Functions of galactose. Galactose is: definition, properties, functions and role in the body. The need for galactose is increasing
The baby receives a large amount of this substance with mother's milk. Over the years, the need for galactose decreases, but still remains one of the main ones.
Galactose is one of the main sources of energy for the body. It is a simple milk sugar. It is necessary for the full functioning of our body, and is also used in medicine and microbiology.
Foods rich in galactose:
General characteristics of galactose
Galactose is a monosaccharide that is very common in nature. It is close in composition to glucose, only slightly differs from it in its atomic structure.
Galactose is found in some microorganisms, in almost all products of plant and animal origin. Its highest content is found in lactose.
There are two types of galactose: L and D. The first, in the form of a proportion of polysaccharides, was found in red algae. The second is much more common, it can be found in many organisms as part of various substances - glycosides, oligosaccharides, in a number of bacterial and plant polysaccharides, pectin substances, gums. Oxidized, galactose creates galacturonic and galactonic acids.
Galactose is used in medicine as a contrast agent for ultrasound, as well as in microbiology to determine the type of microorganisms.
daily requirement for galactose
The galactose level should remain at 5 mg/dL in the blood. You can easily get the daily norm of galactose if you eat dairy products or celery. Despite the fact that galactose is very common in foods, it simply does not exist in its pure form in organisms or foods. That is, galactose in products should be looked for by the presence of lactose.
The need for galactose increases:
- in infants;
- during lactation (galactose is a necessary component for the synthesis of lactose);
- with increased physical activity;
- with increased mental stress;
- with constant fatigue.
The need for galactose decreases:
- if you are allergic to galactose or dairy products;
- with intestinal diseases;
- with inflammatory diseases of the female genital organs;
- with heart failure;
- in violation of assimilation - galactosemia.
Digestibility of galactose
Galactose is quickly absorbed by the body. As a monosaccharide, galactose is the fastest source of energy.
In order for the body to absorb galactose, it enters the liver and is converted into glucose. As with any carbohydrate, the absorption rate of galactose is very high.
Malabsorption of galactose is called galactosemia and is a serious disease that is inherited. The essence of galactosemia is that galactose cannot be converted into glucose due to the lack of an enzyme.
As a result, galactose accumulates in body tissues and blood. Its toxic action destroys the lens in the eye, the liver and the central nervous system. With untimely treatment, the disease can be fatal, as it causes cirrhosis of the liver.
Galactosemia is treated mainly with a strict diet, in which the patient generally does not consume foods that contain galactose or lactose.
Useful properties of galactose and its effect on the body
Galactose is actively involved in the creation of cell walls, and also helps tissues to be more elastic. It is part of the lipids of the brain, blood and connective tissue.
Galactose is indispensable for the brain and nervous system. A normalized level of galactose prevents the development of dementias, as well as nervous disorders. Reduces the risk of developing Alzheimer's disease.
It also has a beneficial effect on the functioning of the organs of the gastrointestinal tract.
Galactose takes part in the creation of hemicellulose, which is necessary for the creation of cell walls.
Prevents the development of certain diseases of the nervous system.
Interaction with other elements
Galactose reacts with glucose to create the disaccharide you've probably heard a lot about: lactose. Easily soluble in water.
Signs of a lack of galactose in the body
Signs of a lack of galactose are similar to a lack of carbohydrates - a person gets tired quickly and very much, feels that it is difficult for him to concentrate. He is easily depressed and unable to develop physically.
Galactose, like glucose, is a source of energy for the body, so its level should always be normal.
Signs of excess galactose in the body
- disruption of the nervous system and hyperactivity;
- disruption of the liver;
- destruction of the eye lens.
Factors affecting the content of galactose in the body
Galactose enters the body with food, and is also formed in the intestine by hydrolysis from lactose.
The main factor affecting the content of galactose is the presence of a special enzyme that converts galactose into a substance (glucose-1-phosphate) that can be absorbed by humans. In the absence of this enzyme, an imbalance of galactose in the body begins, which leads to the development of diseases.
Regular consumption of foods containing galactose is also very important. For a healthy person, insufficient consumption of appropriate foods leads to developmental disorders, both physical and mental.
Galactose for beauty and health
Galactose is very important for the human body as a source of energy. It allows him to grow and develop, stay alert and energetic.
Galactose is important for the physical development of the body, so athletes actively consume foods and preparations containing this substance.
The metabolism of fructose and galactose includes ways of using them for the synthesis of other substances (heteropolysaccharides, lactose, etc.) and participation in the energy supply of the body. In the latter case, fructose and galactose are converted in the liver either into glucose or into intermediate products of its metabolism. Thus, as a result, fructose and galactose, along with glucose, can be oxidized to CO 2 and H 2 O or used for the synthesis of glycogen and triacylglycerols.
The reason for the violation of the metabolism of fructose and galactose may be a defect in the enzymes that catalyze the intermediate reactions of their metabolism. These disorders are relatively rare, but can be quite dangerous, since the accumulated intermediate metabolites of fructose and galactose are toxic.
A. Fructose metabolism
A significant amount of fructose, formed during the breakdown of sucrose, before entering the portal vein system, is converted into glucose already in the intestinal cells. Another part of the fructose is absorbed with the help of a carrier protein, i.e. through facilitated diffusion.
Fructose metabolism (Figure 7-69) begins with a phosphorylation reaction (reaction 1) catalyzed by fructokinase to form fructose-1-phosphate. The enzyme is found in the liver, as well as in the kidneys and intestines. This enzyme has absolute specificity, therefore, unlike glkzhokinase, insulin does not affect its activity. The latter circumstance explains why the level of excretion of fructose in the urine in patients with diabetes mellitus and healthy people does not differ. Fructose-1-phosphate cannot be converted to fructose-6-phosphate due to the lack of the corresponding enzyme. Instead, fructose-1-phosphate is further cleaved by fructose-1-phosphate aldolase (aldolase B) into glyceraldehyde and dihydroxyacetone-3-phosphate (reaction 2). The latter is an intermediate product of glycolysis and is formed during the reaction catalyzed by fructose-1,6-bisphosphophosphate aldolase (aldolase A). Glyceraldehyde can be included in glycolysis after its phosphorylation with the participation of ATP (reaction 3). Two molecules of triose phosphates either decompose along the glycolytic pathway or condense to form fructose-1,6-bisphosphate and then participate in gluconeogenesis (reactions 8, 7, 5, 9). Fructose in the liver is mainly included in the second pathway. Part of dihydroxyacetone-3-phosphate can be reduced to glycerol-3-phosphate and participate in the synthesis of triacylglycerols.
It should be noted that the incorporation of fructose into metabolism via fructose-1-phosphate bypasses the step catalyzed by phosphofructokinase (reaction 6), which is the point of the metabolic pathway.
Rice. 7-69. fructose metabolism. a - conversion of fructose into dihydroxyacetone-3-phosphate and glyceraldehyde-3-phosphate; b - the way of including fructose in glycolysis and gluconeogenesis; c - the way of including fructose in the synthesis of glycogen.
control the rate of glucose catabolism. This circumstance can explain why an increase in the amount of fructose accelerates the processes in the liver leading to the synthesis of fatty acids, as well as their esterification with the formation of triacylglycerols.
Since all monosaccharides (fructose, galactose, mannose, etc.) that come with food are absorbed in the intestines, the body faces the task of converting the resulting hexoses into glucose for its further use in metabolic reactions - occurs sugar conversion. With a defect in the corresponding enzymes, the accumulation of monosaccharides in the blood occurs - galactosemia and fructosemia.
Conversion of monosugars
The purpose of this process is to create only one substrate for metabolic reactions, namely α-D-glucose, which saves resources, does not form many enzymes for each type of monosaccharide. Reactions of formation of free glucose occur in the epithelium intestines and mainly in hepatocytes.
In children, some time after birth, even with hypoglycemia, there is a relative excess of other monosaccharides in the blood, for example, fructose and galactose, which is usually associated with functional immaturity of the liver.
Transformation of galactose
Galactose first undergoes phosphorylation at the 1st carbon atom. A distinctive feature is the conversion to glucose not directly, but through the synthesis of UDP-galactose from galactose-1-phosphate. The source of UMF is UDP-glucose present in the cell. The formed UDP-galactose subsequently isomerizes into UDP-glucose, and then its fate is different.
She can:
- participate in the UMP transfer reaction to galactose-1-phosphate,
- converted into free glucose and released into the blood,
- go for glycogen synthesis.
The biochemical complication of a seemingly simple epimerization reaction is apparently caused by the synthesis of UDP-galactose from glucose in the mammary gland to obtain lactose in the formation of milk. Galactose is also used in the synthesis of the corresponding hexosamines in heteropolysaccharides.
Disorders of the conversion of galactose
Disorders of galactose metabolism can be caused by a genetic defect in one of the enzymes:
- galactokinase, defect frequency 1:500000,
- galactose-1-phosphate uridyltransferase, defect frequency 1:40000,
- epimerases, defect frequency less than 1:1000000.
The disease that occurs with these disorders is called galactosemia.
Diagnostics . Children refuse to eat. The concentration of galactose in the blood increases to 11.1-16.6 mmol / l (the norm is 0.3-0.5 mmol / l), galactose-1-phosphate appears in the blood. Laboratory criteria also include bilirubinemia, galactosuria, proteinuria, hyperaminoaciduria, and accumulation of glycosylated hemoglobin.
Pathogenesis. Excess galactose is converted to alcohol galactitol(dulcitol) accumulates in the lens and osmotically attracts water here. The salt composition changes, the conformation of the lens proteins is disturbed, which leads to cataract In young age. Cataracts are possible even in the fetuses of mothers with galactosemia who consumed milk during pregnancy.
With a defect in galactose-1-phosphate-uridyl transferase, ATP is constantly consumed for galactose phosphorylation and energy deficiency inhibits the activity of many enzymes, "toxic" acting on neurons, hepatocytes, and nephrocytes. As a result, psychomotor retardation, mental retardation, hepatocyte necrosis and cirrhosis of the liver are possible. In the kidneys and intestines, an excess of galactose and its metabolites inhibits the absorption of amino acids.
Fundamentals of Treatment. Exclusion from the diet of milk and other sources of galactose helps prevent the development of pathological symptoms. However, the preservation of intelligence can only be achieved with early, no later than the first 2 months of life, diagnosis and timely treatment.
In general, the transition of fructose to glucose occurs in two directions. First, fructose is activated by phosphorylation of either the 6th carbon atom with the participation of hexokinase, or the 1st atom with the participation fructokinase.
AT liver both enzymes are present, but hexokinase has a much lower affinity for fructose and this pathway is weakly expressed in it. The fructose-6-phosphate formed by it is further isomerized and glucose-6-phosphatase cleaves off the already unnecessary phosphate to produce glucose.
If fructokinase works, then fructose-1-phosphate is formed, under the action of the corresponding aldolase it turns into glyceraldehyde and dihydroxyacetone phosphate. Glyceraldehyde is phosphorylated to glyceraldehyde phosphate and, together with dihydroxyacetone phosphate, they are used in further reactions or used in glycolysis, or in reactions gluconeogenesis converted to fructose-6-phosphate and then to glucose.
feature muscles is an absence fructokinase, so fructose in them immediately turns into fructose-6-phosphate and enters the reactions of glycolysis or glycogen synthesis.
Pathways of fructose metabolism and its conversion to glucose
A feature of fructose metabolism is that the enzyme fructokinase is an insulin independent. As a result, the conversion of fructose into pyruvic acid and acetyl-SCoA going faster than for glucose. This is due to "ignoring" the limiting reaction of glucose metabolism catalyzed by phosphofructokinase. Further metabolism of acetyl-SCoA in this case can lead to excessive formation of fatty acids and triacylglycerols.
Fructose Metabolism Disorders
Essential fructosuria
A genetic defect in fructokinase leads to a benign essential fructosuria proceeding without any negative symptoms.
hereditary fructosuria
The disease is formed due to hereditary autosomal recessive defects in other enzymes of fructose metabolism. Frequency 1:20000.
Defect fructose-1-phosphate aldolase, which is normally present in the liver, intestines and cortex of the kidneys, manifests itself after the introduction of juices and fruits containing fructose into the infant's diet.
Pathogenesis associated with a decrease in glycogen mobilization due to inhibition of glycogen phosphorylase by fructose-1-phosphate and a weakening of gluconeogenesis, tk. the defective enzyme is able to participate in reactions similar to fructose-1,6-diphosphate-aldolase. The disease is manifested by a decrease in the concentration of phosphates in the blood, hyperfructosemia, severe hypoglycemia. There is lethargy, impaired consciousness, renal tubular acidosis.
Diagnosis put on the basis of "incomprehensible" liver disease, hypophosphatemia, hyperuricemia, hypoglycemia and fructosuria. For confirmation, a fructose tolerance test is performed. Treatment includes a diet with restriction of sweets, fruits, vegetables.
Defect fructose-1,6-diphosphatase It manifests itself similarly to the previous one, but not so hard.
general characteristics
It decreases from the first, but still remains one of the main ones.
Galactose is one of the main sources of energy for the body. It is a simple milk sugar. It is necessary for the full functioning of our body, and is also used in medicine and microbiology.
Galactose is a monosaccharide that is very common in nature. It is close in composition to glucose, only slightly differs from it in its atomic structure.
Galactose is found in some microorganisms, in almost all products of plant and animal origin. Its highest content is found in lactose.
There are two types of galactose: L and D. The first, in the form of a proportion of polysaccharides, was found in red algae. The second is much more common, it can be found in many organisms as part of various substances - glycosides, oligosaccharides, in a number of bacterial and plant polysaccharides, pectin substances, gums. Oxidized, galactose creates galacturonic and galactonic acids.
Galactose is used in medicine as a contrast agent for ultrasound, as well as in microbiology to determine the type of microorganisms.
Useful properties of galactose and its effect on the body
Galactose is actively involved in the creation of cell walls, and also helps tissues to be more elastic. It is part of the lipids of the brain, blood and connective tissue.
Galactose is indispensable for the brain and nervous system. A normalized level of galactose prevents the development of dementias, as well as nervous disorders. Reduces the risk of developing Alzheimer's disease.
It also has a beneficial effect on the functioning of the organs of the gastrointestinal tract.
Galactose takes part in the creation of hemicellulose, which is necessary for the creation of cell walls.
Prevents the development of certain diseases of the nervous system.
Foods rich in galactose
The simple carbohydrate galactose is not found in pure form in food. But, combining with glucose, it forms a disaccharide, lactose, which enters our body with dairy products: milk, sour cream, cheese, yogurt, kefir. In the gastrointestinal tract, lactose is broken down into glucose and galactose. Then galactose, once in the blood, is converted in the liver into glucose.
daily requirement for galactose
The galactose level should remain at 5 mg/dL in the blood. You can easily get the daily norm of galactose if you eat dairy products or celery. Despite the fact that galactose is very common in foods, it simply does not exist in its pure form in organisms or foods. That is, galactose in products should be looked for by the presence of lactose.
The need for galactose increases:
- in infants;
- during lactation (galactose is a necessary component for the synthesis of lactose); with increased physical activity;
- with increased mental stress;
- under stress;
- with constant fatigue.
The need for galactose decreases:
- in old age;
- if you are allergic to galactose or dairy products;
- with intestinal diseases;
- with inflammatory diseases of the female genital organs;
- with heart failure;
- in violation of assimilation - galactosemia.
Digestibility of galactose
Galactose is quickly absorbed by the body. As a monosaccharide, galactose is the fastest source of energy.
In order for the body to absorb galactose, it enters the liver and is converted into glucose. As with any carbohydrate, the absorption rate of galactose is very high.
Malabsorption of galactose is called galactosemia and is a serious disease that is inherited. The essence of galactosemia is that galactose cannot be converted into glucose due to the lack of an enzyme.
As a result, galactose accumulates in body tissues and blood. Its toxic action destroys the lens in the eye, the liver and the central nervous system. With untimely treatment, the disease can be fatal, as it causes cirrhosis of the liver.
Galactosemia is treated mainly with a strict diet, in which the patient generally does not consume foods that contain galactose or lactose.
Interaction with other elements
Galactose reacts with glucose to create the disaccharide you've probably heard a lot about: lactose. Easily soluble in water.
Signs of a lack of galactose in the body
Signs of a lack of galactose are similar to a lack of carbohydrates - a person gets tired quickly and very much, feels that it is difficult for him to concentrate. He is easily depressed and unable to develop physically.
Galactose, like glucose, is a source of energy for the body, so its level should always be normal.
Signs of excess galactose in the body
- disruption of the nervous system and hyperactivity;
- disruption of the liver;
- destruction of the eye lens.
Factors affecting the content of galactose in the body
Galactose enters the body with food, and is also formed in the intestine by hydrolysis from lactose.
The main factor affecting the content of galactose is the presence of a special enzyme that converts galactose into a substance (glucose-1-phosphate) that can be absorbed by humans. In the absence of this enzyme, an imbalance of galactose in the body begins, which leads to the development of diseases.
Regular consumption of foods containing galactose is also very important. For a healthy person, insufficient consumption of appropriate foods leads to developmental disorders, both physical and mental.
Galactose for beauty and health
Galactose is very important for the human body as a source of energy. It allows him to grow and develop, stay alert and energetic.
Galactose is important for the physical development of the body, so athletes actively consume foods and preparations containing this substance.
Galactose and cellulite
Cellulite is the deposition of Galactose due to malnutrition in the subcutaneous layers, especially in women, especially on the thighs. Galactose is a breakdown product of lactose (milk sugar). Once in the stomach, milk under the action of hydrochloric acid in the stomach breaks down into Glucose and Galactose. Glucose is the main source of energy, it is absorbed without residue. And Galactose is not absorbed by the human body at all from the moment the child is weaned from the breast, i.e. the gene responsible for the processing and assimilation of Galactose is switched off with weaning. A baby needs galactose as a reserve of additional energy (since the baby does not yet have energy reserves) and, if necessary, the liver of a child who consumes only mother's milk will process it into Glucose.
Features of the appointment of complementary foods for galactosemia
From the age of 4 months, the diet of a patient with galactosemia is expanded due to fruit and berry juices (apple, pear, plum, etc.), starting with 5–10 drops, gradually increasing the volume to 30–50 ml per day, by the end of the year - up to 100 ml.
From 4.5 months, fruit puree is introduced, the amount of which is increased in the same way as with the introduction of juice. The first complementary foods in the form of vegetable puree from natural vegetables or canned fruits and vegetables for baby food without the addition of milk (and not containing legumes) are prescribed from 5 months.
At 5.5 months, a second complementary food is introduced - dairy-free cereals of industrial production based on corn, rice or buckwheat flour. To breed cereals, you must use the specialized mixture that the child receives. Meat complementary foods are introduced into the diet from 6 months.
The advantage is given to specialized children's industrial canned meat products that do not contain milk and its derivatives (rabbit, chicken, beef, turkey, etc.).
Diet therapy for galactosemia
The main treatment for classical galactosemia is diet therapy, which involves a life-long exclusion from the diet of foods containing galactose and lactose. It is necessary to completely exclude from the patient's diet any kind of milk (including women's, cow's, goat's, baby milk formulas, etc.) and all dairy products, and also carefully avoid the use of those products where they can be added (bread, pastries, caramel, sweets, margarines, etc.). It is also forbidden to use low-lactose milk and mixtures.
A number of products of plant origin contain oligosaccharides - galactosides (raffinose, stachyose), animal origin - nucleoproteins, which can be potential sources of galactose.
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"... Galactose (from the Greek root γάλακτ-, "milk") is one of the simple sugars, a monosaccharide from the hexose group. It differs from glucose in the spatial arrangement of the hydrogen and hydroxyl groups at the 4th carbon atom. It is found in animal and plant organisms, including in some microorganisms.It is a part of disaccharides - lactose and lactulose.When oxidized, it forms galactonic, galacturonic and mucic acids.L-galactose is part of the polysaccharides of red algae.D-galactose is widely distributed in nature, is part of oligosaccharides (melibiose , raffinoses, stachyoses), some glycosides, vegetable and bacterial polysaccharides (gums, mucus, galactans, pectins, hemicelluloses), in the body of animals and humans - in the composition of lactose, group-specific polysaccharides, cerebrosides, keratosulfate, etc. In animal and plant tissues D-galactose can be included in glycolysis with the participation of uridine diphosphate-B-glucose-4-epimerase, turning into hl yucose-1-phosphate, which is absorbed. In humans, the hereditary absence of this enzyme leads to an inability to utilize D-galactose from lactose and causes a serious disease - galactosemia ... " [Wikipedia]
"... Galactose (from the Greek word gala, galaktos - milk) is a monosaccharide - a C-4 epimer of glucose, with an identical molecular formula, but with a structural formula different from glucose. Despite the great similarity of glucose and galactose molecules, the transformation of the latter into glucose requires several evolutionarily conserved enzymatic reactions that occur in the cytoplasm of the cell and are known as the Leloir pathway of galactose metabolism.
Galactose is essential for the growth and development of the child's body, as it is a component of the food of an infant, being part of the milk. This monosaccharide is not only a significant source of energy for the cell, but also serves as a necessary plastic material for the formation of glycoproteins, glycolipids and other complex compounds used by the body to form cell membranes, nervous tissue, nerve endings, neuronal myelination processes, etc.
The main source of galactose in humans is food. A large number of foods consumed during the day contain lactose, from which galactose is formed in the intestine as a result of hydrolysis; Many foods contain pure galactose. In humans, galactose can be formed endogenously, the vast majority of it is synthesized during enzymatic reactions between uridine diphosphate glucose (UDP-glucose) and UDP-galactose, as well as during the exchange of glycoproteins and glycolipids.
Violation of galactose metabolism, observed in galactosemia, inevitably leads to disruption of the functioning of many organs and body systems ... "
"... Galactose is formed during the hydrolysis of the disaccharide lactose (milk sugar) in the intestine. In the liver, it is easily converted into glucose. The ability of the liver to carry out this transformation can be used as a functional test for tolerance to galactose ..."
[humbio.com]
"...Most of the ingested galactose goes to the liver, where it is mostly converted to glucose, which can then either be converted to glycogen or used for energy..."
"... Normally, lactose passes through the stomach, and then in the small intestine undergoes hydrolysis through the Leloir metabolic pathway, with the participation of β-galactosidase localized on the plasma membranes of enterocytes. The resulting glucose and galactose are subsequently absorbed. Galactose enters the body in the form of a monosaccharide. .."
"... The metabolism of galactose [in fact, like fructose] is carried out by converting it into glucose, mainly in the liver. The liver has the ability to synthesize glucose from various sugars, such as fructose and galactose, or from other products of intermediate metabolism (lactate, alanine, etc.). )..."
"... In addition to the intake of galactose from food, the human body is able to synthesize a significant amount of de novo galactose from glucose, as well as from a pool of galactose, which is part of glycoproteins and mucopolysaccharides. This process is important for maintaining galactose and its metabolites necessary for the synthesis of galactose-containing glycoproteins On a galactose-restricted diet, endogenous production of galactose ranges from 1.1 to 1.3 g / day ...
[galactose can bind to glucose to synthesize lactose (in breast milk), to lipids to synthesize glycolipids, or to proteins to synthesize glycoproteins]
Human studies have shown that galactose and glucose share a common transport mechanism for intestinal absorption. This transport mechanism has a greater affinity for glucose than for galactose, and this may explain why galactose uptake is inhibited by glucose. When galactose is absorbed along with glucose, serum galactose concentrations are significantly lower than when the same amount of galactose is consumed without glucose. Galactose uptake can also be reduced with leptin and b3-adrenergic receptor agonists..."
"... it should be borne in mind that not all lactic acid bacteria are able to ferment galactose. Accordingly, this also affects the concentration of galactose in the final dairy product. Incomplete fermentation of galactose gives an excess amount of galactose in the product, which is associated with poor quality of the dairy product.
Also, it must be taken into account that not all types of lactose are completely digested in the small intestine, some of them are fermented by the intestinal microbiota, and in people suffering from lactose intolerance, the body does not produce β-galactosidase. As a result, lactose, unchanged entering the large intestine, is fermented by anaerobic microflora, which causes the formation of organic acids, gases and osmotic stress, which ultimately can significantly reduce the amount of galactose entering the body ... "
Fig.2. Gross KC et al. J Inherit Metab Dis. 1991;14(2):253-8.
The content of galactose in various dairy products varies in quantity from 7.12 to 12.22 mg/100 g. In fermented milk, the amount ranges from 51.86 to 84.91 mg / 100 g. The concentration of glucose fluctuates within the same values. The amount of galactose in fermented milk and yogurt is usually higher than in other dairy products (Filmjölk, Onaka and A-fil).
INFLUENCE OF STORAGE TEMPERATURE ON THE CONTENT OF GALACTOSE IN MILK.
The galactose content is lowest in milk stored at 20°C (7.02 mg/100 g) and highest in milk stored at 30°C (11.30 mg/100 g).
In milk stored at 4°C, the final galactose content is about 7.74 mg/100 g. The amount of galactose increases during the first week of storage, and then there is a persistent downward trend in concentration.
Note on the table above:
Butter oil- ghee.
Ghee- Ghee (a type of refined ghee that is widely used in South Asia).
Butter- butter.
GALACTOSEMIA
"... Galactosemia is a hereditary disorder of carbohydrate metabolism, in which an excess of galactose and its metabolites (galactose-1-phosphate and galactitol) accumulate in the body, which causes the clinical picture of the disease and the formation of delayed complications. The type of inheritance of galactosemia is autosomal recessive.
Galactosemia refers to hereditary diseases of carbohydrate metabolism and combines several genetically heterogeneous forms. The disease is based on a deficiency of one of the three enzymes involved in the metabolism of galactose: galactose-1-phosphate uridyltransferase (GALT), galactokinase (GALA) and uridine diphosphate (UDP)-galactose-4-epimirase (GALE). Three genes are known, mutations in which can lead to the development of galactosemia.
The pathogenetic mechanisms of galactosemia are still not fully understood. As a result of insufficiency of any of the three enzymes - GALT, GALA or GALE - the concentration of galactose in the blood increases. With a deficiency in the activity of GALT and GALE enzymes, in addition to an excess of galactose, an excess amount of galactose-1-phosphate also accumulates in the patient's body, which is currently considered the main pathogenetic factor causing most of the clinical manifestations of galactosemia and the formation of delayed complications. Excess galactose in the body can be metabolized by other biochemical pathways: in the presence of NADP·H (or NADH), it can be converted to galactitol. The accumulation of galactitol in the blood and tissues and an increase in its excretion in the urine is observed in all forms of galactosemia; in the lens of the eye, an excess of galactitol contributes to the formation of cataracts. There is evidence that a high content of galactitol in the brain tissues contributes to the swelling of nerve cells and the formation of a brain pseudotumor in some patients. Pathological processes in galactosemia are caused not only by the toxic effect of these products, but also by their inhibitory effect on the activity of other enzymes involved in carbohydrate metabolism (phosphoglucomutase, glucose-6-phosphate dehydrogenase), resulting in hypoglycemic syndrome ... "
EPIDEMIOLOGY
"... The average incidence of galactosemia is 1 case per 40,000 - 60,000 newborns, less often this disease occurs in some Asian countries. Based on the results of the newborn screening program, the incidence of classical galactosemia is 1:48,000. In Ireland, it is defined as 1 :16 476. If the results of determining the activity of the enzyme galactose-1-phosphate tauridyltransferase (GALT) of erythrocytes (less than 5% of the control activity) and the concentration of galactose-1-phosphate of erythrocytes (more than 2 mg / dl) are used as diagnostic criteria, then the estimate of the frequency of galactosemia increases and reaches 1:10,000. The frequency of the clinical variant of galactosemia is 1:20,000 and is estimated by the presence of the Ser135Leu/Ser135Leu genotype.
According to mass screening of newborns in Russia, the frequency of galactosemia is 1:16 242, in 2012 - 1: 20149. The results of neonatal screening for the period 2006-2008. made it possible to preliminarily estimate the frequency of galactosemia among newborns in the Krasnodar Territory: 1:19340, the classic version - 1:58021, the Duarte version 1:29010. The frequency of galactosemia in some regions and federal districts of the Russian Federation is presented in tables 1, 2 ... "
COMPLAINTS AND HISTORY
"... Against the background of breastfeeding, the newborn develops vomiting, diarrhea, muscular hypotension, drowsiness, lethargy. Weight gain stops, sluggish sucking is observed, mother's breast rejection, signs of liver damage appear and increase, often accompanied by hypoglycemia, jaundice and hepatosplenomegaly, bleeding from injection sites is often noted.The most severe manifestation of galactosemia in newborns is sepsis, which has a fatal course and is most often caused by gram-positive microorganisms, in 90% of cases - Escherichia coli.The disease usually manifests itself in the first days - weeks of life, rapidly progresses and in the absence of treatment is life-threatening.Insufficient weight gain, depression syndrome, less often CNS excitation, icterus (less often pallor) of the skin and mucous membranes, hepatosplenomegaly, an increase in the volume of the abdomen (ascites), dyspeptic disorders (vomiting, diarrhea), hemorrhagic syndrome, cataracts ..."
PERMISSIBLE DAILY QUANTITY OF GALACTOSE FOR PATIENTS WITH GALACTOSEMIA
Unlike patients with lactose intolerance, in patients with disorders of galactose metabolism, it is necessary to observe the individual reaction of the body to both lactose-containing and galactose-containing foods.
There is also a quantitative difference in the amount of lactose tolerated by patients with lactose intolerance and in patients with congenital disorders of galactose metabolism: a reduction in lactose intake may be sufficient for individuals with lactose intolerance, but the exclusion of only lactose-containing foods from the diet, in patients with congenital disorders of galactose metabolism may not be enough.
Dairy products in which the lactose content has been reduced by enzymatic hydrolysis contain equivalent amounts of galactose and glucose as found in the product prior to fermentation and are therefore not suitable for patients with galactosemia. The sources of galactose are mainly milk and its lactose-containing milk (cow's milk contains 4.5 to 5.5 g lactose/100 ml or 2.3 g galactose/100 ml). Many fruits and vegetables and dairy products contain some free galactose (yogurt 900 to 1600 mg, cheddar cheese 236 to 440 mg, blueberries 26 ± 8.0 mg, melon 27 ± 2.0 mg, pineapple 19 ± 3.0 mg / 100 g wet weight). The intake of galactose by healthy people in industrialized countries ranges between 3 and 14 g per day (Forges et al., 2006; Gropper et al., 2000). … It has been suggested that only foods with a galactose content of ≤5 mg/100 g should be introduced into the diet of patients with severe galactosemia, and for patients with less severe forms of galactosemia, the intake of galactose from food should be limited to 5 to 20 mg/100 g. (Gropper et al., 2000).
The estimate of acceptable daily galactose intake for patients with severe galactosemia is based on well-controlled observations in patients of the European Centers for the Treatment of Hereditary Metabolic Disorders (APS, 1997):
- for newborns from 50 to 200 mg / day,
- for preschool children from 150 to 200 mg / day,
- for children of school age from 200 to 300 mg / day,
- for adolescents from 250 to 400 mg / day,
- for adults from 300 to 500 mg / day
Based on these recommendations and assuming that the average recommended daily calorie intake for these age groups is in the range of 600, 1100, 1500, 2000 and 2500 kcal per day, respectively, then the optimal allowable amount of galactose for such people will be:
- for newborns (at 600 kcal / day) - about 8 mg (16 mg lactose) galactose / 100 kcal;
- for preschool children (at 1100 kcal / day) - about 14 mg (28 mg lactose) galactose / 100 kcal;
- for school-age children (at 1500 kcal / day) - about 13 mg (26 mg lactose) galactose / 100 kcal;
- for adolescents (at 2000 kcal / day) - about 13 mg (26 mg lactose) galactose / 100 kcal;
- for adults (at 2500 kcal / day) - about 12 mg (24 mg lactose) galactose / 100 kcal.
LINKS:
1. Clinical recommendations. Galactosemia in children. ICD 10: E74.2. Year of approval (revision frequency): 2016 (revision every 3 years). Russian Union of Pediatricians [pdf ]
2. Dietary carbohydrates: sugars and starches. US Department of Agriculture [pdf ]
3. A.A. Kostenevich, L.I. Sapunova. BACTERIAL β-GALACTOSIDASES: BIOCHEMICAL AND GENETIC DIVERSITY. Institute of Microbiology of the National Academy of Sciences of Belarus, Minsk, Republic of Belarus. Proceedings of BSU 2013, volume 8, part 1, 52 UDC 577.15+572.22 [pdf ]
4. Kolman Ya., Rem K.-G. VISUAL BIOCHEMISTRY: Per. with him. - M .: Mir, 2000 - 469 p.
5. Liu G et al. Galactose metabolism and ovarian toxicity. Reprod Toxicol. 2000 Sep-Oct;14(5):377-84.
6. Gross KC et al. J Inherit Metab Dis. 1991;14(2):253-8.
7. Kim HO et al. Free galactose content in selected fresh fruits and vegetables and soy beverages . J Agric Food Chem. 2007 Oct 3;55(20):8133-7. Epub 2007 Sep 11.
8 Agnes Abrahamson Galactose in dairy products. Faculty of Natural Resources and Agricultural Sciences Department of Food Science. Publication/Sveriges lantbruksuniversitet, Institutionen för livsmedelsvetenskap, no 401 Uppsala, 2015 [pdf ]
9 Portnoi PA et al. The lactose and galactose content of milk fats and suitability for galactosaemia. Mol Genet Metab Rep. 2015 Oct 22;5:42-43. doi: 10.1016/j.ymgmr.2015.10.001. eCollection 2015 Dec.
10. S.Ya. Volgina, A.Yu. Sanov. Galactosemia in children. PRACTICAL MEDICINE UDC 612.6.05
11. Scientific Opinion on lactose thresholds in lactose intolerance and galactosaemia. EFSA Journal 2010;8(9):1777. . doi:10.2903/j.efsa.2010.1777. European Food Safety Authority, 2010, EFSA Journal 2010;8(9):1777
12. Van Calcar SC et al. Galactose content of legumes, caseinates, and some hard cheeses: implications for diet treatment of classic galactosemia. J Agric Food Chem. 2014 Feb 12;62(6):1397-402. doi:10.1021/jf404995a. Epub 2014 Feb 3.
