Glucose for brain function. Products useful for the brain and nervous system

mechanism for regulating blood sugar levels.
We often hear from our friends and acquaintances about blood sugar. Does every person have it? Oh sure. In fact, the blood contains glucose, which is formed in the intestines under the action of special substances (enzymes) from the sugars contained in food (for example, starch, which is found in cereals, potatoes, legumes). Therefore, in medicine, the term "blood glucose" is used. We will use this term in what follows.
Why does our body need glucose?
The fact is that it is the most important source of energy so that we can move, grow, think. Glucose can be compared to gasoline, which serves as a source of energy for the operation of a car.
Where does glucose come from in the body?
It comes to us with food when we have breakfast, lunch, dinner or a snack. After a person has eaten, the sugars contained in food are converted into glucose by the action of intestinal enzymes, which enters the blood from the stomach and intestines. Through the blood, glucose is carried to all cells of the body, in which it “burns out”, giving energy for the cells to work. Cells do a variety of jobs to keep the body alive. In order for the body to be constantly in the best physical form, glucose must be constantly available to the cells of the body. For this, the concentration of glucose in the blood must be within normal limits. If there is little glucose in the blood, there is not enough energy, and if there is a lot, then it turns into fat, and body weight grows.
Blood glucose can be checked in venous and capillary blood. The scores will vary slightly. So, when taking blood from a finger (capillary blood), the normal fasting blood glucose level is 3.3-5.5 mmol / l, and after eating it should not exceed 7.8 mmol / l. When taking blood from a vein (venous blood), the normal fasting glucose level is 3.9-6.1 mmol / l, and after eating no more than 7.8 mmol / l.

When we say on an empty stomach, we mean the morning hours after a 12-hour overnight fast, without brushing your teeth, not drinking any drinks (water, tea, coffee) and food, chewing gum, you should also give up cigarettes. A post-meal blood glucose test implies a 2-hour gap between a meal and a glucose test.
But the question arises - how does the body manage to maintain blood glucose levels so accurately? It turns out that in the pancreas, or rather in the islets of Langerhans, located mainly in its tail, special substances are produced - hormones that regulate blood glucose levels. The islets of Langerhans are composed of two types of cells: alpha cells (α cells) and beta cells (β cells). The hormone produced in α-cells is called glucagon, and the hormone produced in β-cells is called insulin. The hormones produced by the pancreas enter the bloodstream, from where they exert their regulatory effect on the entire body.
Insulin helps glucose enter the cells from the blood, and as a result, its level in the blood decreases. It can be thought of as a "key-keeper" that opens a "door" in the outer wall of the cell to allow only glucose to pass through it.
The production of insulin by the pancreas depends on the level of blood glucose - the higher it is, the more insulin is produced. This mechanism ensures the exact correspondence of insulin production to food intake - the more glucose from the gastrointestinal tract enters the blood, the higher its concentration in the blood and, accordingly, the higher the production of insulin. But insulin does not act on all tissues, but only on three, but the largest in the body - adipose, muscle and liver tissue. And this is not accidental, since its second task (but no less important) is the ability to store excess glucose from food. In the liver, insulin packs glucose into dense packets called glycogen. In adipose tissue, glucose is immediately converted to fat, and in muscle tissue it is converted to protein.
If there is not enough glucose, then under the action of glucagon it is first removed in its pure form from the liver, and if these reserves are not enough, then glucose is formed from fat cells, and finally, if there is not enough fat, protein reserves from the muscles are used.
The rest of the tissues take up glucose from the blood without the help of insulin, especially the brain, which is the main consumer of blood glucose and is most vulnerable to low or high blood glucose levels.

A chapter on the importance of glucose in our lives from the book Will and Self-Control.

“You, grandmother, first give a drink, feed a road person, and then ask,” Ivan Babe Yaga blamed Alexei Tolstoy in a fairy tale, and he was absolutely right. When we are hungry, the brain functions in emergency mode: it is severely undernourished and unable to perform complex tasks. The main fuel for the brain, unlike other organs, is exclusively glucose, which the body extracts from the food we eat.

Glucose - fuel for the brain

And modest appetites of the brain can not be called: although its mass is about 2% of body weight, the work of this organ takes about 20% of all calories received by the body. The brain does not have stores or spare warehouses, so it needs a constant supply of glucose: for smooth operation, our gray matter must absorb daily about 120 g of this sugar, which is equivalent to 420 kcal reduce the daily ration to about 0 kcal, and ideally even to negative values).

Glucose is a universal (although not the only) source of energy for the entire human body. As a result of a complex biochemical process called "glycolysis", glucose is broken down into simpler molecules, and the resulting energy is stored in the form of ATP - a special cellular "battery" that feeds all metabolic processes.

The brain produces ATP from glucose “on demand”: if, for example, the visual cortex needs energy at the moment, sugar begins to actively flow there, which is converted into energy on the spot. The main part (about 60-70%) of the kilocalories obtained from glucose is needed by the brain in order to conduct nerve impulses. In addition, he constantly spends energy on the synthesis of neurotransmitters - small, but extremely important molecules that control all aspects of the brain and through its mediation - the rest of the body, and their receptors.

For a long time it was believed that the concentration of glucose in different parts of the brain is approximately the same. However, in last years ultra-precise methods have been developed that allow you to determine the content of this sugar in certain regions of the brain. And it turned out that the observed homogeneity was just a consequence of imperfect measurements. In the same way, Mars seemed flat and smooth to astronomers for centuries, but powerful telescopes appeared - and observers were surprised to find out that its surface was completely covered with craters, mountain ranges, ruts and canyons.

To solve some problems, glucose is consumed literally in real time

Moreover, individual brain processes literally “suck out” glucose, and its content does not fall in the whole brain, but only in the areas that are responsible for solving a specific problem. For example, in rats that tried to learn how the passages in the maze were located, the sugar level in the hippocampus, the area of ​​the brain involved in processing and storing spatial information, dropped by 30%. It takes time to replenish the supply of glucose - and, in fact, glucose.

It is not yet possible to check what happens to sugar in the brain in humans: the new high-precision methods mentioned in the previous paragraph are good for everyone, but require that the subject be presented in the form of tissue sections.

But it is quite possible to see how a starving brain draws glucose from the blood. For example, if you make volunteers consistently subtract sevens from a hundred and take blood samples from them in parallel. The sevens test was invented in 1942 and has since been actively used (along with some other tasks) by doctors who suspect dementia and other brain disorders in patients.

Psychiatrists and neurologists believe that the test is not difficult, but it is easy to make mistakes in it if concentration is impaired. Measurements of the blood glucose concentration of volunteers before and after subtraction show that a huge amount of sugar is consumed by seemingly simple arithmetic efforts.

If you give participants sweet water before a math test, their blood glucose levels will still drop after the test, but they will do much better on the task..

Apparent simplicity

The amount of sugar in the brain determines whether we can resist temptations

The reader probably guessed that all this ranting about glucose is not without reason: yes, many researchers consider it to be the very resource that is depleted when we try to restrain our impulses. Of course, no one equates the supply of glucose in certain areas of the brain with the supply of willpower - this would be an incorrect simplification. But the very fact that in many ways it is this substance that determines whether we can resist temptations is finding more and more evidence.

At first glance, it seems rather strange to link such a complex process as self-control with such a banal thing as sugar. But if you dig a little deeper, this assumption does not look so crazy. Glucose, without any exaggeration, is one of the most important substances in our body, and violations of its metabolism lead to severe consequences for all organs, including the brain. Simplifying somewhat, we can compare glucose with gasoline: no matter how complex a car is, no matter how powerful its on-board computer is, if there is no fuel in the tank, none of these bells and whistles will help.

The reader may reasonably object that if there is gasoline, then the BMW of the latest model will overtake the old “nine” in all respects. This is certainly true, and we will discuss in detail the “built-in” mechanisms that determine willpower in the following chapters. But it's also true that if a BMW has problems with its fuel system to the controls, it won't ride much better than a 9.*

Normally, the body strives to maintain a constant concentration of glucose in the blood - approximately at the level of 4.2–4.6 mmol / l. Although, as mentioned above, the brain consumes glucose unevenly, “on average in a hospital” one can speak of a balance between the concentration of this sugar in general in the blood and in the brain. If the brain needs more glucose to perform a particularly difficult task, it draws it from the total supply of glucose in the blood - which means that the concentration of sugar there drops.

This was confirmed, for example, in the experiment described above with the successive subtraction of sevens. Accordingly, if you initially give the body additional glucose, for example, by pouring tea with sugar or another sweet drink into it, the brain will receive more resources to solve the problem: even if it is not possible to overcome it immediately, the available glucose will not run out. Conversely, if initially the blood sugar level is low, the brain will not have enough fuel for full-fledged work, and it will be less able to cope with its duties.

It is easy to devise experiments that will confirm or refute these assumptions. For example, give volunteers sugar water to drink, make them take the Stroop test, and then compare their results with the results of those who tried to ignore the meaning of colored letters without glucose “feeding”. Such experiments were carried out repeatedly, and subjects who had higher initial blood glucose levels actually completed the task faster.

In the good old days, when ethical committees weren't so rampant, researchers sometimes dabbled in radical experiments. In 1997, German neurophysiologists injected volunteers with a hefty dose of insulin in order to surely provoke a state of hypoglycemia in them - a significant decrease in blood sugar levels. Then the unfortunates were seated in front of a screen with two buttons and instructed to press them only when the necessary letters appeared on the monitor. desired color. Moreover, the right button was supposed to be pressed in response to one letter, say, “M”, and the left button - when another one was displayed, for example, “T”. This is not easy to do in normal condition, but without sugar, the percentage of errors and reaction time have become very indecently large .

A chocolate bar eaten in time will help maintain a figure

Laboratory experiments in which blood glucose levels have been tightly controlled (researchers of self-control have pricked hundreds of fingers) confirm that every exercise of willpower reduces the overall capacity for self-control - and glucose levels.

Hungry volunteers, who were first seated to look at the aunt silently opening her mouth and not be distracted by short words appearing next to her (try not to read store signs the next time you go out), and then, without feeding, were forced to perform the test Stroop, coped with it much worse than well-fed comrades. Auntie depleted the available resource of self-control, which was already small for the hungry subjects, so there was no strength left for the second task, which also required attention. For the lucky ones who got a muffin and sweet orange juice between the aunt and the Stroop dough, the colorful letters were much less of a problem.

If you force a well-fed person to solve any task that requires attention for a long time, sooner or later he will also begin to make mistakes, and the concentration of glucose both in the brain and in the blood will drop. But in the hungry, this effect is especially pronounced and comes faster. After you courageously forego the cake at lunch, it will be much more difficult to stay within the framework of a healthy diet at dinner. Therefore, those who lose weight abuse junk food precisely during the last meal, that is, just when it would be better to refrain from fatty and sweet foods. In addition to everything, closer to the night, the body, in principle, absorbs glucose worse, so it becomes almost impossible to fight the temptation.

For the same reason diets with super-strict restrictions most often lead to the opposite effect: having depleted the entire supply of willpower during the day, in the evening a person breaks down and sweeps away everything that is in the refrigerator.

In an effort to lose weight as quickly as possible, adherents of strict diets drastically limit the number of calories, and as a result, the brain of those who lose weight is constantly starving. And it is much more difficult for a hungry brain to resist temptations than a well-fed one.

In order to really lose weight, you need to limit yourself not too strictly. The idea that by cutting calories to the limit, you can achieve results as quickly as possible is good in theory. Unfortunately, our biochemistry disagrees.

How to understand how much glucose you need?

But there is no need to urgently eat a bar of chocolate before important negotiations or long painstaking work like writing an annual report: an increase in glucose levels above the level of perseverance required by the brain will not add , but extra pounds - completely.

The question arises: how to understand what it is, this necessary level? Theoretically, anyone can determine it for themselves by measuring blood glucose levels before, after, and during self-monitoring episodes. A few dozen measurements - and you will roughly understand what numbers we are talking about. There will be quite a trifle left: to determine what and how much you need to eat in order to maintain the desired value.

Well, do not forget to make adjustments from time to time for age, changes in metabolism (for example, if you have recovered or lost 20 kg, all measurements will have to be taken again), hormonal status, etc.

For those who for some reason do not want to do these simple manipulations, there is a simpler recipe. The experiments of a psychologist from the University of Minnesota, Kathleen Vos, showed that people with a depleted volitional resource react much more intensively to everything that happens around them: their emotional perception aggravates so much that even the pain from ice water seems much stronger than usual (pain is generally a very subjective thing, which is largely determined by our mood and emotions). A tired brain is unable to suppress its own reaction to stimuli, and the body reacts fully to even the most insignificant of them.

If you suddenly start crying after watching a sad movie, although you usually fall asleep at the cinema, or you are ready to kiss a bank employee because your turn has finally come, beware. Perhaps you have depleted your glucose supply and need to urgently replenish it so as not to do something stupid.

How to replenish, you guessed it: you need to eat. But be careful: due to the lack of glucose, there is almost no strength to control yourself, and it is very easy to eat a pack instead of a couple of cookies. Here, a nasty bug in our brain is fully manifested: the harder we try to overcome the temptation, the more the reserve of self-control is depleted, and the more it is depleted, the more difficult it is to resist the temptation. Such is the vicious circle. To break it, you must ... succumb to temptation! By allowing yourself a slight deviation from the rules, you will save yourself from a global breakdown.

Glucose, or as it is also called grape sugar, is the constituent unit of carbohydrates. It is found in many of the foods we eat. In addition, glucose is an integral part of the composition of the blood. That is why it must be supplied to the body in sufficient quantities. Today we will find out where glucose is contained, and find out the daily need for this substance.

General information about glucose

Useful properties of glucose

This product has the following properties that are beneficial to the body.

1. Provides the body with enough energy. It is glucose that increases efficiency and increases brain activity. Therefore, it is necessary for people doing hard physical work, as well as for those who, by the nature of their activity, have to “work with their brains”.
2. It has a positive effect on the nervous system. Glucose relieves stress and calms. That is why many people, when they are worried, really want to eat something sweet.
3. Improves the condition of the cardiovascular system. It contributes to the normal functioning of the heart, therefore, reduces the risk of developing a heart attack.
4. It removes harmful substances from the body, including toxins, so it is useful for various kinds of poisoning.
5. Helps to cope with colds.

Daily human need for glucose

Each person has their own daily requirement for glucose. In order to find out, you need to multiply 2.6 grams by body weight (for example, multiply 2.6 grams by 64 kilograms (your estimated weight), you get 166.4 grams). This will be the rate of use of this substance per day. However, there are situations when this figure can be slightly increased, but there are also cases when it needs to be reduced.

You can increase your glucose intake if you have to work hard both physically and mentally. In this case, you should listen to the signals of your body. If you become tired quickly and feel that you get hungry too quickly after eating, then you need to consume more glucose. However, you should not get too carried away with this, so that there are no health problems and excess weight.

The amount of glucose consumed should be reduced if you have a tendency to develop diabetes (hereditary predisposition or high blood sugar, which has not yet exceeded the permissible norm, but is already on the verge of it). Also, the rate of this product should be reduced if you lead a "sedentary lifestyle" and this is not related to your mental activity. Otherwise, you will have problems with being overweight. If you consume less glucose than expected, then the body will not have enough energy. Then he will take it from the fats entering the body, and will not put them in layers.

To properly compose a diet, you should know where glucose is contained. To do this, below we will give you a list of products in which it is present.

Signs of a lack of glucose in the body

The lack of glucose in the body is accompanied by the following symptoms.

1. Sluggish and indifferent to everything state.
2. Weakness of the muscles and interruptions in the work of the heart.
3. Fainting.

In this case, you need to seek help from a specialist, as well as include foods containing glucose in your diet.

Signs of an excess of glucose in the body

An excess of glucose in the body may not manifest itself outwardly, it can only worsen the general condition. In this case, only analyzes can show an excess of the norm. To find out, you need to donate blood for sugar content. The norm of glucose is 3.5 - 5.5. Exceeding it indicates a serious illness. In this case, it is tedious to visit an endocrinologist as soon as possible.

Foods and glucose

Products containing glucose

Glucose is present in the following foods. We will indicate its content in 100 gr.

1. Sugar - 99.9 gr.
2. Bee honey - 80.3 gr.
3. Marmalade - 79.4 gr.
4. Gingerbread - 77.7 gr.
5. Sweet straw - 69.3 gr.
6. Dates - 69.2 gr.
7. Pasta made from flour of the 1st grade - 68.4 gr.
8. Barley - 66.9 gr.
9. Raisins made from kishmish grapes - 65.8 gr.
10. Apple jam - 65 gr.
11. Rice - 62.3 gr.
12. Oatmeal - 61.8 gr.
13. Wheat flour - 61.8 gr.
14. Corn - 61.4 gr.
15. Buckwheat - 60.4 gr.

Foods that lower blood glucose

If you have a problem such as high blood glucose, but it is in no way associated with various diseases, then you can reduce it if you include foods in your diet that can do this. These are various nuts (for example, almonds, walnuts, peanuts, etc.), soy cheeses, some seafood (lobster, crabs), fresh vegetables (tomatoes, cucumbers, cabbage, zucchini, etc.), greens (lettuce , spinach), olives, black currants, citrus fruits, legumes, meat, fish, tea, etc. Including them in your diet will help lower your glucose levels to the right level. In this case, you do not have to give up products containing glucose.

Knowing where glucose is contained, as well as products that remove it from the blood, you can create the right menu that does not allow it to fluctuate. Therefore, you will always be "charged" with energy and your body will work without failure.

Many people sincerely believe that during intensive mental work it is necessary to eat, for example, a chocolate bar and thereby give the brain food for its vigorous activity.

That is why my posts about sugar addiction have so many comments: “But the brain needs glucose!” Yes, glucose, but not sugar.

So what does it really take for us to think fully?

Let's figure it out together.

How much glucose does the brain need?

The average person with average mental activity has a brain that needs about 100 grams of glucose, or about 300 kcal. The more intense the mental work, the more glucose your brain needs, up to 400 kcal.

But do not rush to rejoice, thinking that during the day you can safely drink sweet teas and soda, and this will only benefit. 100 g of non-sugar is glucose, sugar is only half of it, and the second part is fructose, which is incredibly harmful to our body, including the brain (which we will touch on in my new posts).

Where does the brain get glucose from?

Of course, the bloodstream delivers it to him. She gets there in different ways.

You eat carbohydrate food, it is digested and enters the bloodstream for a different time - fast carbohydrates give an instant jump in glucose and a quick drop (as they are quickly absorbed), and slow carbohydrates can give it away for several hours.

Glucose is also obtained from ... tatami! - protein food. Its synthesis from amino acids is called gluconeogenesis. If you are hungry and have only eaten chicken, it will completely feed the brain, or you (in extreme cases) will “eat” your own muscles.

We also have glycogen stores in the liver, about 100 grams. It is also in the muscles, but it is stored there just for them, but the liver keeps it mainly for the brain. If food is not supplied, and glucose is needed, the body processes glycogen, creating it from there.

What will happen to the brain if you do not eat fast carbohydrates?

Yes, nothing bad will happen if you are an ordinary, relatively healthy person. Our blood sugar levels don't fluctuate that much (unless you're: not diabetic, don't load bags of cement on an empty stomach, or have a diseased liver and aren't starving).

There will be no sweet rolls - glucose will be taken from see above: carbohydrates, proteins and glycogen stores in the liver. Therefore, you should not justify sugar addiction by saying that “the brain wants sweets” - it doesn’t. And who wants?

And what happens if you snack on sweets, trying to “feed” the brain?

The same sugar addiction, which is akin to drug addiction, will be formed. I ate sweets, and the production of serotonin and dopamine began, you get high.

But this quickly passes with a drop in blood glucose and these hormones of pleasure, again hunger and an acute desire for sweets - to get your portion of pleasure. Along with this, the withdrawal syndrome begins - irritation, anger.

So sugar for the brain is a myth?

Of course, look at large animals - buffaloes, tigers, even whales.))) They do not go crazy, their brain functions normally within its capabilities. Or on others whose diet consists of sweet fruits - they do not become smarter from this.

Great scientists, absorbed in science, doing research, making discoveries, may forget about food altogether - their brain does not signal, shouting to them: “Hey, eat sugar urgently!”.

So what's the truth?

You work intensively with your brain, you have stress that encourages you to crave sweets: it’s not the brain that wants it in order to add 2 + 2 better, but you want the production of the hormone of pleasure to improve your stressed state.

And the brain is already fine, and you have a sugar addiction. Don't be fooled anymore!

Glucose is a six-carbon sugar that helps the body release energy. It is found in vegetables, fruits, cellulose, starch and animal glycogen. The body's need for glucose depends on the type of human activity, his psycho-emotional state and physical activity. The more energy a person needs to perform a particular job, the higher his need for glucose.

The body's need for glucose

In order for the body to function normally, it needs a timely supply of glucose. However, in the case of a tendency to diabetes and a sedentary lifestyle, the need for glucose decreases. The body will get energy from the fat reserves of the body. Glucose is broken down very quickly in the body into water, carbon dioxide and energy.

The role of glucose for the body is high. It not only supplies energy to our body, but also has a detoxifying function. As a result, glucose is used both in the treatment of colds and in severe poisoning with toxins. Once in the body, glucose reacts with vitamins A and C, as well as water. Together with oxygen, it nourishes the red blood cells.

Deficiency of glucose in the body

A lot of people love sweets, and so many have given up on it. Indeed, for most people, sweets are associated with being overweight. However, a strict rejection of sweets is relevant only for people with diabetes. In other cases, it is worth understanding that the body needs energy that glucose can provide. With a lack of glucose in the body, a person can become lethargic and lethargic, muscle weakness occurs. Metabolism is disturbed and a malfunction of the cardiac system may occur.

People suffering from glucose deficiency are prone to disruption of the work of almost all organs and systems of the body. Headaches, loss of consciousness, problems with the nervous system and weakness are the main signs of glucose deficiency in the body. Fasting or very strict diets can lead to this. In order for diabetics to replenish their glucose reserves, it is worth giving preference to cereals, lamb and potatoes.

If the blood sugar level is higher than 5.5, be sure to visit a specialist. summon high level glucose could be sweets that were consumed the day before, or some diseases. In order to eliminate the risk of developing diabetes, be sure to visit an endocrinologist and review your diet. Remember that an excess of sweets adversely affects health.
If a lack of glucose is a general weakness and disruption of the nervous system, then an excess is obesity, diabetes mellitus and other endocrine diseases. Dried fruits, honey and sugar are glucose, which is absorbed as quickly as possible. Cereals contain glucose, which takes a long time to digest.
Table of glucose content in products

In most cases, foods high in glucose are the sweets that we love so much. However, you can get glucose with the help of cereals and dried fruits. At the same time, be sure to control the amount of sweets consumed to eliminate the risk of developing diabetes and obesity.