places if necessary. For example, through cell membranes.

The acidity of the intracellular environment

As we found out earlier, you can forget about lactic acid as such (but not about lactate). However, you will not be able to forget about the second component formed during its decay - free protons or, to be precise, hydrogen cations H +... They are able to change the pH (acidity) of the intracellular environment, including greatly increase it with increasing concentration, up to acid.

The formation of hydrogen cations is an inevitable condition for glucose uptake. Especially in anaerobic mode. There's a good reason to blame lactate in acidity growth... However, upon closer examination, it turns out that some of the reactions that make up glycolysis lead not to an increase, but to a decrease in the acidity of the medium. For example, during the synthesis of lactate from pyruvate, in which a proton is taken, lactate is excreted from the cell by a protein, which also uses another proton for this.

It is now known that the main source of protons in an actively working muscle cell is the breakdown of ATP. therefore metabolic acidosis - acidification of the environment of muscle cells during intense exercise is associated precisely with the use of ATP energy. And it is not associated with the synthesis and accumulation of lactate, which is contrary to the well-established misconceptions.

“This production (as well as the release of lactate into the blood) requires the consumption of protons, reducing their concentration in the cell. Therefore, the formation and accumulation of lactate can serve as a good indicator of acidification of the cellular environment, but they are not related as a cause and effect. " - magazine Physiology.

Lactate level

The increase in lactate levels is not directly related to oxygen deficiency, as previously thought, but may indirectly indicate it. Its accumulation occurs due to the low rate of processing of substances and their transformation into energy in an anaerobic mode, which, however, must be trained.

Acidity regulator, acidifier, preservative, hydrolysis and inversion catalyst.

2-Hydroxypropanoic acid.

Colorless to slightly yellowish syrupy liquid with a sour taste.

Chorus. sol., miscible with water and alcohols; Wed sol. on the air; immoral. in fatty solvents.

Natural source

In many fruits, wines, yogurt, sauerkraut; during exercise it is formed in the muscles.

Receiving

Enzymatic from sugar-containing raw materials; the interaction of ethylene oxide and cyanide with subsequent saponification (3-hydroxypropionic acid is formed as an impurity); catalyzed by the reaction of acrylonitrile with water. Impurities: polylactic acid, 3-hydroxypropionic acid, oxalic acid.

L- Lactic acid is absorbed with a release of about 3 kcal / g. D-lactic acid is converted by racemases to L-lactic acid and then absorbed. The content of racemase in the body of infants is not always sufficient for this.

Particleboard not defined. In nutrition for infants, only C +) - lactic acid is allowed. Hazards according to GN-98: MPC in water 0.9 mg / l, hazard class 4. Codex: approved as an acidity regulator in 23 food standards: in 5 standards for canned fruits, berries, vegetables, GMP mushrooms; in GMP canned fish standards; canned olives and breakfast cereals, incl. for children, up to 15 g / kg; jams, jellies and citrus marmalades to maintain a pH of 2.8-3.5; tomato pulp to maintain pH above 4.3; complementary feeding of children of the first year of life GMP; canned baby food up to 2 g / kg; low-fat margarines, broths, soups, GMP cottage cheese; processed cheeses up to 40 g / kg. In the Russian Federation, it is allowed in nectars in

amount up to 5 g / l (p. 3.1.5 SanPiN 2.3.2.1293-03); in fruit juices in an amount of up to 3 g / l (p. 3.1.2 SanPiN 2.3.2.1293-03); into jams, jellies, marmalades and other similar products, including low-calorie products, into non-emulsified vegetable and animal oils and fats (except for oils obtained by pressing and olive oil), specially intended for culinary purposes, into whey cheeses, canned fruits and vegetables, into pasta, bread, beer in quantities according to TI (clause 3.1.6,3.1.14,3.1.17,3.1.18,3.1.20,3.1.21,3.1.22 SanPiN 2.3.2.1293-03); as an acid in food products according to TI in an amount according to TI (clause 3.2.12 SanPiN 2.3.2.1293-03); as an improver for flour and bread in bread, bakery and flour confectionery products in an amount according to TI (clause 3.7.6 SanPiN 2.3.2.1293-03).

As a flavoring additive with a mild sour, easily muffled taste for drinks, pickled vegetables, desserts, caramel; buffer acidifier for confectionery and bakery products; preservative in pickled vegetables (the concentration should be relatively high); catalyst for inversion of sugar syrup in the absence of hydrochloric acid. Consumption of lactic acid 40-45% concentration is 4 liters per 1 ton of sugar.

Lactic acid is used in conjunction with diammonium phosphate to intensify the malting process. Acid consumption is 1.5 liters per 1 ton of soaked barley. The acid is used diluted 1:15. In brewing, lactic acid is also used to acidify the mash.

Food lactic acid in accordance with GOST 490-79 “Food lactic acid. Specifications ”is included in the list of raw materials in GOST 171-81“ Pressed bakery yeast. Specifications ", GOST 240-85" Margarine. General specifications ", GOST 7180-73" Pickled cucumbers. Specifications ”, GOST 12712-80“ Special vodkas and vodkas. Specifications ”, GOST 27907-88“ Vodkas for export. General technical conditions ".

Other areas of application: in cosmetics and animal feed, in the production of emulsifiers, lactates, esters.

System name:2-hydroxypropionic acid.

Possible names:lactic acid, E-270, lactic acid, E 270 (as a food additive), lactic acid.

Chemical formula: CH3CH (OH) COOH.

Molek. weight: 90,1.

T. pl. \u003d 18оС.

Receiving:

• formed during the fermentation of lactose and sugar-containing raw materials by lactic acid bacteria (in sour milk, sauerkraut, during the fermentation of beer and wine) was discovered in 1780 by Karl Scheele;


• in the body, lactic acid is formed during the breakdown of glucose;


• D-lactic acid is found in tissues of animals, plants, and also in microorganisms

Lactic acid properties:

1. in soap making: in an alkaline solution for production, in a finished soap mass as an active component and acidity regulator;


2. to improve the penetration of other active ingredients into the skin;


3. cleansing, regenerating, anti-aging creams, serums, lotions;


4. acidity regulator;


5. peels - promotes exfoliation of superficial keratin scales (chemical peeling), have a powerful moisturizing and moisture-retaining effect, activate the immune system and give the skin renewal, softness and velvety


6. as a depigmenting agent for removing pigmentation (freckles, age spots, lentigo, chloasma).


7. shampoo - promotes cell regeneration and renewal, moisturizes and regulates the pH (acidity) of the shampoo


8. used for douching with leucorrhoea


9. intimate cosmetics - as a regulator of acidity Normally, the reaction of vaginal contents is acidic pH 3.3 (at different age and physiological periods it can change up to 5 - mainly due to improper nutrition, the body becomes alkalized, which contributes to the development of fungi)


10. in concentrated form, lactic acid is used to cauterize warts and remove corns;


11. 1% lactic acid solution is used as a mouthwash to remove tartar;


12. other application: in the food industry, in mordant dyeing, in leather production, in fermentation shops as a bactericidal agent, for the production of medicines, plasticizers.

• the limiting amount of adding lactic acid to soap is up to 3%.


• tonics, creams 0.1-0.5%


• hair products 1-3%


• home peels - up to 4%


• professional cosmetic lines can contain up to 20-30% lactic acid.

Rules for the use of lactic acid

• Be sure to pre-check cosmetic preparations with lactic acid for individual tolerance on a small area of \u200b\u200bthe skin


• use with caution on sensitive skin, do not apply to the area around the lips and eyes, where the skin is especially thin


• be sure to use cosmetics with UV filters; it is not advisable to use ANA in the spring-summer period, since young skin cells are more sensitive to ultraviolet radiation, the risk of unwanted pigmentation increases


• cosmetic products with a minimum concentration of lactic acid can be used for daily skin care both in winter and in summer


• the optimal value of cosmetics with lactic acid is pH 3-3.5; at pH \u003d 7 (neutral environment), the ability of ANA to stimulate the processes of renewal of skin cells practically disappears


• it is desirable to additionally introduce components that soothe the skin and antioxidants into the formulations of cosmetics with lactic acid


• lactic acid dissolves in the aqueous phase when heated or is introduced at the end of the manufacture of a cosmetic product


• not compatible with xanthan.

Precautions

• in its pure form, lactic acid can cause necrosis of the mucous membranes.


• cosmetics containing lactic acid can dry out the skin.


• do not use on damaged skin.


• lactic acid is a weak acid with low toxicity. Even exceeding the dosage by 8 times does not harm. Subject to the rules of use and dosage, no side effects are observed.

Storage

Solubility:

Lactic acid, also called hydroxypropionic acid or lactate, is an organic substance released during lactic acid fermentation, for example, when souring milk or preserving vegetables. It is present in the tissues of living things, including muscles, blood, and urine. It can be produced by bifidobacteria, lactobacilli and actinomycetes - microorganisms that live in the intestines. Some other bacteria that inhabit the intestines feed on lactic acid, converting it into other compounds that the body needs. Lactate is widely used in veterinary medicine as an antiseptic, as well as for the normalization of digestive processes.

Composition, release form and storage conditions

Lactic acid is a syrupy, colorless, or slightly yellowish substance, with a subtle specific odor, and sour taste. It contains about 75% of lactic acid proper and about 15% of its anhydride. Has a specific gravity of ~ 1.2. Mixes up in any ratio with water, ether, alcohol and glycerin. In veterinary medicine, natural lactate is usually used, less often synthetic.

Lactic acid is produced in glass vials or polymer bottles with a volume of 20, 100, 200, 500 and 1000 ml. The concentration of the drug is 40%, or 80%.

If lactic acid gets on the surface of the skin, it must be washed off with soap and water, if exposed to mucous membranes, rinse with plenty of warm water.

Store the drug away from food and household chemicals, in a place inaccessible to animals and children, at temperatures from -40 ° C to + 35 ° C, for ten years.

The healing properties of lactic acid

When administered orally, a lactic acid solution has an antiseptic and anti-fermentation effect. Weakens spasms of the sphincters of the digestive tract, promotes faster progression of the chyme. Stimulates the digestive glands.

Strengthens the motility of the scar, mesh and book, the formation of gum. Produces an irritating effect on the mucous membranes of the digestive system, accelerating metabolic processes. Undiluted lactate leads to mucosal necrosis.

When applied externally, the solution has the following properties:

• disinfectants (10-30%);
• keratolytic (10%);
• cauterizing (10-50%).

Indications for use

Lactic acid is used to treat various diseases in cattle, goats, sheep, chickens, externally or internally.

• With trichomoniasis in cows, a 0.5-1% solution of lactate is used for vaginal douching.
• Two tablespoons of the drug, diluted in ten liters of water, are soldered to rabbits during the day to improve the absorption of feed. Disinfection of rabbit feed is carried out with a 4% solution of lactic acid.
• To strengthen immunity, increase egg production and weight gain for chickens, 0.5 ml of a 40% solution per 1 kg of feed are added every day. This has a positive effect on the strength of the eggshell.
• In the form of a cauterizing agent, lactic acid is used to disinfect the air of incubators and poultry houses (against pathogens such as typhoid, cholera, pullorosis, respiratory mycoplasmosis and infectious laryngotracheitis of birds). 15-20 ml of acid are consumed per 1 m³ of space. Lactic acid vapors have a detrimental effect on streptococci and staphylococci, therefore lactate is used for aerosol disinfection of livestock buildings.
• For the prevention of respiratory diseases in calves and chickens, lactic acid is used together with triethylene glycol iodine (for chickens - 0.5 ml, for calves - 0.5-1 ml of a 40% solution per 1 kg of feed).
• Outwardly, a 10-50% solution of lactic acid, ointments and pastes containing it are used to treat ulcers of the mucous membranes and skin, warts, corns, fistulas of the hoof cartilage. An 80% solution removes neoplasms and has a keratolytic effect on the growth of keratinized tissue.

For the treatment of tympanic rumen in cattle, goats and sheep, as well as flatulence, hypoacid gastritis, acute expansion and chronic inflammation of the stomach, gas formation in horses, pigs, rabbits, dogs and fur-bearing animals, lactic acid is used internally.

For this, an aqueous solution of the drug is used, the concentration of which does not exceed 2% (that is, 20 ml of water is added to 1 ml of 40% lactate, or 100 ml of water is added to 5 ml of 40% lactate). It is given to animals in the following doses:

In case of acute diarrhea, piglets can be given the drug in a dose of 0.5-1 ml. But when the disease becomes chronic, the use of lactic acid becomes useless.

An aqueous solution of lactate can be used to treat the surface of meat products. Thus, most of the microflora present on them will be destroyed, and the surviving microorganisms will significantly slow down their development. PH will stabilize to 4.0-5.4. Such processing does not affect the quality indicators of meat products.

There is no information on cases of drug overdose. Even with an eight-fold excess of the dose recommended by the instructions for use, lactic acid does not harm the animal's body. Contraindications include: tuberculosis, acute liver failure, hyperacid gastritis, weeping ulcer on the body. After the use of lactic acid, animal products are allowed to be used without any restrictions.