Carbohydrate Deficiency: Signs And Causes

Carbohydrates are a class of organic substances that are integral components of cellular and extracellular structures that perform a wide range of functions in our body - from structural to energy.

However, in the realities of the modern world, this is also the most predominant component of food: as a rule, almost half of the entire plate is allocated to the share of sugars. It is not surprising that most of the diseases of civilization arise precisely as a result of their excessive and uncontrolled consumption. Diabetes mellitus, early aging, arterial hypertension, and even impaired ventilation of the lungs - the number of pathologies directly or indirectly associated with their impaired metabolism is huge, and the list is likely to grow longer and longer every year.

The fear of sugars has replaced the horror that was once caused by fat-containing foods in the older generation - now low-carb diets have naturally come into fashion. But is the total rejection of these organic compounds useful? Or is this another extreme and not the most prudent fashion trends? Let's figure it out.

The role of carbohydrates in the body

The first thing all carbohydrates are invariably associated with is energy. Indeed, this is the most favorite source, willingly sent by all cells to the ovens of small mitochondria - and I must say that even tumor cells are no exception in this regard. Everyone loves sugar, from pathogenic fungi to bacteria - most of them still know how to ferment and use various classes of carbohydrates as a source of carbon.

However, in fairness, it must be added: yes, glucose is the most commonly used raw material in energy factories: the mechanism for its conversion has been studied and worked out for centuries - however, this is not the only substrate that our cells are able to oxidize. Amino acids, fats, ketone bodies - all of these can also act as coal and firewood, ensuring the relentless functioning of our body. It is quite logical, given the huge range of functions exhibited by proteins - from plastic to protective - that using them as the main raw material is not only not profitable, but also extremely unreasonable: for example, one of the common causes of immune deficiency is uncompensated proteinuria (that is, loss of protein from urine), the consequence of which is a decrease in the production of antibodies.

Fats, on the other hand, can not oxidize all organs - they are usually used in conditions of reduced intake or intracellular synthesis (in the extensive liver manufactory) of carbohydrates.

So, glucose is a universal raw material for energy production. The sugars that come with food begin to break down already in the oral cavity, where salivary amylase and maltase function. Their role, albeit far from the most key, is sharply limited with poor chewing of food and swallowing whole pieces. In addition, the worse the food is crushed, the greater the burden will fall on the stomach, the powerful muscle layer of which provides grinding and the formation of chyme - a semi-liquid slurry.

The main metabolic processes take place in the small intestine - here, pancreatic enzymes activated by bile break down long, branched carbon chains into simple monomer bricks, the absorption of which occurs on the villi of the epithelial lining.

Thus, glucose and some other, less interesting for us in the context of energy production, sugars enter the systemic circulation - hyperglycemia is observed, in response to which the pancreas actively secretes a hormone of a protein nature - insulin. This is a kind of guardian of order or, even more correctly, balance: its task is to return the concentration of glucose in the serum to its original, optimal level for the functioning of the whole organism. This is achieved by increasing the density of specific monosaccharide carriers on cell surfaces: it itself, devoid of fat-soluble properties, cannot pass through a selectively permeable membrane.

In addition, insulin must “turn on” (through cascade reactions) the processes of glucose utilization: the whole point is its restlessness - it, like a cat, can easily go back into the systemic circulation. This is the main reason why it is not glucose itself that is stored in the pantries of our liver, but the polymer glycogen formed by a huge number of its molecules connected to each other by chemical bonds. In other words, it is simply not profitable for cells to connect other, energy-consuming processes for its binding (for example, phosphorylation).

Carbohydrates: simple and complex

There are no "good" and "bad" carbohydrates - equally, as well as cholesterol. Each of the representatives of this class has its own function, no less important than other micro- and macromolecules in the composition of cells and tissues: otherwise there would simply be no point in their intake with food sources or in endogenous synthesis.

All sugars can be divided into simple and complex. The first are working building blocks, the second are polysaccharides - long, heavy molecules, often with branched side chains, built from monomers, which, in most cases, are glucose (of one or another spatial configuration).

Complex carbohydrates are “slow”: in order to use them as energy raw materials, the body must first split their skeleton into the original structural bricks - otherwise, there can be no question of any absorption process. Simple or “fast” sugars, when they enter the intestines, are directly absorbed - there is simply nothing for enzymes to break in their carbon chains - and, therefore, cause a rapid response from the insulin secreted by beta cells.

The secretion of this protein hormone with the use of polysaccharides is smoother: there is no sharp increase (due to the much more measured development of hyperglycemia) and the same steep decline, followed by hypoglycemia and its unpleasant manifestations.

Carbohydrates are the main source of energy

So, as mentioned earlier, glucose is a universal fuel. That's just for some populations of cells and even entire tissues, it may still be almost the only one.

At first glance, where is the logic? Why does our organism, which is practical, smart and constantly thinking about the economic side of any issue, prefer, first of all, to send sugar to the furnaces for the production of energy? It would seem that those who do not have body fat - the size of the pantries, however, vary significantly, but, as a rule, the majority of the population does not have a deficit. 9 kilocalories compared to 4, which gives 1 gram of carbohydrates when burned, is it profitable? And how!

And if we move away from the anatomy of adipose tissue and delve into biochemistry, it becomes even more incomprehensible: only 38 ATP molecules are formed during the utilization of glucose - and then, provided that all the enzymes are at the ready, and oxygen is supplied - otherwise, the process will end at the stage the formation of lactic acid (which, in fact, is observed during the active work of the muscles). On the contrary, the "efficiency" of fat exceeds three to four hundred ATP molecules - it all depends on the fatty acids included in its composition, which differ from each other in the degree of saturation of bonds and the length of the carbon chain.

However, there are limitations - and they are quite impressive, since our power plants still prefer to utilize sugar in the first place. The first and perhaps one of the most key shortcomings in lipid recruitment mechanisms is the need for mitochondria. These little organelles, which millions of years ago were free-living bacteria and, by accident or design, entered into a very beneficial partnership (or, in the language of biology, symbiotic) relationships with the cells they invaded, are concentrated in the cytoplasm in the form of funny , somewhat reminiscent of the images of shoes, figures.

So, these are our power plants - or, more simply, pumps that tirelessly generate energy. Embedded in their inner membrane is a respiratory chain—nothing more than a collection of different complexes, through which, like grasshoppers, electrons jump over and electrons are pumped out to the outside, all to create an electrochemical gradient. Not as scary as it sounds the first time.

But nothing appears from nowhere and does not disappear into nowhere - otherwise, what would be the meaning of the main postulate of chemistry about the conservation of the mass of matter? Similarly, the movements of electrons and protons are preceded by the oxidation of organic substrates, and its most important stages (for example, the Krebs cycle) take place here, in the mitochondrial matrix. However, there will always be exceptions - one of these is glycolysis - the main mechanism for the utilization of perhaps the most common simple carbohydrate - glucose. It is carried out, contrary to general trends, in the cytoplasm.

This, it should be noted, is very helpful for cells whose arsenal is devoid of mitochondria - erythrocytes. Their entire internal space is filled with a complex hemoglobin molecule - red blood cells do not even have a nucleus, and small power plants even more so. Why are they, if the main, paramount task is to bind as much oxygen as possible and, having given it away, bring carbon dioxide from the tissues into the alveoli of the lungs? With such a noble and vital goal, not only will you get rid of ballast, but also of seemingly irreplaceable components and ultrastructures. So, erythrocytes are not able to utilize fatty acids: they do not have stoves in which they could safely burn out.

The second snag is nervous tissue. The brain is one of the five so-called barrier organs: it is limited from circulating blood by an impregnable barrier - the blood-brain barrier (BBB), due to the existence of which, in particular, during embryonic development, cells of the immune system cannot “get acquainted” with its protein and lipid structures, therefore, with various kinds of pathologies, accompanied by a “fall” of an unshakable border, they begin to perceive them as strangers who illegally invaded the sovereign territory of the body, and, therefore, are subject to expulsion or death. However, the lack of a clear programming that this is “one's own” is not the only difficulty arising from the existence of the BBB. Another and no less important is its absolute impenetrability for large,

What happens when there is a deficiency of glucose?

The conductor of all functions - the brain - not only does not like to starve, but simply does not know how: the whole range of functions shouldered by it is too important. Here, the regulation of the work of internal organs, and motor activity, and even the limbic system with its emotions are not up to the strike with the refusal of food.

With a severe restriction of carbohydrate intake, the nervous system begins to sound the alarm no worse than any police siren. Small glycogen reserves set aside for a “rainy day” run out quickly, and when the loud “save us, we die!” reach the periphery, the liver is included in the work to provide the body with food: the ketogenesis factory is launched.

Ketone bodies are not such a tasty food compared to sugary glucose - it is not surprising that our brains get used to them immediately. However, humility invariably comes after resentment - energy, in any case, must be received from somewhere.

Muscles also contribute to the maintenance of emergency coexistence: destroying their proteins, they become donors of amino acids, which are converted into keto acids or are directly involved in the actively unfolding process of gluconeogenesis - the formation of glucose from non-carbohydrate components.

In fact, this is the reason, for the most part, for such paradoxical, at first glance, analyzes of patients on a low-carbohydrate diet: sugar does not enter their body, but the concentration of glucose in the serum remains within the normal range or even significantly increased. It's just that our body is too smart: it can not only split something, but also reproduce.

Do not confuse carbohydrate restriction with hypoglycemia - to be honest, they rarely accompany or result from each other - usually the result of the first is an increase in serum glucose, not a decrease in it.

What is hypoglycemia

It develops for three main reasons:

1. Excessive production of insulin by beta cells of the pancreas - this hormone of a protein nature strives with all its might to reduce the level of glucose in the blood by entering it into the cells and including it in various ways of utilization.

2. Insufficient intake of glucose from food (for example, when skipping one of the meals) or a decrease in production at the factory due to its formation in the liver - that is, a decrease in the efficiency of the previously mentioned gluconeogenesis.

3. Unplanned physical activity.

Clinical manifestations are invariably born from pathogenesis - they are the result of reactions occurring in the body aimed at compensating and stopping an unexpected (in a healthy or relatively healthy person) drop in serum glucose levels.

So, when glucose reaches a conditional mark of 3.8 mmol/l, the secretion of contra-insular hormones is actively observed - the antagonism of which in relation to insulin is manifested in the activation of all mechanisms that contribute to an increase in the concentration of glucose in the blood. This is the active connection of reserve glycogen reserves concentrated in the pantry of the liver, and gluconeogenesis with parallel inhibition of the mechanisms for the utilization of this sugar (pentose phosphate pathway, glycolysis, glycogenogenesis).

At this stage, when anxiety has not yet crossed the invisible line of total panic, the symptoms that arise are the result of activation, as a rule, so far only of the autonomic (autonomous) nervous system. These are the harbingers of the coming storm. Typically, patients experience:

• shiver;

• cardiopalmus;

• mydriasis - dilated pupils;

• pallor of the skin;

• dizziness;

• increased sweating;

• irritability.

Signs of a carbohydrate deficiency

Perhaps the most obvious sign is mood variability, irritability and even aggression. It's all about the dopamine system - the one that is responsible for the reward. And sugar in this regard is in no way inferior to drugs: it also stimulates a sense of pleasure.

This is most likely due to the past of our ancestors - those who lived in caves and hunted mammoths. It was not easy to find honey and sweet fruits, especially considering that mankind learned to grow various crops after more than one century. In addition, if, say, bitter was associated with poison or poison (it is not for nothing that taste buds are located precisely at the root of the tongue, and when eating this kind of food, a gag reflex occurs reflexively), then sweet did not cause a feeling of anxiety and was invariably associated with safety, peace and comfort.

The dopamine system is responsible for the action: castles in the air in our thoughts take on very specific forms, and we, having set goals and set a certain direction, begin to move towards the fulfillment of desires. However, dopamine pushes a person not only to reach for the stars and the sky - it is also responsible for self-preservation, and, therefore, not only replenishment, but also the accumulation of energy substrates. Thus, a sweet cake begins to be regarded as a profitable investment in case of a rainy day, and not empty calories.

Another fairly common complaint faced by patients who sharply limit carbohydrates in their diet is constipation, which occurs due to insufficient intake of fiber. Dietary fiber stimulates the motility of the large intestine and facilitates the process of excretion of feces.

Sometimes a noticeable loss of muscle mass is also observed - the body, in conditions of a decrease or complete absence of carbohydrate intake, triggers catabolism, i.e. breakdown, proteins. The resulting amino acids are sent to the factory of gluconeogenesis - the synthesis of glucose from non-carbohydrate components, which occurs, for the most part, in liver cells.

Reduced thyroid function - up to hypothyroidism, which has various forms (depending on the level at which violations occur), but in general manifested:

• slow metabolism and weight gain;

• chilliness, feeling cold;

• traces on the skin from underwear, tights, jeans;

• apathy and loss of strength;

• impaired memory and concentration;

• disruptions of the menstrual cycle;

• fragility of nails;

• dry hair.

A little later, we will talk in more detail about the relationship between the thyroid gland and carbohydrate deficiency.

Exhaustion of the adrenal glands - in conditions of insufficient intake of glucose, there is an increased release of cortisol, which stimulates the processes of the previously mentioned gluconeogenesis. The specific features are:

• fatigue;

• hypoglycemia, accompanied by vegetative manifestations;

• depression and weakness.

Carbohydrates and the thyroid

The thyroid gland is the queen of metabolism and one of the main conductors that regulate the processes of growth and development. It performs its functions due to the formation of thyroxine (T4) and triiodothyronine (T3) - and the first, I must say, is much more active in relation to its cells and target tissues.

All its proteins - thyroglobulin (TG), thyroperoxidase enzyme, which ensures the oxidation of iodine and TG iodination, as well as the thyrotropin receptor, which is produced by the adenohypophysis to control the functioning of this gland, are N-glycosylated - in other words, contain sugar components in their structure .

This process is nothing more than a post-translational modification of protein molecules, when, having been removed from the conveyor belt, they are sent for packaging to a neighboring department. This multi-stage process takes place on the tables of the multifunctional department - in the Golgi complex - and significantly affects the function, structure, stability of protein molecules, and also ensures the perception of various signals by them.

Attached sugar residues also affect the synthesis of thyroid hormones, the recognition of thyrotropin by its corresponding membrane receptor, as well as the functioning of some transport systems that carry out the transfer of iodine derivatives. So, proper glycosylation is the key to the normal functioning of the thyroid gland.

However, the use of a ketogenic diet as an adjunct to the mainstream therapy for one of the most common types of cancer - thyroid carcinoma - has many prerequisites.

In particular, it is known that tumor cells, unlike normal ones, are not able to utilize ketone bodies, the concentration of which in the blood increases with a decrease in glucose values ​​involved in the transmission of various signals in cancer cells. On the other hand, a low-sugar diet can only exacerbate cachexia, the extreme malnutrition that often accompanies cancer.

Menstrual irregularities

Menstrual irregularities that occur with a sharp restriction in the intake of carbohydrates may be associated with a decrease in the activity of the thyroid gland. In addition, under conditions of constant stimulation of cortisol, the cause of which we have already explained, the so-called steal syndrome of pregnenolone, the mother of all hormones synthesized by the adrenal cortex, is observed. And instead of going along the path of the formation of sex hormones, it is “spent” on the production of glucocorticoids and maintaining a state of chronic stress.

In addition, in the conditions of a decrease in fat mass, the production of leptin, the satiety hormone involved in appetite control, also decreases. It, acting on specific receptors of the hypothalamus, one of the key structures of the brain, inhibits the production of neuropeptide Y, which stimulates the feeling of hunger.

However, the influence of leptin is not limited to eating behavior alone - it is directly involved in the work of the reproductive system and, moreover, is even synthesized by the placenta. This biologically active compound, first of all, ensures the regression of the corpus luteum - in case of non-pregnancy, and, according to recent studies, is also associated with the mechanisms of ovulation.

Functions of fiber

Fiber is usually partially fermented by resident bacteria, but is not broken down by digestive enzymes in the human body. Swelling and increasing, like cotton wool, in size, dietary fibers contribute to a more rapid onset of satiety - information from stretch receptors along the processes of neurons is transmitted to the corresponding centers of the brain.

In addition, some of their representatives are able to adsorb on their surface like cholesterol with bile acids (the latter, by the way, have a strong irritating and even toxic effect), slow down the absorption of carbohydrates, and even have antioxidant effects.

The minimum fiber content in the diet, according to average recommendations, should not be lower than 25-30 grams per day. Considering that it is not so easy to meet such rather high requirements (as we will demonstrate a little later, by giving some indicators of the concentration of dietary fiber in the most commonly consumed plant products), you can consider taking apple pectin or psyllium in the form of ready-made powders.

All dietary fibers, depending on their solubility in water, can be divided into soluble, capable of forming viscous gels, and insoluble, respectively. Separately, I would like to talk in more detail about such representatives of the first group as psyllium, obtained from the husk of psyllium seeds.

Studies note: its use was associated with a decrease in the level of glycated hemoglobin (HbA1c) - one of the most reliable indicators of carbohydrate metabolism, as well as insulin and C-peptide. This, according to scientists, was achieved by inhibition of glucose absorption (by about 12%) and its slow entry into the systemic circulation.