Useful fatty acids. Functions of fatty acids. Interaction with other elements

Fatty foods have long been considered harmful, both for the body as a whole and for the figure. However, not all fats have a negative effect on our body. Fatty acids are divided into and unsaturated. The former have a simple structure and solid form. Once in the blood, they form special compounds that settle in the form of a fatty layer. Excessive consumption of foods high in animal fats leads to obesity and cardiovascular pathologies.

Not all fats are harmful and dangerous to the human body. Unsaturated (vegetable) fatty acids are the “right” fats. They have a positive effect on well-being, and, despite the complex molecular formula, they do not clog blood vessels, but move freely through the arteries, increasing their elasticity, removing cholesterol. A lot of healthy fats in seeds, nut kernels, seafood, vegetables.

Monounsaturated fatty acids and their importance

This type of substances is divided into monounsaturated and polyunsaturated. Each type has its own advantages and features. Both options remain in a liquid state at any temperature. When deciding to include monounsaturated fats in a diet for men or women, you should understand what foods contain these substances. This type of useful elements enters the body along with the active components of rapeseed and sunflower oil, they are also found in peanuts and olives.

A group of scientists have conducted repeated studies, thanks to which they were able to prove that foods containing unsaturated fatty acids, in the right proportions, are effective for losing weight and gaining muscle mass during training. In addition, MUFA:

• helps fight low hemoglobin and breast cancer;
• improves the condition of patients with joint diseases such as rheumatism and arthritis;
• promotes the cleansing of blood vessels and arteries.

For a person leading an active lifestyle, the daily intake of unsaturated fatty acids is 20% of the total energy value of the menu. When purchasing products in supermarkets, be sure to carefully study the packaging. The labels always indicate the content of fats, proteins and carbohydrates.

This type of useful substances is not synthesized by our bodies. They get to a person from the food that we consume. Foods rich in fats are necessary to improve the functioning of the brain, nervous system, the functioning of the heart muscle and blood vessels.

Polyunsaturated fatty acids and their uses

Polyunsaturated fatty acids are divided into two types - omega-3 and omega-6. It is important to understand what these substances are and what they contain, because you can only replenish their reserves in the body with the help of food.

Omega-3 prevents pathologies of the heart muscle and stroke, lowers blood pressure, improves heartbeat and normalizes blood composition. Also, scientists came to the conclusion that the use of this substance helps to prevent the development of acquired dementia. PUFAs are indispensable during pregnancy and lactation, because everything that enters the mother's body receives the developing fetus.

You can saturate the body with omega-3 by supplementing the menu with certain products. What is a food rich in PUFAs? Pay attention to this list:

• fatty fish;
• flax seeds;
• soy and legumes;
• walnut kernels;
• shrimps.

Omega-6 is found in small amounts in avocados, eggs, whole grain bread, hemp and corn oil. This substance is necessary for the normal functioning of the digestive tract, improving the function of hematopoiesis, it is also involved in the formation of cell membranes, the development of vision and nerve endings.

If you introduce foods low in solid (saturated) fats into the diet, and at the same time increase the consumption of vegetable analogues, this will improve the overall tone of the skin and muscles, allow you to lose weight and improve metabolic processes.

The need for PUFAs increases with intense physical exertion, during a period of active growth, pregnancy, in the event of diabetes, heart disease. To reduce the consumption of fats should be with allergic manifestations, pain in the stomach, lack of physical activity, people in old age.

What to include on the menu

Unsaturated fats belong to the group of easily digestible substances. But you can not abuse food rich in these substances unique in their composition.

To speed up the absorption process, eat foods that have not been heat-treated. The melting point affects the breakdown of these substances and the rate of absorption into the blood. The higher it is, the worse the element is absorbed.

Unsaturated fatty acids are involved in the formation of the human immune system, brain and heart function. They improve memory, attention and help in the fight against depression. Without fat, the body does not absorb vitamins A, D, K, E. Eat healthy fats daily, the list of products presented in the table below will allow you to develop a complete and balanced menu for every day.

Unsaturated fatty acids are acids containing double bonds in the carbon skeleton.

Depending on the degree of unsaturation (the number of double bonds), they are divided into:

1. Monounsaturated (monoethenoid, monoenoic) acids - contain one double bond.

2. Polyunsaturated (polyethenoid, polyenoic) acids - contain more than two double bonds. Some authors refer to polyenoic acids as unsaturated fatty acids containing three or more multiple (double) bonds.

Unsaturated fatty acids exhibit geometric isomerism due to the difference in the orientation of atoms or groups relative to the double bond. If the acyl chains are located on one side of the double bond, cis- a configuration characteristic of, for example, oleic acid; if they are located on opposite sides of the double bond, then the molecule is in trance- configuration.

Table 6.3

unsaturated fatty acids

Continuation of the table. 6.3

The unsaturated fatty acids are hydroxy acids, for example, ricinoleic acid, which has a hydroxyl group at the C 12 atom:

C 21 H 41 COOH

CH 3 - (CH 2) 7 - CH \u003d CH - (CH 2) 11 COOH

Cyclic unsaturated fatty acids

Molecules of cyclic unsaturated acids contain little reactive carbon cycles. Typical examples are hydnocarpic and chaulmugric acids.

Hydnocarpic acid CH=CH

> CH–(CH 2) 10 –COOH

CH 2 -CH 2

Chaulmic acid CH=CH

> CH - (CH 2) 12 - COOH

CH 2 -CH 2

These acids are found in tropical plant oils used to treat leprosy and tuberculosis.

Essential ( essential)fatty acid

In 1928, Evans and Burr found that rats fed a low-fat diet, but containing vitamins A and D, experienced growth retardation and decreased fertility, scaly dermatitis, tail necrosis, and urinary system damage. In their work, they showed that this syndrome can be treated by adding essential fatty acids to food.

Essential (essential) fatty acids are acids that are not synthesized by the human body, but enter it with food. Essential acids are:

Linoleic C 17 H 31 COOH (two double bonds), C 2 18;

Linolenic C 17 H 29 COOH (three double bonds), C 3 18;

Arachidonic C 19 H 31 COOH (four double bonds), C 4 20.

Linoleic and linolenic acids are not synthesized in the human body, arachidonic acid is synthesized from linoleic acid with the help of vitamin B6.

These acids are vitamin F (from the English. fat- fat), are part of vegetable oils.

In people whose diet lacks essential fatty acids, scaly dermatitis, a violation of lipid transport, develops. To avoid these violations, so that the share of essential fatty acids accounts for up to 2% of the total calorie content. Essential fatty acids are used by the body as precursors for the biosynthesis of prostaglandins and leukotrienes, participate in the construction of cell membranes, regulate cell metabolism, blood pressure, platelet aggregation, remove excess cholesterol from the body, thus reducing the likelihood of developing atherosclerosis, increase the elasticity of blood vessel walls . Arachidonic acid has the highest activity, linoleic acid has the intermediate activity, the activity of linolenic acid is 8–10 times lower than linoleic acid.

Linoleic and arachidonic acids are w-6 acids,
a-linolenic - w-3-acid, g-linolenic - w-6-acid. Linoleic, arachidonic and g-linolenic acids are members of the omega-6 family.

Linoleic acid is included in the g-linolenic composition of many vegetable oils, found in wheat, peanuts, cotton seeds, soybeans. Arachidonic acid is found together with linoleic acid, especially in peanut butter, and is an important element of animal phospholipids. a-Linolenic acid is also found together with linoleic acid, especially in linseed oil,
g-linolenic - characteristic of rose oil.

The daily requirement for linoleic acid is 6-10 g, its total content in dietary fats should be at least 4% of the total calorie content. For a healthy body, the ratio of fatty acids should be balanced: 10-20% polyunsaturated, 50-60% monounsaturated and 30% saturated. For the elderly and patients with cardiovascular diseases, the content of linoleic acid should be 40% of the total fatty acid content. The ratio of polyunsaturated and saturated acids is 2:1, the ratio of linoleic and linolenic acids is 10:1.

To assess the ability of fatty acids to provide the synthesis of structural components of cell membranes, the coefficient of efficiency of essential fatty acid metabolism (EFA) is used, which shows the ratio of the amount of arachidonic acid (the main representative of unsaturated fatty acids in membrane lipids) to the sum of polyunsaturated fatty acids with 20 and 22 carbon atoms:

Simple lipids(multicomponent)

Simple lipids are esters of alcohols and higher fatty acids. These include triacylglycerides (fats), waxes, sterols, and sterides.

Waxes

Waxes are esters of higher monobasic fatty acids () and primary monohydric high molecular weight alcohols (). Chemically inactive, resistant to bacteria. Enzymes do not break them down.

General wax formula:

R 1 -O - CO - R 2,

where R 1 O - is the residue of a high molecular weight monohydric primary alcohol; R 2 CO is a fatty acid residue, mainly with an even number of C atoms.

Waxes are widely distributed in nature. Waxes form a protective coating on leaves, stems, fruits, protecting them from wetting with water, drying out, and the action of microorganisms. Waxes form a protective lubricant on the skin, wool, feathers, and are contained in the external skeleton of insects. They are an important component of the wax coating of the grape berry - pruin. In the shells of soybean seeds, the wax content is 0.01% by weight of the shell, in the shells of sunflower seeds - 0.2%, in the shell of rice - 0.05%.

A typical example of wax is beeswax containing alcohols with 24–30 C atoms (myricyl alcohol C 30 H 61 OH), acids CH 3 (CH 2) n COOH, where n= 22–32, and palmitic acid (C 30 H 61 - O–CO–C 15 H 31).

Spermaceti

An example of animal wax is spermaceti wax. Raw (technical) spermaceti is obtained from the head spermaceti cushion of sperm whales (or other toothed whales). Raw spermaceti is composed of white, scaly crystals of spermaceti and spermaceti oil (spermol).

Pure spermaceti is an ester of cetyl alcohol (C 16 H 33 OH) and palmitic acid (C 15 H 31 CO 2 H). The formula of pure spermaceti C 15 H 31 CO 2 C 16 H 33.

Spermaceti is used in medicine as a component of ointments with a healing effect.

Spermol is a liquid wax, a light yellow oily liquid, a mixture of liquid esters containing oleic acid C 17 H 33 COOH and oleic alcohol C 18 H 35. Spermol formula C 17 H 33 CO–O–C 18 H 35 . The melting point of liquid spermaceti is 42…47 0 С, spermaceti oil – 5…6 0 С. Spermaceti oil contains more unsaturated fatty acids (iodine value 50–92) than spermaceti (iodine value 3–10).

Sterols and sterides

Sterols(sterols) are high molecular weight polycyclic alcohols, the unsaponifiable fraction of lipids. Representatives are: cholesterol or cholesterol, oxycholesterol or oxycholesterol, dehydrocholesterol or dehydrocholesterol, 7-dehydrocholesterol or 7-dehydrocholesterol, ergosterol or ergosterol.

At the base of the building sterols lies a ring of containing fully hydrogenated phenanthrene (three cyclohexane rings) and cyclopentane.

Sterids- esters of sterols - are the saponifiable fraction.

Steroids- These are biologically active substances, the basis of the structure of which are sterols.

In the 17th century, cholesterol was first isolated from gallstones (from the Greek. hole- bile).

CH 3 CH - CH 2 - CH 2 - CH 2 - CH

It is found in the nervous tissue, brain, liver, is a precursor of biologically active compounds of steroids (for example: bile acids, steroid hormones, vitamins of group D) and a bioinsulator that protects the structures of nerve cells from the electrical charge of nerve impulses. Cholesterol in the body is in free (90%) form and in the form of esters. It has endo- and exogenous nature. Endogenous cholesterol is synthesized in the human body (70-80% of cholesterol is synthesized in the liver and other tissues). Exogenous cholesterol is cholesterol that comes from food.

Excess cholesterol causes atherosclerotic plaques to form on the walls of arteries (atherosclerosis). Normal level
200 mg of cholesterol per 100 ml of blood. With an increase in the level of cholesterol in the blood, there is a risk of atherosclerosis.

The daily intake of cholesterol from food should not exceed 0.5 g.

More cholesterol is found in eggs, butter, offal. In fish, a high cholesterol content was found in caviar (290–2200 mg/100 g) and milk (250–320 mg/100 g).

Fats(TAG, triacylglycerides)

Fats are esters of glycerol and higher fatty acids and are the saponifiable fraction.

General TAG formula:

CH 2 - O - CO - R 1

CH - O - CO - R 2

CH 2 - O - CO - R 3,

where R 1, R 2, R 3 are the residues of saturated and unsaturated fatty acids.

Depending on the composition of fatty acids, TAGs can be simple (they have the same fatty acid residues) and mixed (they have different fatty acid residues). Natural fats and oils contain mostly mixed TAGs.

Fats are divided into solid and liquid. Solid fats contain saturated carboxylic acids, these include animal fats. Liquid fats contain unsaturated acids, these include vegetable oils, fish oil.

Fish oils are characterized by polyene fatty acids having a linear chain and containing 4–6 double bonds.

The high biological value of fish oil is determined by the fact that fish oil contains:

Biologically active polyene fatty acids (docosahexaenoic, eicosapentaenoic). Polyenoic acids reduce the risk of thrombosis, atherosclerosis;

Vitamin A;

Vitamin D;

Vitamin E;

The trace element selenium.

Fish fats are divided into low-vitamin and high-vitamin. In low-vitamin fish oils, the content of vitamin A is less than 2000 IU per 1 g, in high-vitamin fish oils it exceeds 2000 IU per 1 g. In addition, vitamin A concentrates are produced industrially - fats in which the content of vitamin A > 10 4 IU
in 1 year

Fat quality indicators

The following physicochemical constants are used to assess the quality of fats.

1. Acid number.

A characteristic property of fats is their ability to hydrolyze. The hydrolysis products are free fatty acids, glycerol, monoacylglycerides and diacylglycerides.

Enzymatic hydrolysis of fats proceeds with the participation of lipase. This is a reversible process. To assess the degree of hydrolysis and the amount of free fatty acids, the acid number is determined.

The acid number is the number of milligrams of KOH used to neutralize all the free fatty acids that are contained in 1 g of fat. The higher the acid number, the higher the content of free fatty acids, the more intense the hydrolysis process. The acid number increases during the storage of fat, i.e. it is an indicator of hydrolytic spoilage.

The acid number of medical fat should be no more than 2.2, fortified fat intended for veterinary purposes - no more than 3, edible fat - 2.5.

2. Peroxide number

The peroxide value characterizes the process of oxidative deterioration of fats, as a result of which peroxides are formed.

The peroxide number is determined by the number of grams of iodine isolated from potassium iodide in the presence of glacial acetic acid, separating I 2 from it; the formation of free iodine is fixed using a starch paste:

ROOH + 2KI + H 2 O = 2KOH + I 2 + ROH.

To increase the sensitivity of the study, the determination of the peroxide number is carried out in an acidic environment, acting on peroxides not with potassium iodide, but with hydroiodic acid, which is formed from potassium iodide when exposed to acid:

KI + CH 3 COOH = HI + CH 3 COOK

ROOH + 2HI \u003d I 2 + H 2 O + ROH

The released iodine is immediately titrated with a solution of sodium thiosulfate.

3. Hydrogen number

The hydrogen number, like the iodine number, is an indicator of the degree of unsaturation of fatty acids.

Hydrogen number - the number of milligrams of hydrogen required to saturate 100 g of the studied fat.

4. Saponification number

The saponification number is the number of milligrams of KOH required to neutralize all the free and bound acids contained in 1 g of fat:

CH 2 OCOR 1 CH 2 - OH

CHOCOR 2 + 3KOH CH - OH + R 1 COOK +

CH 2 OCOR 3 CH 2 - OH

related fatty acids

R 2 COOK + R 3 COOK

RCOOH + KOH –––® RCOOK + H 2 O

free

fatty acid

The saponification number characterizes the nature of the fat: the lower the molar mass of TAG, the greater the saponification number. The saponification number characterizes the average molecular weight of glycerides and depends on the molecular weight of fatty acids.

The saponification number and acid number characterize the degree of hydrolytic spoilage of fat. The value of the saponification number is affected by the content of unsaponifiable lipids.

5. Aldehyde number

The aldehyde number characterizes the oxidative deterioration of fats, the content of aldehydes in fat. The aldehyde number is determined by a photocolorimetric method based on the interaction of carbonyl compounds with benzidine; determination of optical density is carried out at a wavelength of 360 nm. Cinnamaldehyde (b-phenylacrolein C 6 H 5 CH=CHCHO) is used to construct a calibration curve. The aldehyde number is expressed as milligrams of cinnamic aldehyde per 100 g of fat. The aldehyde number is an indicator of the quality of dried fish, as well as the second stage of oxidative deterioration of fats.

6. Essential number

The ester number is the number of milligrams of KOH required to neutralize the ester bonds of fatty acids (bound fatty acids) released during saponification in 1 g of fat. The ester number is determined by the difference between the saponification number and the acid number. The essential number characterizes the nature of fat.

Everyone talks about high and low fat foods, "bad" fats and "good" fats. This can be confusing for anyone. While most people have heard of saturated and unsaturated fats and know that some are healthy and others are not, few understand what this really means.

Unsaturated fatty acids are often described as "good" fats. They help reduce the chances of heart disease, lower blood cholesterol, and have a host of other health benefits. When a person partially replaces them with saturated fatty acids in the diet, this has a positive effect on the state of the whole organism.

Monounsaturated and polyunsaturated fats

"Good" or unsaturated fats are usually found in vegetables, nuts, fish, and seeds. Unlike saturated fatty acids, they remain liquid at room temperature. They are divided into and polyunsaturated. Although their structure is more complex than that of saturated fatty acids, they are much easier for the human body to absorb.

Monounsaturated fats and their impact on health

This type of fat is found in a variety of foods and oils: olive, peanut, canola, safflower, and sunflower. According to the results of numerous studies, a diet rich in monounsaturated fatty acids reduces the likelihood of developing diseases of the cardiovascular system. In addition, it can help normalize blood insulin levels and improve the health of patients with type 2 diabetes. Also, monounsaturated fats reduce the amount of harmful low-density lipoprotein (LDL) without affecting the protective high-density lipoprotein (HDL).

However, this is not all the health benefits of this type of unsaturated fat. And this is proved by a number of studies conducted by scientists around the world. So, unsaturated fatty acids contribute to:

1. Reducing the risk of developing breast cancer. Swiss scientists have proven that in women whose diet includes more monounsaturated fats (as opposed to polyunsaturated), the risk of developing breast cancer is significantly reduced.
2. Slimming. Numerous studies have shown that when people switch from a diet rich in trans fats and saturated fats to a diet rich in foods containing unsaturated fats, people experience weight loss.
3. Improvement in patients suffering from rheumatoid arthritis. This diet helps to alleviate the symptoms of this disease.
4. Reduce belly fat. According to a study published by the American Diabetes Association, a diet rich in monounsaturated fats can reduce belly fat more than many other types of diets.

Polyunsaturated fats and their impact on health

A number of polyunsaturated fatty acids are indispensable, that is, they are not synthesized by the human body and must be supplied from the outside with food. Such unsaturated fats contribute to the normal functioning of the whole organism, the construction of cell membranes, the proper development of nerves and eyes. They are essential for blood clotting, muscle function and performance. Eating them instead of saturated fatty acids and carbohydrates also reduces bad cholesterol and blood triglycerides.

Polyunsaturated fats have 2 or more carbon bonds. There are two main types of these fatty acids: omega-3 and omega-6.

Omega-3 fatty acids are found in the following foods:

• fatty fish (salmon, mackerel, sardines);
• flax seeds;
• walnuts;
• rapeseed oil;
• unhydrogenated soybean oil;
• flax seeds;
• soybeans and oil;
• tofu;
• walnuts;
• shrimp;
• beans;
• cauliflower.

Omega-3 fatty acids can help prevent and even cure diseases such as heart disease and stroke. In addition to lowering blood pressure, high-density lipoproteins, and lowering triglycerides, polyunsaturated fats improve blood viscosity and heart rate.

Some research suggests that omega-3 fatty acids may help reduce the need for corticosteroid medications in patients suffering from rheumatoid arthritis. There is also an assumption that they help reduce the risk of developing dementia - acquired dementia. In addition, they must be consumed during pregnancy and lactation in order to ensure normal growth, development and formation of the cognitive function of the child.

Omega-6 fatty acids promote heart health when consumed in place of saturated and trans fats and can be used to prevent cardiovascular disease. They are found in:

• avocado;
• papse, hemp, linseed, cottonseed and corn oil;
• pecans;
• spirulina;
• whole grain bread;
• eggs;
• poultry.

Unsaturated fats - food list

Although there are many supplements containing these substances, obtaining polyunsaturated and monounsaturated fatty acids from food is considered to be more beneficial for the body. About 25-35% of your daily calorie intake should come from fat. In addition, this substance helps to absorb vitamins A, D, E, K.

Some of the most affordable and healthy foods that contain unsaturated fats are:

• Olive oil. Just 1 tablespoon of butter contains about 12 grams of "good" fats. In addition, it provides the body with omega-3 and omega-6 fatty acids necessary for heart health.
• Salmon. It is very beneficial for cardiovascular health and is also an excellent source of protein.
• Avocado. This product contains a large amount of unsaturated fatty acids and a minimum of saturated ones, as well as nutritional components such as:

Vitamin K (26% of the daily requirement);

Folic acid (20% of the daily requirement);

Vitamin C (17% d.s.);

Potassium (14% d.s.);

Vitamin E (10% d.s.);

Vitamin B5 (14% d.s.);

Vitamin B 6 (13% of d.s.).

• Almond. An excellent source of monounsaturated and polyunsaturated fatty acids, it also provides the human body with vitamin E, which is essential for healthy skin, hair and nails.

The following table provides a list of foods with unsaturated fats and an estimate of their fat content.

Tips for replacing saturated fats with unsaturated fats:

1. Use oils like olive, canola, peanut, and sesame instead of coconut and palm.
2. Eat foods high in unsaturated fats (fatty fish) instead of meats that are higher in saturated fats.
3. Replace butter, lard, and vegetable shortening with liquid oils.
4. Be sure to eat nuts and add olive oil to salads instead of using foods that are high in bad fats (such as dressings like mayonnaise)

Remember that when you include foods from the list with unsaturated fats in your diet, you must stop eating the same amount of foods high in saturated fats, that is, replace them. Otherwise, you can easily gain weight and increase the level of lipids in the body.

Based on materials

• http://www.health.harvard.edu/staying-healthy/the-truth-about-fats-bad-and-good
• http://bodyecology.com/articles/6_benefits_monosaturated_fats.php
• https://www.sciencedaily.com/releases/2006/09/060925085050.htm
• https://www.dietaryfiberfood.com/fats/unsaturated-fat-list.php
• http://extension.illinois.edu/diabetes2/subsection.cfm?SubSectionID=46
• http://examples.yourdictionary.com/examples-of-unsaturated-fats.html

Saturated fatty acids (SFA), the most abundant in food, are divided into short-chain (4 ... 10 carbon atoms - butyric, caproic, caprylic, capric), medium-chain (12 ... 16 carbon atoms - lauric, myristic, palmitic) and long-chain (18 atoms carbon and more - stearic, arachidine).

Saturated fatty acids with a short carbon chain practically do not bind to albumin in the blood, are not deposited in tissues and are not included in lipoproteins - they are quickly oxidized to form ketone bodies and energy.

They also perform a number of important biological functions, for example, butyric acid is involved in genetic regulation, inflammation and immune response at the level of the intestinal mucosa, and also provides cell differentiation and apoptosis.

Capric acid is the precursor of monocaprin, a compound with antiviral activity. Excess intake of short chain fatty acids can lead to the development of metabolic acidosis.

Saturated fatty acids with a long and medium carbon chain, on the contrary, are included in lipoproteins, circulate in the blood, are stored in fat depots and are used to synthesize other lipoid compounds in the body, such as cholesterol. In addition, lauric acid has been shown to be able to inactivate a number of microorganisms, including in particular Helicobacter pylori, as well as fungi and viruses due to the rupture of the lipid layer of their biomembranes.

Myristic and lauric fatty acids strongly increase serum cholesterol levels and are therefore associated with the highest risk of atherosclerosis.

Palmitic acid also leads to increased lipoprotein synthesis. It is the main fatty acid that binds calcium (in the composition of fatty dairy products) into an indigestible complex, saponifying it.

Stearic acid, as well as short-chain saturated fatty acids, practically does not affect the level of cholesterol in the blood, moreover, it is able to reduce the digestibility of cholesterol in the intestine by reducing its solubility.

unsaturated fatty acids

Unsaturated fatty acids are classified according to the degree of unsaturation into monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs).

Monounsaturated fatty acids have one double bond. Their main representative in the diet is oleic acid. Its main food sources are olive and peanut oil, pork fat. MUFAs also include erucic acid, which makes up 1/3 of the composition of fatty acids in rapeseed oil, and palmitoleic acid, which is present in fish oil.

PUFAs include fatty acids that have several double bonds: linoleic, linolenic, arachidonic, eicosapentaenoic, docosahexaenoic. In nutrition, their main sources are vegetable oils, fish oil, nuts, seeds, legumes. Sunflower, soybean, corn and cottonseed oils are the main dietary sources of linoleic acid. Rapeseed, soybean, mustard, sesame oil contains significant amounts of linoleic and linolenic acids, and their ratio is different - from 2:1 in rapeseed to 5:1 in soybean.

In the human body, PUFAs perform biologically important functions associated with the organization and functioning of biomembranes and the synthesis of tissue regulators. A complex process of synthesis and mutual conversion of PUFAs takes place in cells: linoleic acid is able to transform into arachidonic acid with its subsequent inclusion in biomembranes or the synthesis of leukotrienes, thromboxanes, prostaglandins. Linolenic acid plays an important role in the normal development and functioning of the myelin fibers of the nervous system and retina, being part of structural phospholipids, and is also found in significant amounts in spermatozoa.

Polyunsaturated fatty acids consist of two main families: linoleic acid derivatives, which are omega-6 fatty acids, and linolenic acid derivatives, which are omega-3 fatty acids. It is the ratio of these families, subject to the overall balance of fat intake, that becomes dominant from the standpoint of optimizing lipid metabolism in the body by modifying the fatty acid composition of food.

Linolenic acid in the human body is converted into long-chain n-3 PUFAs - eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Eicosapentaenoic acid is determined along with arachidonic acid in the structure of biomembranes in an amount directly proportional to its content in food. With a high level of dietary intake of linoleic acid relative to linolenic (or EPA), the total amount of arachidonic acid included in biomembranes increases, which changes their functional properties.

As a result of the use of EPA by the body for the synthesis of biologically active compounds, eicosanoids are formed, the physiological effects of which (for example, a decrease in the rate of thrombus formation) can be directly opposite to the action of eicosanoids synthesized from arachidonic acid. It has also been shown that, in response to inflammation, EPA is transformed into eicosanoids, providing a finer regulation of the inflammation phase and vascular tone compared to eicosanoids, derivatives of arachidonic acid.

Docosahexaenoic acid is found in high concentrations in retinal cell membranes, which are maintained at this level regardless of dietary intake of omega-3 PUFAs. It plays an important role in the regeneration of the visual pigment rhodopsin. High concentrations of DHA are also found in the brain and nervous system. This acid is used by neurons to modify the physical characteristics of their own biomembranes (such as fluidity) depending on functional needs.

Recent achievements in the field of nutriogenomics confirm the involvement of omega-3 PUFAs in the regulation of the expression of genes involved in fat metabolism and inflammation phases due to the activation of transcription factors.

In recent years, attempts have been made to determine adequate levels of dietary intake of omega-3 PUFAs. In particular, it has been shown that for an adult healthy person, the consumption of 1.1 ... 1.6 g / day of linolenic acid in the food composition completely covers the physiological needs for this family of fatty acids.

The main dietary sources of omega-3 PUFAs are flaxseed oil, walnuts and marine fish oil.

Currently, the optimal ratio in the diet of PUFAs of various families is the following: omega-6: omega-3 = 6…10:1.

Major Dietary Sources of Linolenic Acid

Main dietary sources of omega-3 PUFAs

general characteristics

In today's world, life moves at a fast pace. Often there is not enough time even for sleep. Fast food, rich in fats, which is commonly called fast food, has almost completely won a place in the kitchen.

But thanks to the abundance of information about a healthy lifestyle, more and more people are drawn to a healthy lifestyle. However, many consider saturated fats to be the main source of all problems.

Let's figure out how justified the widespread opinion about the dangers of saturated fats is. In other words, should you eat foods rich in saturated fat at all?

From a chemical point of view, saturated fatty acids (SFA) are substances with single bonds of carbon atoms. These are the most concentrated fats.

EFAs can be of natural or artificial origin. Artificial fats include margarine, natural fats include butter, lard, etc.

EFAs are found in meat, dairy and some plant foods.

A special property of such fats is that they do not lose their solid form at room temperature. Saturated fats fill the human body with energy and are actively involved in the process of building cells.

Saturated fatty acids are butyric, caprylic, caproic, and acetic acids. As well as stearic, palmitic, capric acid and some others.

EFAs tend to be deposited in the body "in reserve" in the form of body fat. Under the action of hormones (epinephrine and norepinephrine, glucagon, etc.), EFAs are released into the bloodstream, releasing energy for the body.

Useful properties of saturated fatty acids, their effect on the body

Saturated fatty acids are considered to be the most harmful. But given that breast milk is saturated with these acids in large quantities (in particular, lauric acid), it means that the use of fatty acids is inherent in nature. And this is of great importance for human life. You just need to know what foods to eat.

And you can get a lot of such benefits from fats! Animal fats are the richest source of energy for humans. In addition, it is an indispensable component in the structure of cell membranes, as well as a participant in an important process of hormone synthesis. Only due to the presence of saturated fatty acids is the successful assimilation of vitamins A, D, E, K and many trace elements.

The correct use of saturated fatty acids improves potency, regulates and normalizes the menstrual cycle. Optimal consumption of fatty foods prolongs and improves the functioning of internal organs.

Products with the maximum content of SFA

In foods, these substances are found in the composition of fats of both animal and vegetable origin.

The content of saturated fatty acids in animal fats is usually higher than in vegetable fats. In this regard, a clear pattern should be noted: the more fat contains saturated fatty acids, the higher its melting point. That is, if we compare sunflower and butter, it immediately becomes clear that solid butter has a much higher content of saturated fatty acids.

An example of a plant-based saturated fat is palm oil, the benefits and harms of which are actively discussed in modern society.

An example of an unsaturated animal fat is fish oil. There are also artificial saturated fats obtained by hydrogenation of unsaturated fats. Hydrogenated fat forms the basis of margarine.

The most significant representatives of saturated fatty acids are stearic (for example, in mutton fat its content reaches 30%, and in vegetable oils - up to 10%) and palmitic (its content in palm oil is 39-47%, in cow - about 25%, soybean - 6.5%, and in lard - 30%) acid. Other representatives of saturated fatty acids are lauric, myristic, margaric, capric and other acids.

Alpha-linolenic acid is found in high amounts in flaxseed oil, pumpkin seeds, soybeans, walnuts, and dark green leafy vegetables. herring, sardines, salmon, halibut, perch, carp.

Most omega 6 fatty acids are found in animal fats and vegetable oils: soybean, pumpkin, linseed, corn, sunflower, but the largest source is safflower oil. As well as nuts, eggs, butter, avocado oil, poultry meat.

A bit about artificial products

The group of saturated fatty acids also includes such an “achievement” of the modern food industry as trans fats. They are obtained by hydrogenation of vegetable oils. The essence of the process is that liquid vegetable oil under pressure and at temperatures up to 200 degrees is subjected to the active influence of hydrogen gas. As a result, a new product is obtained - hydrogenated, having a distorted type of molecular structure. There are no compounds of this kind in the natural environment. The purpose of this transformation is not aimed at benefiting human health at all, but is caused by the desire to obtain a “convenient” solid product that improves taste, with good texture and a long shelf life.

Daily requirement for saturated fatty acids

The need for saturated fatty acids is 5% of the total daily human diet. It is recommended to consume 1-1.3 g of fat per 1 kg of body weight. The need for saturated fatty acids is 25% of the total fat. It is enough to eat 250 g of low-fat cottage cheese (0.5% fat content), 2 eggs, 2 tsp. olive oil.

The need for saturated fatty acids increases:

• with various pulmonary diseases: tuberculosis, severe and advanced forms of pneumonia, bronchitis, early stages of lung cancer;
• during the treatment of stomach ulcers, duodenal ulcers, gastritis. With stones in the liver, gall or bladder;
• with general depletion of the human body;
• when the cold season comes and additional energy is spent on heating the body;
• during pregnancy and lactation;
• the inhabitants of the Far North.

The need for saturated fat is reduced:

• with a significant excess of body weight (you need to reduce the use of EFAs, but not completely eliminate them!);
• with a high level of cholesterol in the blood;
• cardiovascular diseases;
• diabetes
• with a decrease in the energy consumption of the body (rest, sedentary work, hot season).

Digestibility of SFA

Saturated fatty acids are poorly absorbed by the body. The use of such fats involves a long-term processing of them into energy. It is best to use those products that have a small amount of fat.

Choose lean chicken, turkey, and fish for consumption. Dairy products are better absorbed if they have a low percentage of fat.

Interaction with other elements

For saturated fatty acids, it is very important to have an interaction with essential elements. These are vitamins that belong to the class of fat-soluble.

The first and most important in this list is vitamin A. It is found in carrots, persimmons, bell peppers, liver, sea buckthorn, egg yolks. Thanks to him - healthy skin, luxurious hair, strong nails.

An important element is also vitamin D, which ensures the prevention of rickets.

Signs of a lack of EFA in the body:

• disruption of the nervous system;
• insufficient body weight;
• deterioration in the condition of nails, hair, skin;
• hormonal imbalance;
• infertility.

Signs of excess saturated fatty acids in the body:

• a significant excess of body weight;
• atherosclerosis;
• development of diabetes;
• increased blood pressure, disruption of the heart;
• the formation of stones in the kidneys and gallbladder.

Factors affecting the content of SFA in the body

Avoiding EFAs puts an increased burden on the body as it has to look for substitutes from other food sources in order to synthesize fats. Therefore, the use of EFAs is an important factor in the presence of saturated fats in the body.

Selection, storage and preparation of foods containing saturated fatty acids

Following a few simple rules during the selection, storage and preparation of foods will help keep saturated fatty acids healthy.

1. If you do not have an increased energy expenditure, when choosing foods, it is better to give preference to those in which the capacity of saturated fats is low. This will allow the body to better absorb them. If you have foods high in saturated fatty acids, then you should just limit them to a small amount.

2. The storage of fats will be long if moisture, high temperature, and light do not get into them. Otherwise, saturated fatty acids change their structure, which leads to a deterioration in the quality of the product.

3. How to cook products with EFA? Cooking foods rich in saturated fats includes grilling, grilling, stewing, and boiling. It is better not to use frying. This leads to an increase in the calorie content of food and reduces its beneficial properties.

If you are not going to engage in heavy physical labor, and you do not have any special indications for an increase in the amount of EFAs, it is still better to slightly limit the intake of animal fats in your diet. Nutritionists recommend trimming excess fat from meat before cooking it.

Saturated fatty acids for beauty and health

The correct use of saturated fatty acids will make your appearance healthy and attractive. Gorgeous hair, strong nails, good eyesight, healthy skin - all these are integral indicators of a sufficient amount of fat in the body.

It is important to remember that EFA is an energy that is worth spending in order to avoid the formation of excessive "reserves". Saturated fatty acids are an indispensable component of a healthy and beautiful body!

Benefits or harms of saturated fats

The question of their harm remains open, since no direct connection with the occurrence of diseases has been identified. However, there is an assumption that excessive consumption increases the risk of a number of dangerous diseases.

In what ways can they harm?

If the daily intake of carbohydrates is more than 4 grams per kilogram of body weight, then you can observe how negatively saturated fatty acids affect health. Examples confirming this fact: palmitic, which is found in meat, provokes a decrease in insulin activity, stearic, present in dairy products, actively contributes to the formation of subcutaneous fat deposits and negatively affects the cardiovascular system.

Here we can conclude that an increase in carbohydrate intake can turn "saturated" foods into the category of unhealthy.