Polyunsaturated fats for improved health and weight loss. Polyunsaturated fatty acids - PUFA

Diet modern man abounds in potential toxic substances- polyunsaturated fatty acids (PUFAs). Many people find it difficult to decide which fats are actually healthy and which are harmful. This article will answer these questions and show that limiting your PUFA intake is an important step towards achieving and maintaining good health.

The fats we eat in food are divided into three types: saturated (mostly animal fats), monounsaturated and polyunsaturated. Oils obtained from plant and animal sources often contain mixtures of all these types of fats. For example, olive oil, consisting mainly of monone saturated fat, also contains some polyunsaturated fats. Most vegetable oils, with the exception of coconut, olive and palm, are high in PUFAs, while most animal fats are high in saturated and monounsaturated fats.

The two main groups of dietary PUFAs are omega-3 and omega-6. Both groups are considered essential for the human body, since they are not synthesized in it and must be supplied with food. The impossibility of their synthesis by the body suggests that their irreplaceability may be exaggerated, because in the case of others it is true essential substances, such as glucose, monounsaturated and saturated fats, the body can synthesize them when necessary. In addition, deficiency of PUFAs in the body is an extremely rare phenomenon. The amount of PUFAs required for normal functioning organism, are extremely small and the need for them is easily satisfied from natural sources.

PUFAs occupy very a small part fat component of our body, while most of it is saturated and monounsaturated fats. It is reasonable to assume that admission nutrients into the body must occur exactly in the ratio that naturally is already present in it.

One of the main problems with PUFAs is their chemical instability. PUFA molecules contain more than one double bond, which makes them very vulnerable to the effects of environment. Outside our body, these fats easily go rancid and oxidize under the influence of heat, light and atmospheric oxygen. Inside it, PUFAs easily react with proteins and sugars, forming toxic byproducts called advanced glycation end-products, causing great harm body. In addition, PUFAs react more actively with fructose than with glucose, so PUFA intake should be minimized, especially when combined with fruit.

Since PUFAs are unstable fats, they excess consumption leads to the fact that being components cell membranes, they make cells fragile and susceptible to oxidation. Such PUFAs promote the oxidation of low-density lipoproteins (LDL, in common parlance “ bad cholesterol"), thereby creating a very unstable and atherogenic form of this cholesterol transporter in the blood.

Despite the indispensability of PUFAs, their excessive intake into the body also creates problems associated with modulating the activity of inflammatory eicosanoids. The process of inflammation itself is important for the body as a response to the invasion of infections, viruses or injuries, but the chronic course of this process becomes dangerous. Moderate inflammatory process stimulates immune system, and the chronic one depresses it. Therefore, small amounts of PUFAs are necessary to control inflammatory reactions in the body, but their excess leads to chronic inflammation and disease. It is not unreasonably believed that this chronic inflammation is the cause of almost all modern diseases (cardiovascular diseases, type 2 diabetes, obesity, metabolic syndrome, irritable bowel syndrome, rheumatoid arthritis, asthma, cancer, autoimmune diseases), and that excess consumption of PUFAs plays a significant role in this.

The correct ratio of PUFAs in the diet

Among adherents of the Paleolithic way of eating, there has long been debate about what the correct ratio of omega-6 and omega-3 PUFAs in the diet should be. The thing is that both groups use the same metabolic pathways in the body, competing with each other, and therefore an excess of PUFAs of one of them leads to suppression of the action of the other and vice versa. In addition, omega-3s are considered anti-inflammatory, as they mitigate the inflammatory effects of omega-6s. Considering that grain vegetable oils, the main part of which are omega-6 PUFAs, make up a significant proportion of the modern person’s diet, an excess of omega-6 and a deficiency of omega-3 is created in it. Correct ratio Omega-6 and omega-3 range from 1:1 to 4:1, while most people consume them in a ratio of about 20:1 or more! A general excess of PUFAs, and even with a predominance of omega-6, inevitably harms the body.

IN last years The popularity of dietary supplements with omega-3 PUFAs has increased, particularly in the form of fish oil capsules. Despite the fact that there can be both fatty fish (salmon, sardines, herring) and some seeds (flax), fish is still a more preferable source, since it contains them in a more bioavailable form for our body in the form of eicosapentaenoic acid (eicosapentaenoic acid). EPA) and docosahexaenoic acid (DHA). Omega-3 PUFAs in plant sources are found in the form of linolenic acid (LA), which in our body must go through a chain of complex transformations before reaching a state in which the body could use it. The efficiency of such processes is extremely low, and in the human body only 5% of LA is converted into EPA and DHA.

Excess Omega-3

As mentioned above, we need omega-3 PUFAs in small quantities and their excess can cause problems, since chemically they are very unstable, even more unstable than omega-6. Paying attention to the balance of omega-6 and omega-3, do not forget that the total amount of PUFAs consumed should also be limited. The best way to balance both groups of PUFAs in the right proportion is to keep your intake of omega-6 PUFAs to a minimum, while getting omega-3 PUFAs from natural animal sources.

Fish oil capsules as a source of omega-3 PUFAs are not always an ideal solution, since these capsules are often stored for a long time before being sold and can be exposed to sunlight, which turns the omega-3 PUFAs in them into poison for our body. Much best source You can call the consumption of omega-3 only in fresh fatty fish, which contains fat unchanged. But if for some reason regularly eating fresh oily fish is not possible for you, you can take fish fat in capsules, provided that they are produced renowned manufacturer with a good reputation in the market and until sale are stored in compliance with all conditions.

conclusions

Excess PUFAs in the diet (particularly PUFAs from omega-6 vegetable oils) have been associated with an increase in modern diseases, as these fats are susceptible to denaturation and oxidation in and outside the body. The total amount of PUFA consumed should be kept to a minimum, with the ratio of omega-6 to omega-3 as close to 1:1 as possible. Omega-3 PUFAs are best obtained from fresh, fatty fish. PUFAs should not be subjected to heat treatment. For the same reason, it is not recommended to fry in olive oil, despite the fact that the PUFA content in it is quite low (on average about 10% depending on the variety and manufacturer). The total content of PUFAs in the diet should not exceed 7-8% of the total calorie content (other sources recommend even smaller amounts - up to 1-2%). It is recommended to avoid all vegetable oils except coconut, olive and palm, and to thermally process food using oils low in PUFAs ( melted butter, coconut oil, lard), and also limit the consumption of nuts with high content Omega-6 PUFAs, especially fried ones. According to these recommendations, approximately 0.5 kg of fresh oily fish per week as a source of omega-3 will be enough to balance your omega-6 intake.

The article used materials

The human body is created from living tissues, which during the life process not only perform their functions, but also recover from damage, maintaining their performance and strength. Of course, for this they require nutrients.

Human nutritional balance

Food supplies the body with the energy it needs to support all body processes, especially muscle function, tissue growth and renewal. It should be remembered that the main thing in proper nutrition is balance. Balance is the optimal combination of foods from five groups necessary for human nutrition:

dairy products;
foods enriched with fats;
cereals and potatoes;
vegetables and fruits;
protein food.

Types of fatty acids

Unsaturated ones are also divided. The latter are polyunsaturated and monounsaturated. Saturated fatty acids are present in butter and hard margarines, polyunsaturated - in vegetable oil, fish products and some soft margarines. Monounsaturated acids are found in rapeseed, flaxseed and olive oil. The most necessary and healthy among them are the latter.

Health effects of unsaturated fatty acids

They have antioxidant properties and protect cholesterol contained in the blood from oxidation. Recommended poly intake unsaturated acids- about 7% of the daily portion and monounsaturated - 10-15%.

Unsaturated fatty acids are essential for the normal functioning of the entire body. Omega-3 and Omega-6 complexes are considered the most valuable of them. They are not synthesized independently in the human body, but are vital for it. Therefore, you should definitely include them in your diet, choosing the most optimal foods rich in these substances.

Properties of Omega acids

Nutritionists have long been interested in the functions of Omega-3 acids and their derivatives - prostaglandins. They tend to turn into messenger molecules that stimulate or suppress inflammation, and are very useful for swollen joints, muscle pain, bone pain, which is often observed in older people. Unsaturated fatty acids strengthen the immune system and mitigate the symptoms of rheumatoid arthritis and osteoarthritis.

They improve bone mineralization, while increasing their density and strength. In addition, Omega-3 unsaturated fatty acids are extremely beneficial for the heart and blood vessels. Complexes of Omega-unsaturated acids are also successfully used in for cosmetic purposes as food additives, they have a positive effect on skin health. Saturated and unsaturated fatty acids differ in their dietary properties: V unsaturated fats Fewer calories than the same amount of saturated fat. Omega-3 chemical molecules consist of a paired connection of 3 carbon atoms with a methyl carbon, and Omega-6s are linked by a paired connection of six carbon atoms with a methyl carbon. Omega-6 fatty acids are found most abundantly in vegetable oils and in all varieties of nuts.

Foods with high concentrations of unsaturated fatty acids

Sea fish such as tuna, salmon and mackerel are rich in Omega-unsaturated fatty acids. Their plant analogues include flaxseed and rapeseed oil, pumpkin seeds, and various types of nuts. Fish oil contains omega-3 fatty acids. It can be completely replaced by linseed oil.

The best source of these substances is fatty fish such as mackerel, but you can introduce unsaturated fatty acids into your diet in a variety of ways.

Buy omega-3 fortified foods. Nowadays they are often added to bread, milk and cereal bars.
enjoy linseed oil, replacing sunflower and butter. Add ground flax-seed in baking flour, salads, soups, cereals, yoghurts and mousses.
Include nuts in your diet, in particular walnuts, Brazil nuts, pine nuts and others.
Add unrefined olive oil to any food. It not only nourishes the body essential acids, but also helps to digest food.

Patients suffering from diabetes or taking anticoagulants should consume unsaturated fatty acids with caution. May affect blood clotting and sugar regulation. Pregnant women should not take fish oil, because it contains a lot of vitamin A, which is dangerous for the intrauterine development of the fetus.

Unsaturated fatty acids in foods

Monounsaturated acids are generous:

fish fat;
olives;
avocado;
vegetable oils.

Polyunsaturated fats:

nuts;
pumpkin, sunflower, flax, sesame seeds;
fatty fish;
corn, cottonseed, sunflower, soybean and linseed oils.

Saturated fats are not as bad as people think they are, and you shouldn't give them up completely. Monounsaturated and polyunsaturated fats should be the main ones in the daily portion of fat, and are needed by the body from time to time, as they promote the absorption of proteins, fiber, and improve the functioning of sex hormones. If fats are completely removed from the diet, memory functions are weakened.

Trans isomers in food consumed

In the process of preparing margarine, modification of unsaturated vegetable fats occurs under the influence of high temperatures, causing trans-isomerization of molecules. All organic matter have a specific geometric structure. When margarine hardens, cis isomers turn into trans isomers, which affect the metabolism of linolenic acid and provoke an increase in the level of bad cholesterol, causing heart and vascular diseases. Oncologists claim that trans isomers of unsaturated fatty acids provoke cancer.

Which foods contain the most trans isomers?

Of course, there are a lot of them in fast food, cooked in a lot of fat. For example, chips contain about 30%, and French fries contain more than 40%.

In confectionery products, trans isomers of unsaturated fatty acids range from 30 to 50%. In margarines their amount reaches 25-30%. In mixed fats, 33% of mutation molecules are formed during the frying process, since overheating causes transformation of molecules, which accelerates the formation of trans isomers. If margarine contains about 24% trans isomers, then during frying their level increases significantly. In crude oils plant origin There are up to 1% trans isomers; in butter there are about 4-8%. In animal fats, trans isomers range from 2% to 10%. Remember that trans fats are junk and should be avoided entirely.

The effect of polyunsaturated fatty acids on the human body has not yet been fully studied, but it is now obvious that for healthy active life, a person must introduce foods that contain unsaturated fatty acids into his diet.

Omega-3 fatty acids are essential substances for the normal functioning of human organ systems. They are almost never produced in the body and must be supplied with food. PUFAs are mainly found in vegetable oils and fish oils. These foods should be consumed even during weight loss and dieting, not to mention conditions such as pregnancy or intense physical exercise. Why are Omega acids needed? A deficiency of these compounds causes the development of many pathologies and diseases.

Omega fatty acids are essential for the normal functioning of the body

Omega-3 includes 11 fatty acids. They are called unsaturated because in the long chain of the molecule there are double bonds between some carbon atoms. The three most valuable fatty acids are Omega-3: alpha-linolenic, eicosapentaenoic and docosohexaenoic. What are these acids for? About this in the article.

Alpha-linolenic

What is alpha-linolenic acid (ALA)? It is a polyunsaturated fatty acid and is a precursor to other polyunsaturated fatty acids. When it enters the body, it quickly turns into eicosapentaenoic acid (EPA), which has more important for metabolism. In addition, it takes part in the formation of docosahexaenoic fatty acid (DHA) and prostaglandins. It should be taken into account that the conversion of ALA to docosohexaenoic or eicosapentaenoic acid occurs with great difficulty in some groups of people. Among them:

newborns;
children with diathesis;
adults with atopic dermatitis;
aged people;
diabetics;
alcohol abusers;
during the recovery period after a viral infection.

What are the benefits of Omega-3 fatty acid ALA? It performs the following functions in the body:

promotes proper development of the fetus;

Omega-3s play an important role in fetal brain development

regulates arterial pressure, used for cholesterol;
retains moisture in epidermal cells and hair;
responsible for the transmission of nerve impulses and brain activity;
helps fight stress and much more.

Alpha-linolenic acid is responsible for human organs such as the brain, epidermis, ovaries and prostate, kidneys and retina.

A deficiency of alpha-linolenic acid leads to weakness and loss of coordination. At the same time, the ability to learn decreases, blood pressure increases, visual disturbances and changes in mood occur. ALA deficiency results in dry skin and a tingling or numb feeling in the hands and feet. Due to its chronic deficiency, thrombosis and cardiac dysfunction can occur.

What foods contain Omega3 alpha-linolenic acid? There is a lot of it in plant seed oils: flax, pumpkin, rapeseed, Walnut. It is also present in the seeds themselves. In addition, ALA is found in beans, soybeans and leafy vegetables that are dark green in color. The recommended daily dosage is 2 g. This amount of acid is contained in 25 g of rapeseed oil.

Eicosapentaenoic acid

Eicosapentaenoic fatty acid (EPA) also belongs to the Omega-3 group. It is conditionally replaceable, as it is synthesized in small quantities from alpha-linolenic or docosohexaenoic acid. In the latter case, synthesis occurs in cases of extreme necessity, since this process requires a sufficient amount of energy.

EPA deficiency often occurs in newborns (especially premature babies) due to insufficient development of the enzymatic system and the inability to obtain EPA from alpha-linolenic acid. The same thing happens with skin diseases: the enzyme responsible for its synthesis works ineffectively or does not participate in the reaction at all.

Omega-3 PUFAs are essential fatty acids

Omega-3 polyunsaturated fatty acid eicosapentaenoic acid performs the following functions in the body:

necessary for lowering cholesterol;
normalizes the process of lipid transfer in the bloodstream;
promotes better absorption of fat-soluble vitamins in the gastrointestinal tract (gastrointestinal tract);
takes part in the synthesis of hormones;
part of the cell membrane;
suppresses autoimmune reactions;
activates the immune system;
regulates water balance;
supports joint mobility;
controls the level of fats in the blood and others.

This unsaturated Omega-3 fatty acid controls the brain, eggs and sperm, and the retina.

EPA deficiency manifests itself as symptoms:

increased fluid content in the body, swelling;
dry skin;
penchant for infectious diseases;
vision problems;
states of inflammation;
feeling of "goosebumps" all over the body;
slow growth in children;
high triglyceride levels;
hypertension;
difficulty losing weight;
deterioration of attention and memory.

Omega-3 deficiency negatively affects all higher mental functions

Marine fish contain large amounts of eicosapentaenoic fatty acid Omega-3: herring, halibut, salmon, mackerel, sardines. In addition, high EPA content is noted in cod liver. Most EPA is found in fresh fish; during the process of freezing and subsequent thawing, its amount decreases. Omega-3 PUFAs can be oxidized in the body, so it is recommended to take them simultaneously with vitamin E, which is a powerful antioxidant. The optimal daily human need for EPA is 2 g.

Docosohexaenoic

The third acid related to Omega-3 polyunsaturated fatty acids is docosohexaenoic acid (DHA). It is a component of lipids in most body tissues. It is a conditionally essential acid, just like EPA. It comes from food and is formed in small quantities in the body from alpha-linolenic acid. DHA itself is a precursor for EPA and prostaglandins. People who have diabetes cannot convert alpha-linolenic acid to docosahexaenoic acid, so they need to take an additional 0.3 g of DHA per day.

The main functions that docosohexaenoic acid performs in the body are:

prevents fat deposits;
helps prevent cancer;
suppresses inflammatory processes;
strengthens cell membranes;
normalizes brain processes;
maintains healthy rheological properties of blood;
eliminates depression;
increases immunity;

Omega-3s help strengthen the immune system

improves skin condition;
prevents allergies;
supports heart function;
normalizes lipid composition.

In the body, DHA is responsible for nervous system, brain, sperm composition and retina. That is why, with its deficiency, depression, premature aging and inflammatory joint diseases develop. In addition, a lack of docosohexaenoic acid leads to atherosclerosis, strokes and heart attacks. Miscarriage and toxicosis, as well as increased activity in children, combined with a low level of learning, are also associated with a lack of this compound.

The source of Omega-3 fatty acid - docosahexaenoic acid - is the same products as EPA. The optimal daily intake is considered to be 0.3 g.

How much Omega-3 is required per day?

The daily requirement for Omega-3 fatty acids varies depending on gender and age. So, men need about 2 grams of unsaturated fatty acids per day. With high cholesterol and to prevent various metabolic disorders, about 1-1.5 g is enough for women. To promote proper development, improve academic performance and prevent diseases in children, 1 g of Omega-3 taken per day will be enough.

People involved in sports, physically active or those engaged in heavy physical labor need to consume approximately 5-6 grams of polyunsaturated fatty acids per day.

During pregnancy, the need for these compounds also increases. For proper fetal development, a daily intake of 1.5 to 2.5 grams of Omega-3 is required.

Omega-3 needs vary individually

Harm and contraindications of Omega-3

Despite the enormous benefits of Omega-3 for human health, acids should only be taken in the appropriate dosage. In addition, experts recommend conducting Omega-3 treatment courses with mandatory breaks. Constantly consuming additional amounts of them can reduce blood viscosity, which will cause heavy bleeding(for example, during menstruation or cuts).

Omega-3 consumption may cause allergic reactions in people with hypersensitivity. Those who have liver problems should be careful when taking medications containing these compounds.

How to take Omega-3

For Omega-3s to be beneficial, it is important to take them correctly. Preparations available for sale in pharmacies or sports nutrition stores usually come with instructions for use. Manufacturers include different amounts of unsaturated fatty acids in capsules; therefore, depending on the product, the indicated optimal dosage will be different from others. However, there are general rules for taking Omega-3.

Omega-3 should be taken after meals, approximately 20-30 minutes later. It is necessary to drink the drug with a large volume of plain water. The frequency of taking fatty acids for treatment is 3 times a day, that is daily dose should be divided into three times. If Omega is used as a prophylactic, then one dose per day is enough; wherein daily dosage reduced by 2-3 times. The course can last up to 3 months.

Polyunsaturated fatty acids include unsaturated fatty acids with two, three or more double bonds. This is linoleic (C 17 H 31 COOH), having two double bonds between the 9-10th and 12--13th carbon atoms; linolenic (C 17 H 29 COOH), having three double bonds between the 9-10th, 12-13th and 15-16th carbon atoms; arachidonic (C 19 H 39 COOH) acids. These highly unsaturated polyunsaturated fatty acids, in their biological properties, can be classified as vital necessary substances, in connection with which some researchers consider them to be vitamins (vitamin F).

PUFAs are essential vital substances that are not synthesized in the animal body. Physiological significance and the biological role of PUFAs are very important and diverse.

The most important biological property PUFAs is their participation as structural elements in such biologically highly active complexes as phosphatides, lipoproteins, etc.

PUFA - necessary element in the formation of cell membranes, myelin sheaths, connective tissue, etc.

A connection has been established between PUFAs and cholesterol metabolism, expressed in the ability to increase the excretion of cholesterol from the body by converting it into labile, easily soluble compounds (Dale, Reiser, 1955).

In the absence of PUFAs, cholesterol esterifies with saturated fatty acids, which are deposited on the walls of blood vessels (Sinclair, 1958). In the case of atherification of cholesterol with unsaturated fatty acids, a high level of cholesterol absorption in the intestine is observed (Lang, 1959). According to Lewis and Folke (1958), PUFAs contribute to the rapid conversion of cholesterol into cholic acids and their removal from the body.

PUFAs have a normalizing effect on the walls of blood vessels, increase their elasticity and reduce permeability (Holman, 1957).

There is evidence (Sinclair, Robinson, Poole, 1956) that PUFA deficiency contributes to coronary thrombosis.

PUFAs partially protect against metabolic disorders caused by the intake of large quantities of thyroidine.

A connection has been established between PUFAs and the metabolism of B vitamins (pyridoxine and thiamine), as well as with the metabolism of choline, which, under conditions of PUFA deficiency, reduces or completely loses its lipotropic properties.

Insufficiency of PUFAs negatively affects the ability to activate enzymes, the activity of which is inhibited by foods high in protein (Levy, 1957). Data have been obtained on the stimulating role of PUFAs on defense mechanisms the body and, in particular, increasing the body’s resistance to infectious diseases and the effects of radiation (Sinclair, 1956).

With PUFA deficiency, the activity of cytochrome oxidase in the liver increases sharply.

PUFA deficiency is manifested by skin lesions.

In animals with PUFA deficiency, duodenal ulcers are more often detected.

PUFAs, as well as some protein amino acids, are essential components not synthesized in the body, the need for which can only be satisfied through food. However, the conversion of some fatty acids to others is possible. In particular, the undoubted transformation of linoleic acid into arachidonic acid in the body has been established.

The participation of pyridoxine in the conversion of linoleic acid to arachidonic acid has been established.

The biologically optimal formula for balancing fatty acids can be the ratio of 10% PUFAs, 30% saturated fatty acids and 60% monounsaturated (oleic) acid in fat.

For natural fats, lard, peanut and olive oils come close to this fatty acid structure. The types of margarine currently produced mostly correspond to the given formula for balancing fatty acids.

According to the US National Nutrition Research Council (1948), the minimum daily requirement for PUFAs is determined to be 1% of the daily calorie intake. According to B.I. Kadykov (1956), the daily norm of PUFAs for adults is 1% of the daily calorie intake and for children - 2%. Seimar, Shapiro, Friedman (1955), based on studies conducted on animals (rats), recommend the daily norm of PUFAs for humans - 7 g. Summarizing and generalizing the available materials on the rationing of PUFAs, we can come to the conclusion that the norm of PUFAs for adults is 5-8 g per day. As already noted, arachidonic acid is the most biologically active, and 5 g of arachidonic acid is sufficient to satisfy the need for PUFAs due to its intake from food.