The amino acid cysteine, like most biomolecules, is divided into two types: L- and D-isomers. The forms differ only in alpha carbon atoms, which do not affect the chemical properties in any way, and their physical properties differ insignificantly. Instructions for the use of cysteine depend on the purpose: in sports, medicine, and the amino acid is also used for the prevention of diseases and for cosmetic purposes.
The spectrum of action of the substance is extensive; it is even used in the food industry. One form of cysteine is assigned the code E920 (not to be confused with cystine numbered E921!).
Who discovered the amino acid?
A general boom in the study of all types of amino acids began at the end of the 19th century. In organic chemistry during this period they occupied first place in the interest of scientists. The amino acid was discovered by the German scientist O. Bauman while studying sulfur-containing components.
In 1884, the scientist described how cysteine is formed by treating cystine with tin and hydrochloric acid. However, the formula and structure of the new substance were established only in 1903 by Erlenmeyer, another native of the German school of chemistry. Together with Bauman, Merner studied L-cysteine - he was able to obtain the substance from the horns of cattle.
General characteristics of cysteine
L-cysteine is a non-essential amino acid, under the influence of which the body produces the most important substances:
- taurine is essential for the functioning of the central nervous system, controls blood pressure and protects eye health. Additionally, it is responsible for the elimination of excess fat during active metabolism and promotes muscle growth;
- Glutathione is an important element in the functioning of the immune system, has strong antioxidant properties and affects the functioning of the nervous system. The potential of glutathione is widely used in the fight against premature aging and loss of strength.
Science confirms that it is impossible to maintain glutathione levels in the body without consuming L-cysteine. No other supplements will help in this case.
The amino acid is involved in the production of lymphocytes and is found in human hair. Almost 100% bioavailability and coincidence with cysteine molecules in hair makes the amino acid an important element in the treatment of alopecia of any kind (baldness). L-cysteine in its pure form and in combination with components that improve its absorption increases the diameter of curls and completely stops their loss.
Interesting! Cysteine has many forms in which it is used - ACC, NAC, acetylcysteine, cysteine hydrochloride, N-Acetylcysteine, N-acetyl-B-cysteine, N-acetyl-L-cysteine and acestine.
The substance also participates in the synthesis of glucose in the body, due to which a surge of energy is observed when consumed. Cysteine affects digestion, improving the protection of the mucous membrane and even stimulating the process of its regeneration.
L-cysteine synthesis: natural process and industry
In the human body, the substance is synthesized from methionine, a sulfur-containing amino acid. For the correct course of the reaction, additional trace elements, vitamins and compounds are needed - B6, serine and hydrogen sulfide. Not only a lack of substances, but also liver disease and pathologies of metabolic processes can affect the process and disrupt it.
Important! The amino acid should be taken in combination with vitamin B6 and E, as well as selenium, calcium and sulfur. To protect against overdose of certain microelements, you should consult a doctor before taking it.
In industry, L-cysteine comes in two forms: synthetic and natural. Creating a synthetic substance is more difficult and expensive, but a natural product is made from human hair, animal hair and bird feathers.
Either type of amino acid is considered safe by the US Food and Drug Administration. However, the form used as a dietary supplementE920, does not bring any benefit to the body.
L-cysteine is a yellowish, creamy or white substance with a faint odor and sour taste. It dissolves well in water and contains virtually no impurities. When heated, it turns into cystine; a similar process occurs with prolonged contact with air. In an alkaline environment it completely disintegrates.
Interesting! N-acetyl-L-cysteine has a different formula from L-cysteine and is used to eliminate toxic poisoning from acetaminophen overdose, as well as as a medication for obsessive-compulsive disorder.
Cysteine is found in almost all protein foods: poultry, eggs, ricotta and milk, as well as yogurt. Plant sources can also be distinguished: onions, and, and oats, as well.
Table: foods high in cysteine
Beneficial features
Among the reviews on cysteine, there are mainly opinions related to the effect of the substance on the skin, nails and hair. But the spectrum of application of the amino acid is incomparably wider:
- can reduce the risk of heart attack, strengthens blood vessels and makes them elastic;
- significantly strengthens the immune system, preventing the development of infections, thereby increasing resistance to cancer;
- stimulates muscle recovery and growth, and also burns subcutaneous fat;
- amino acid is necessary for the synthesis of proteins and collagen;
- supports metabolic processes;
- cleanses the body of harmful substances, even heavy metals;
- reduces the activity of inflammatory processes;
- has a positive effect on metabolic processes in the lenses of the eyes.
Instructions for the use of cysteine suggest its use as a means to support an aging body, since the element slows down the aging process and accelerates cell regeneration. Also included in complex therapy for various gastrointestinal diseases.
For a healthy person without serious diseases, L-cysteine helps improve the condition of hair, nails and skin, increases performance and helps fight free radicals in the body.
Cysteine and sports
The antioxidant effect of the amino acid is valued by athletes of various sizes. As well as its ability to activate the growth of muscle mass without attracting harmful substances. L-cysteine is of great benefit for those who are engaged in areas with temperature changes: swimming, biathlon and other winter sports.
The fat-burning and energy properties of cysteine are important for people exposed to increased physical activity in the process of losing weight, working out or gaining muscle mass. A sufficient amount of amino acid significantly improves muscle recovery even after extreme stress. Cysteine is found in many sports supplements, and athletes regularly report significant improvements in performance after consuming such substances.
Cysteine in medicine
The substance is used for the treatment and prevention of diseases:
- destroys mucus in the respiratory tract, is included in the complex therapy of emphysema and bronchitis;
- in the process of treating malignant tumors, it is used to minimize the effects of radiation and chemical therapy;
- is able to accelerate the healing process after any illness by stimulating the production of leukocytes and lymphocytes;
- used in the treatment of severe poisoning by aldehydes, pesticides and lead;
- medications containing cysteine are used to treat cataracts and other ophthalmic pathologies;
- The supplement is also indicated for the fight against arthritis and arthrosis as a powerful anti-inflammatory product;
- used to restore the body after severe frostbite and burns;
- prescribed to people with various pathologies of the cardiovascular system.
The powerful effect of the substance, aimed at combating various toxins, has also found application in the treatment of alcoholism. Cysteine is actively used in the fight against alcohol intoxication, protects the liver by blocking the destructive effects of alcohol metabolism products.
How to take L-cysteine?
Many manufacturers produce supplements, and each of them has their own instructions for using L-cysteine: for hair, immune protection and to maintain the health of an athlete, for medical purposes.
Important! A dose of 7 g of pure L-cysteine is considered critical for health. In most cases, it is enough to take 500-1500 mg of amino acid per day.
For athletes and for medical reasons, the dosage can be increased to 3000 mg per day. To restore hair and prevent hair loss, you need to take 500 mg of L-cysteine and 1500 mg. By the way, you can buy tablets in this dosage - the reviews are good, and the number of orders is impressive.
Drink cysteine capsules with meals, or 1.5 hours after meals. When taking cysteine, you must drink at least 6 glasses of water so that the drug is well absorbed. It is recommended to simultaneously consume vitamin C in an amount of at least 1500 mg per day to avoid the appearance of kidney stones.
Signs of cysteine deficiency and excess
With a lack of amino acids in the body, the following occurs:
- dryness, flaking of the skin, brittle hair and nails;
- cracks that appear on the mucous membranes in different places;
- problems with memory and performance;
- constant depression, apathy;
- colds associated with severely weakened immunity;
- problems in the gastrointestinal tract and heart.
It is somewhat more difficult to suspect an excess of cysteine, since tests will have to be carried out: there is thickening of the blood and problems in the functioning of the small intestine. When cysteine is abused, discomfort develops throughout the body, allergic reactions and irritability appear.
Side effects and contraindications
Strict adherence to the instructions for use of L-cysteine will minimize possible side effects. But you should not self-prescribe the drug in the following situations:
- diabetes mellitus (amino acid reduces the effectiveness of insulin);
- high blood pressure;
- diseases of the thymus gland;
- liver and kidney diseases require consultation with a doctor before using an amino acid supplement;
- pregnancy and breastfeeding;
- increased pressure in the eyeball and cup-shaped cataracts;
- Regular consumption of eggs, wholemeal bread, cereals, onions and garlic along with cysteine in tablet form can lead to a significant overdose.
If too much of the supplement enters the body, nausea and vomiting occur, eating disorders and various types of spasms are possible. Sometimes headaches develop and discomfort appears in the abdominal area.
An allergy to cysteine in increased quantities may occur: rash, swelling of the throat and breathing problems, arrhythmia. It is strongly not recommended to take the supplement if you are intolerant to lactose. Sometimes headaches occur due to the parallel use of various medications.
Often people do not pay attention to changes in the body such as dry and irritated skin, brittle hair, digestive disorders, weak immunity, fatigue and many others. These seemingly unrelated symptoms may be caused by one thing: cysteine deficiency.
Cysteine is an aliphatic sulfur-containing amino acid. This means that the structural formula of the molecule contains no aromatic bonds and contains one sulfur atom.
It is classified as a non-essential amino acid, i.e. Synthesis of cysteine can occur in the human body. However, in some situations the body requires its additional supply. Therefore, it would be more correct to classify this amino acid as conditionally essential. The chemical formula of cysteine is C3H7NO2S. This is one of the few substances that replenish sulfur reserves in the body.
The bulk of cysteine is spent on the formation of taurine and glutathione. Taurine is a substance that supports the healthy functioning of the human nervous system and brain. It also promotes eye health and helps increase muscle size and lose excess weight, if present.
Glutathione is a powerful antioxidant that supports human immunity. It has been proven that the aging process is largely associated with the appearance of glutathione deficiency. Moreover, its level can be restored to the required level only by increasing the consumption of cysteine.
The functions of cysteine are also diverse. It is used in the treatment of many diseases, in sports and the beauty industry. Let's talk about this in more detail later.
California Gold Nutrition, L-Cysteine, AjiPure, 500 mg, 60 Capsules
How is cysteine different from L-cysteine?
You can often see the inscription L-cysteine on medicine packages. How does it differ from “regular” cysteine? The fact is that cysteine is the general name of a chemical substance that can take the form of two isomers: L-cysteine and D-cysteine. Living organisms contain only L-isomers of amino acids, which is why L-cysteine is used for oral administration.
What's the best way to take it?
Cysteine is contained in preparations in various forms: L-cysteine, N-acetylcysteine, cysteine hydrochloride, cysteine dipeptide, acestine. The use of one form or another of this substance depends on the purpose of the drug. Cysteine is also found in food products in the form of a registered additive E920, but this additive, although absolutely harmless, does not have any beneficial properties for the body. In addition, the amino acid is destroyed when heated, so using the supplement in this form becomes absolutely useless.
Indications for use
In medicine, cysteine is used to treat cataracts in the early stages, as well as to treat pathologies caused by a lack of vitamins. Its use makes it possible to facilitate the recovery of patients after various operations or severe injuries. Being a strong antioxidant, cysteine allows cancer patients to tolerate chemical therapy with fewer negative consequences, and also helps remove various toxins that pollute the body, which is useful in the treatment of alcohol addiction and related diseases of the liver and other organs.
Cysteine has a beneficial effect on the health of hair and nails, so it is widely used in cosmetology. It increases the regeneration of skin cells and helps slow down aging.
This amino acid is most actively used in sports. L-cysteine is a popular sports nutrition supplement. It promotes increased muscle growth and allows for faster recovery after heavy exercise.
How quickly does the effect of taking cysteine appear?
L-cysteine is an easily absorbed amino acid by the body. It is easily absorbed by the stomach when taken orally, after which cysteine biochemically breaks down into various derivatives: taurine, glutathione, chondroitinsulfuric acid and some other substances. For these processes to occur, cysteine is oxidized in the body. The benefits of taking the amino acid have been clinically proven, and the effect begins immediately after it enters the stomach. The appearance of the effect of the intake is accelerated by additional consumption of selenium and vitamin C.
What role does it play in sports and bodybuilding?
Cysteine is essential for maintaining the shape of athletes and weightlifters. During training, the consumption of cysteine significantly exceeds its production by the body itself, therefore, to increase the effectiveness of exercise and build muscle, it is necessary to consume cysteine in foods and preparations.
Food sources of L-cysteine:
- soy protein;
- poultry, pork;
- eggs;
- milk and products of its processing;
- vegetables (onions, garlic, broccoli);
- peas and other legumes.
Cysteine catabolism releases taurine and glutathione, which allow the athlete to easily recover from physical activity, stabilize blood pressure, accelerate muscle growth and fat loss. The antioxidant effect of the amino acid normalizes the functioning of the digestive system, which prevents the accumulation of excess in the body and promotes fat burning.
Bluebonnet Nutrition, L-Cysteine, 500 mg, 60 Veggie Caps
How to take when playing sports?
Athletes are recommended to consume up to 3000 mg of pure cysteine per day. It should be consumed during a meal or an hour and a half after a meal. When taking cysteine supplements, you should increase your usual water intake.
Effect on the human body
Cysteine is used not only in the treatment of diseases, but also to maintain general human health. At the same time, it affects the body of men and women differently. Let's discuss this in more detail.
Impact on men's health
Taking supplements containing N-acetylcysteine increases sperm motility, which helps improve male fertility. The use of L-cysteine together with selenium increases the viscosity of seminal fluid, which facilitates easier fertilization of the egg and pregnancy of the partner. In some cases, we can even talk about a complete cure of certain types of infertility in men.
The use of cysteine can also solve problems with potency. The amino acid affects the erectile function of men through its participation in the production of nitric oxide. Nitric oxide has a relaxing effect on the walls of blood vessels, which helps a man develop a persistent erection.
Should women take it?
Eating supplements containing L-cysteine will not be superfluous for women either. In addition to its use in medicine, the amino acid is actively used in cosmetology. It will improve the condition and appearance of skin, nails and hair. Cysteine breakdown products help slow down the aging process and prolong the youth of the female body.
For hair and skin
L-cysteine is a component of keratin, the protein that makes up our skin, hair and nails. A lack of amino acids can have a detrimental effect on their condition and appearance. Taking medications containing this amino acid will strengthen your hair, make it less brittle, and give it a beautiful and healthy appearance.
The use of cysteine will help restore and strengthen hair after perm, coloring and other negative effects of chemicals. The transformation of your skin will also not go unnoticed - it will become firmer and more elastic, dryness will decrease, and wrinkles will be reduced. As a result, you will experience a significant skin rejuvenation effect.
Source Naturals, L-Cysteine 100 g
Side effects
Side effects when taking cysteine are extremely rare and, if they occur, do not cause serious harm to the body. They are usually caused by not drinking enough water or taking an overdose of the drug.
When using L-cysteine, remember that we consume cysteine in food daily. When taking medications containing cysteine, you should be careful when eating foods that contain large amounts of this amino acid. This is especially true for chicken eggs, baked goods made from wholemeal flour, garlic and onions.
An overdose of cysteine can cause headaches, nausea, and digestive disorders. Taking 7 grams of cysteine per day is hazardous to health. This dose can cause serious damage to the body. Instructions for use of the amino acid recommend using it in a volume of 500 to 1500 mg per day.
Contraindications for use
Like all drugs, cysteine has contraindications. Its use is contraindicated in:
- diabetes mellitus;
- hypertension;
- pregnancy and lactation;
- presence of cup-shaped cataracts;
- increased arterial and/or intraocular pressure.
Solgar, L-Cysteine, 500 mg, 90 Capsules
It is semi-essential, meaning it can be synthesized in the human body. The thiol side chain of cysteine is often involved in enzymatic reactions, acting as a nucleophile. The thiol undergoes oxidation, resulting in the formation of the disulfide derivative cystine, which performs important structural functions in many proteins. As a dietary supplement, cysteine is designated E920.
Cysteine in food
Although cysteine is classified as a nonessential amino acid, in rare cases it may be vital for infants, the elderly and those with certain metabolic diseases or people suffering from malabsorption syndrome. Under normal physiological conditions, if there is sufficient quantity available, cysteine can be synthesized in the human body. Cysteine is catabolized in the gastrointestinal tract and blood plasma. Unlike cysteine, cystine safely passes through the gastrointestinal tract and blood plasma and, before entering the cell, is rapidly divided into two cysteine molecules. Cysteine is found in most high protein foods. Animal sources: pork, sausage, chicken, turkey, duck, meat, eggs, milk, whey protein, ricotta, cottage cheese, yogurt. Plant sources: red peppers, garlic, onions, broccoli, Brussels sprouts, oats, muesli, wheat germ, sprouted lentils. Like others, cysteine is an amphoteric compound.
Industrial sources
In industry, L-cysteine is obtained mainly through the hydrolysis of bird feathers or human hair. In addition, more expensive synthetic L-cysteine is produced, which is suitable for Jewish kosher and Muslim halal rules. The synthetic production of L-cysteine involves fermentation using E. coli mutants. Degussa proposed a production method that uses substituted thiazolines. L-cysteine is produced by hydrolysis of racemic 2-amino-delta-2-thiazoline-4-carboxylic acid using Pseudomonas thiazolinophilum.
Cysteine biosynthesis
In animals, cysteine biosynthesis begins with. Sulfur is a derivative that is converted to homocysteine via the intermediate S-adenosylmethionine. Homocysteine and serine are then combined by cystathionine beta synthase to form the asymmetric thioester cystathionine. The enzyme cystathionine gamma lyase converts cystathionine to cysteine and alpha-ketobutyrate. In plants and bacteria, the biosynthesis of cysteine begins with, which is converted to O-acetylserine by the enzyme transanthelase. The enzyme O-acetylserine (thiol) lyase, using sulfide sources, converts this ester to cysteine, releasing acetic acid.
Biological functions of cysteine
The cysteine thiol group is nucleophilic and is easily oxidized. Its reactivity increases upon ionization of the thiol, and cysteine residues in proteins have pKa values close to neutral. Because of its high reactivity, the thiol group of cysteine has numerous biological functions.
Precursor to the antioxidant glutathione
Due to the ability of thiols to engage in redox reactions, cysteine has antioxidant properties. The antioxidant properties of cysteine are typically expressed as a tripeptide, which is found in humans and other organisms. The systemic availability of oral glutathione (GSH) is negligible, so it must be synthesized from its constituent amino acids, cysteine, and glutamic acid. Glutamic acid and glycine are found in most foods that make up the Western diet, but Westerners may still experience some cysteine deficiency.
Precursor to iron-sulfur clusters
Cysteine is an important source of sulfide in human metabolism. Iron and sulfur sulfide clusters in nitrogenase are extracted from cysteine, which is converted to .
Metal ion binding
In addition to iron-sulfur proteins, there are many other metal cofactors in enzymes associated with the thiolate substituent of cysteinyl residues. Examples include zinc in zinc fingers and alcohol dehydrogenase, copper in blue copper proteins, iron in cytochrome P450, and nickel in hydrogenase. The thiol group also has a high affinity for heavy metals, so that cysteine-containing proteins such as metallothionein are able to bind metals such as mercury, lead and cadmium.
Roles in protein structure
During translation of messenger RNA molecules to produce polypeptides, cysteine is encoded by the codons UGU and UGC. Cysteine is traditionally considered a hydrophilic amino acid, based mainly on the chemical parallels between the thiol group and the hydroxyl groups on the side chain of other polar amino acids. However, the cysteine side chain has been shown to stabilize hydrophobic interactions in micelles to a greater extent than the nonpolar amino acid and polar amino acid side chains. In a statistical analysis measuring the frequency of occurrence of amino acids in different environments in the chemical structure of proteins, free cysteine residues were associated with hydrophobic regions of proteins. Their hydrophobic tendency is equivalent to known non-polar ones such as methionine and tyrosine, and much greater than that of known polar amino acids such as serine and threonine. When determining hydrophobicity values, dividing into the most hydrophobic or the most hydrophilic, cysteine is classified as hydrophobic. Such methods rely on procedures that do not interfere with the tendency of cysteine to form disulfide bonds in proteins, so cysteine is considered a hydrophobic amino acid, although it is sometimes also classified as a low-polar or polar amino acid. While free cysteine residues occur in proteins, most are covalently linked to other cysteine residues, forming disulfide bonds. Disulfide bonds play an important role in the folding and stability of some proteins, especially proteins secreted in the extracellular environment. Since most cellular compartments are a reducing environment, disulfide bonds in the cytosol are usually unstable, but there are some exceptions. Disulfide bonds in proteins are formed by oxidation of thiol groups of cysteine residues. Another sulfur-containing amino acid, methionine, cannot form disulfide bonds. More aggressive oxidizing agents convert cysteine into the corresponding sulfinic and sulfonic acids. Cysteine residues play an important role by forming cross-links between proteins, which increases protein rigidity and also creates proteolytic resistance (since protein export is an expensive procedure, minimizing it whenever possible is encouraged). Inside the cell, disulfide bridges between cysteine residues in the polypeptide maintain the tertiary structure of the protein. Insulin is an example of a protein that has cystine cross-links, where two separate peptide chains are connected by a pair of disulfide bonds. Protein disulfide isomerases catalyze the corresponding formation of disulfide bonds; the cell transfers dehydroascorbic acid to the endoplasmic reticulum, which oxidizes the environment. In this environment, cysteine is oxidized to cystine and no longer functions as a nucleophile. In addition to oxidation to cystine, cysteine is involved in numerous post-translational modifications. The nucleophilic thiol group allows the cysteine to combine with other groups, such as prenylation. Ubiquitin ligases transfer ubiquitin to the side chain, proteins and caspases, which carry out proteolysis in the apoptotic cycle. Inteins often function via the catalytic cysteine. Their functioning is usually limited to the intracellular reducing environment, where cysteine is not oxidized to cystine.
Uses of cysteine
Cysteine, mainly the L-enantiomer, is a starting material in the food, pharmaceutical and medical industries. Cysteine is often used to create odors. For example, as a result of the interaction of cysteine with sugar during the Maillard reaction, you can smell a distinct smell of meat. L-cysteine is also used as a cooking aid for baking. In Asia, cysteine is used as a hair perm because it can break down the disulfide bonds of hair keratin. Cysteine is very widely used in studies of the structure and dynamics of biomolecules. Maleimides are selectively added to cysteine by covalent Michael addition. Cysteine is also widely used in EPR (electron paramagnetic resonance) or paramagnetic relaxation enhanced NMR (nuclear magnetic resonance) spin labeling. In a report published in 1994 by five leading cigarette companies, cysteine was described as "one of 599 cigarette additives." As with most cigarette additives, the specific purpose for its inclusion is unknown. It may be explained, for example, that it acts as an expectorant, as smoking increases mucus production in the lungs, and may also increase levels of a beneficial antioxidant (which is reduced in smokers).
Sheep breeding
Cysteine is necessary for sheep to produce wool: it is an essential amino acid that sheep obtain as food from grass. As a consequence, sheep's wool production stops during droughts, but transgenic sheep have recently been developed that can produce their own cysteine.
Reducing the toxic effects of alcohol
Cysteine has been proposed as a preventative or even antidote to some of the negative effects of alcohol, including liver damage and hangovers. It counteracts the toxic effects of acetaldehyde, a major byproduct of alcohol metabolism and is responsible for most of the negative effects and long-term damage associated with alcohol consumption (but does not reverse the immediate effects of intoxication). Cysteine supports the next step in metabolism, which converts acetaldehyde into the relatively harmless acetic acid. In a rat study, test animals were given a semi-lethal dose of acetaldehyde. 80% of rats given cysteine survived. The animals that received cysteine along with thiamine survived, every single one of them. There is no direct evidence yet of the effectiveness of cysteine in people who drink alcohol regularly but do not abuse it.
N-acetylcysteine
N-acetyl-L-cysteine (NAC) is a cysteine derivative in which an acetyl group is attached to a nitrogen atom. This compound is sold as a dietary supplement and is used as an antidote for acetaminophen overdose and obsessive-compulsive disorders such as trichotillomania.
Cysteine is a sulfur-containing amino acid. According to some sources, it belongs to the so-called conditionally irreplaceable.
This means that under normal conditions the body is able to independently provide itself with this substance, meanwhile, there are cases when a person is forced to replenish amino acid reserves from the outside. One of the factors requiring additional “suppliers” of cysteine is intense physical activity, stress and illness.
general characteristics
In the human body, cysteine is used to produce taurine and glutathione. Taurine is important as a substance that plays a key role for the adequate functioning of the central nervous system. It also helps control blood pressure, maintains eye health, helps build muscle and burn excess fat.
Glutathione is essential for the functioning of the immune system, as it is powerful and also protects the nervous system from damage. By the way, researchers are increasingly linking early aging and loss of strength to glutathione deficiency. At the same time, it has already been proven that the consumption of dietary supplements is not able to restore the required level of glutathione in the body. Maintaining adequate concentration of the substance is possible only in the presence of cysteine.
Cysteine, a substance with the formula C3H7NO2S, in turn, is necessary for maintaining glutathione concentrations, as well as for the functioning of muscle tissue. This amino acid plays an important role in the production of T cells (lymphocytes) and strengthening the immune system. This substance is also a component of human hair. And as experiments have shown, this element is capable of increasing the diameter of hairs. In addition, it is part of insulin, and, if necessary, can be converted into glucose, thus saturating the body with additional energy.
The beneficial effects of cysteine are also felt by the gastrointestinal tract. Since some medications (for example, aspirin) damage the gastric mucosa, this useful component protects the organ cavity and restores the mucous layer.
In the body, cysteine is produced from another sulfur-containing amino acid, methionine. The process of converting methionine into cysteine is complex, multi-step and requires the presence of certain enzymes and vitamins. A deficiency of any of the necessary components causes a “system failure.” The conversion of methionine to cysteine can be disrupted due to various diseases.
Also, the “raw materials” for this amino acid are vitamin B6 and serine, and the body uses hydrogen sulfide to form the sulfur-containing component cysteine.
The worst effects on amino acid production are liver diseases and metabolic disorders. In the body of newborns this process does not occur at all. But nature made sure that babies get everything they need from their mother’s milk while their body is being rebuilt in a new way.
Benefits for the body
Cysteine has found its use in chronic obstructive pulmonary disease, and some proponents of the amino acid treatment say it is effective in preventing colon cancer. Meanwhile, it is known that the amino acid promotes detoxification of the body (after drinking alcohol and smoking or acetaminophen overdoses) and increases athletic endurance. There is also an opinion that this substance can protect a person from the negative effects of radiation.
Cysteine and...
…diabetes
The results of a study conducted in 2008 on rats showed the effect of cysteine on the diabetic body. In laboratory animals, after taking the element, blood sugar levels significantly decreased and insulin resistance increased. In addition, it turned out that it inhibits inflammation of blood vessels, which are often key factors in the occurrence of cardiac diseases associated with diabetes.
…colitis
That same year, Dutch scientists analyzed the effect of cysteine on inflamed intestines. It turned out that the amino acid can ease colitis. True, this experiment was also carried out on animals. This time they chose blue as the test subjects.
...free radicals
Cysteine, affecting the human body, prevents the production of free radicals. In 10 men who took part in a 7-day experiment, the body's antioxidant capacity increased and the production of free radicals decreased.
In alternative medicine, it is used as a natural remedy for:
- angina pectoris;
- cardiovascular diseases;
- chronic bronchitis;
- diabetes;
- flu;
- inflammation;
- intestinal diseases;
- osteoarthritis.
Daily amino acid requirement
The consumption rates of cysteine in the form of dietary supplements are indicated in the instructions for use. To avoid negative consequences, it is important to adhere to these recommendations. Additionally, when consuming this amino acid, it is important to ensure adequate intake.
But some forms of cysteine can be toxic to the body. Researchers say that a person tolerates the amino acid well in doses of 2500-3000 mg per day. But consuming more than 7 g of the substance per day can have a toxic effect and cause unpleasant side effects.
Who needs it most
Cysteine is equally necessary for all people, but some, as they say, need it more. In particular, severe stress and increased physical activity may require the body to require a little more amino acid than usual. People with weakened immune systems also need dietary supplements and foods rich in amino acids. will help optimize body functions and increase resistance to disease. Cysteine deficiency is especially acute for people with HIV/AIDS. You can also increase your daily amino acid intake for people with rheumatoid arthritis, chronic cardiac diseases, diseases of the respiratory system, and cataracts (initial stage).
Who should not abuse it?
In some cases, the consumption of cysteine should be treated with extreme caution. This applies to patients with diabetes, since the component affects the effectiveness of insulin. It is also recommended to take cysteine a little less than usual for hypertension, problems with the thymus gland, as well as for pregnant and nursing mothers. People whose diet contains cereals, eggs, baked goods, as well as garlic or onions also do not need additional cysteine-containing drugs.
Side effects
If side effects occur while taking cysteine, as a rule, they do not cause extreme damage to the body. The most common: stomach upset, nausea, vomiting, diarrhea, abdominal cramps, headaches and gastrointestinal discomfort. Typically, side effects occur due to insufficient water intake.
Cautions
Some individuals are diagnosed with cysteine intolerance, then allergic reactions occur against the background of a dietary supplement containing the amino acid. In such cases, the body reacts to cysteine by producing excessive amounts of the hormone homocysteine (released by the body in response to toxins). The allergy is manifested by a skin rash, swelling of the throat and face, difficulty breathing, arrhythmia, and the person needs emergency medical care.
Combination with other substances
Today, science knows little about how long-term use of cysteine affects the body’s functioning. There are some concerns about combining the amino acid with other substances.
Supplements containing cysteine may interact negatively with certain medications. For example, there is information that the component blocks the work of drugs against sore throat, some inhibitors, and medications that act as enzymes. Thus, it is recommended to take cysteine with extreme caution when taking medications that suppress the immune system (for example, prednisolone). It is also not recommended for nursing mothers and pregnant women to get carried away with dietary supplements.
Lack of the substance affects the health of nails and hair, dries out the skin, provokes cracks in the mucous membranes of the body, and causes depression. In addition, amino acid deficiency is fraught with diseases of the cardiovascular system, digestive disorders, weakened immunity, and deterioration of brain function.
Food sources
Like others, cysteine is present in many high-protein foods. This includes all meat and dairy products, eggs, poultry, beans, buckwheat, fish, sesame seeds, nuts and seeds. Small amounts of cysteine are found in broccoli, Brussels sprouts, red and yellow peppers, garlic and onions. But high temperature during cooking deprives the component of biological activity. Meanwhile, you shouldn’t place high hopes on raw food either. Stomach acid and intestinal bacteria partially prevent cysteine from entering the blood.
The body most easily absorbs the component from cow's milk whey. This product contains the amino acid in the form of cystine - a block of 2 cysteine molecules. Once in the cells of the body, cystine again breaks down into 2 cysteine molecules. Pasteurizing milk and repeatedly heating it breaks down these blocks. For this reason, milk from supermarkets cannot serve as a source of amino acids.
Amino acid in industry
Cysteine is actively used in the food industry as an additive E920. However, in this form it is not able to benefit the body. There is an opinion that in the form of a food additive it causes kidney and cardiovascular diseases.
Supplements containing cysteine are of synthetic and natural origin. The synthetic version is the result of the chemical industry. It is cheaper to produce amino acids of natural origin. Hair, wool and feathers are used for these purposes. They are known to be rich in keratin, which in turn contains cysteine. As a result of lengthy manipulations, the breakdown product in the form of an amino acid is extracted from the raw material.
Our health and well-being directly depends on the normal function of all systems. Dietary supplements with valuable components help to recover from illnesses and also compensate for the lack of necessary substances. It is important not only to prevent such conditions, but also to actively treat them using new modern biological products.
The discovery of this amino acid occurred at the end of the 19th century by Bauman, but the exact formula was derived by the scientist Erlenmeyer almost 20 years later. Another scientist, Merner, synthesized and studied its properties. To do this, he used tissue from cattle horns. L-cysteine is now sold in the form of dietary supplements; indications for use and possible contraindications are discussed below.
What is L-cysteine
L-cysteine is a nonessential sulfur-containing amino acid produced in mammals from serine and vitamin B6. Her role is little known and most of us are not even aware of its significance. Cysteine, meanwhile, is responsible for the normal production of substances such as glutathione and taurine. They perform many functions in our body, in particular - ensuring normal functioning of the immune system, delaying aging and timely renewal of tissues at the cellular level. Taurine is important for eye health and the formation of nerve fibers. Glutathione ensures normal blood pressure levels and is involved in the formation of the most important blood cells - lymphocytes.
Physical characteristics of L-cysteine:
- Colorless crystals.
- Sulfur-containing amino acid.
- It dissolves well in water and does not form sediment.
- Upon contact with air or heating, it transforms into cystine.
In the complex, L-cysteine provides a good detoxifying effect and helps reduce the negative effects of heavy metals and radioactive radiation on our body. When taking amino acid, selenium and vitamin C supplements simultaneously, the antioxidant properties increase significantly. A good positive effect when taking this amino acid is observed in smokers and people who regularly drink alcohol. The drug helps protect brain and liver cells, which are primarily exposed to toxic effects with this lifestyle.
Its effect on the human body
The benefits of L-cysteine for our health are difficult to overestimate. The first signs of a lack of this substance are displayed directly externally. Deterioration of skin and hair condition, brittle nails and rapid aging - all this may indicate amino acid deficiency. Problems in internal systems are less noticeable, but can still lead to serious consequences.
What is the danger of cysteine deficiency?
- Increased fragility of hair and nails.
- Premature skin aging.
- Decreased vitality, loss of strength.
- Physical exhaustion of the body, slowing down regeneration processes.
- Depressed state, depression and constant fatigue.
Cysteine is a natural antioxidant that allows you to quickly remove harmful substances from the body. It even gets rid of heavy metals and radioactive damage, so it is extremely important for residents of contaminated areas to regularly undergo such a course of intoxication.
What products contain
Cysteine is found in large quantities in our usual foods. This is mainly pork meat, chicken fillet, and red fish pulp. In smaller quantities, this amino acid can be found in sunflower seeds, walnuts, egg yolk, milk, greens, rice and soy. On an industrial scale, cysteine is produced by hydrolysis from protein keratin-containing waste and synthetically. The food supplement cysteine is labeled as E920 (L-cysteine - E921). It is used in the food industry, in particular for bleaching wheat flour. In pharmacology, L-cysteine preparations are used in the complex treatment of chronic diseases, as well as for maintenance and rehabilitation therapy after illnesses.
Beneficial features
L-cysteine is the so-called L-isomer of the amino acid cysteine. It is in the most easily digestible form; under the influence of gastric acid, it is quickly broken down into taurine, glutathione and other beneficial substances. They have a diverse effect on our body, ensuring the stable operation of almost all internal systems.
What are the benefits of L-cysteine:
- Normalizes blood pressure, improves vascular elasticity.
- Accelerates metabolic processes, promotes weight loss and muscle gain during physical activity.
- Improves the functioning of the nervous system.
- Helps solve the problem of hair loss and is used in the fight against alopecia.
- Helps improve vision and is used in the treatment of eye diseases.
- Stimulates the regeneration of the gastrointestinal mucosa, improves digestive function.
- Helps with intoxication of the body, removes harmful substances and reduces the negative effects of radiation.
- Used to prevent cardiovascular diseases.
- Provides protection for liver cells during alcohol consumption or toxic damage.
A course of taking L-cysteine capsules allows you to increase your vitality and provide an influx of additional strength and energy. In complex therapy, it is often used to support the body after illnesses, including after a course of chemotherapy. Substances formed during the breakdown of the amino acid cysteine are involved in the synthesis of collagen and protein, and ensure the rapid breakdown of glucose. Together with other supplements, L-cysteine is important in maintenance therapy, helps prolong youth and adds energy. The product is widely used in medicine, sports nutrition and cosmetic purposes.
L-cysteine for hair
This amino acid is most beneficial for beauty. A lack of cysteine can lead to brittle nails and hair, while sufficient consumption of it significantly improves their condition. In addition, L-cysteine ensures a thickening of the protective layer of the hair shaft, providing additional volume and strength to weakened strands. All this is possible due to the identical composition of amino acid molecules with the structure of hair, as well as stimulating the production of collagen protein in the body naturally.
How to take, instructions
The capsules of the drug contain 500 mg of amino acid. The maximum permissible dosage is no more than 7 g of pure cysteine per day. For the treatment and prevention of diseases, improvement of general tone, it is enough to calculate the intake of the drug in a volume of 500 to 1500 mg/day.
Capsules are taken at the same time, preferably during meals, with a large volume of water. For intense physical activity (athletes) or patients who have suffered severe poisoning, the dosage can be increased to 3000 mg/day. The intake is often combined with the use of vitamin C, which promotes detoxifying effects and improves the absorption of the product.
Contraindications and side effects
The use of L-cysteine capsules should be discussed with your doctor. Absolute contraindications are diabetes mellitus and cystinuria - a rare genetic disease in which there is a tendency to form cystine stones in internal organs.
A relative contraindication is pregnancy and breastfeeding. Any medications at this time must be used strictly according to indications, monitoring the patient’s condition. You should also definitely consult a doctor if you have already diagnosed kidney and liver problems. Possible negative consequences may include individual intolerance to the drug, as well as digestive disorders associated with insufficient absorption of sulfur-containing amino acids.
