Saturated fats in which foods. Unsaturated fatty acids in foods

This article is purely theoretical. However, it is important for understanding the need to include saturated and unsaturated fats in your diet for everyone who leads an active lifestyle (plays sports).

All fats can be divided into two large groups:

• Saturated - predominantly animals, usually solid;
• Unsaturated – predominantly vegetable, usually liquid.

The differences between them lie in the chemical structure. We will not go into the jungle of scientific terminology, we will only note that the sign by which a particular fatty acid is classified as either saturated or unsaturated is the number of bonds between carbon atoms and other atoms in the fatty acid molecule. The valency of carbon (that is, the number chemical bonds with other atoms) is equal to IV. Take a look at the picture:

If carbon atoms have one bond on each side, then they are called saturated, if double (or triple) are present, then the entire chain is called unsaturated.

The various omega-3, omega-6 and omega-9 labelings merely indicate where in the molecule the double (or triple) bond is present.

The most logical question: why do fats with a single or double (triple) bond exist? The fact is that the double bond in unsaturated fats provides free space in the molecule, giving it the ability to enter into chemical reactions and change the structure.

In other words, the free space allows the unsaturated fat molecule to selectively add various other molecules to itself, thereby changing its chemical properties and general structure the substance (tissue) in which they are included. In this sense saturated fats"chemically inert".

This fact is very important for plants. They cannot move (they have no locomotion function), so when unfavorable conditions V environment(reducing the amount sunlight, temperature fluctuations) they need to somehow secure their existence (survive). Plants change the composition of their fat, and it becomes dense, thereby retaining heat and protecting them from the cold.

In animals, everything is completely different: their fat cannot be modified, since it has a single carbon bond. But animals have the function of locomotion (they can move). Therefore, when unfavorable external conditions the animal can simply change its habitat (hide in a hole, hibernate, or “fly south”). Instead of changing the state of the fat cells, the animal simply moves into a different environment.

However, one should not think that animals only have saturated fat, and plants only have unsaturated fat. Both types of lipids are present in both the animal body and plants, but only the corresponding ones dominate.

So, for example, in 100 ml sunflower oil contains approximately 15% saturated fatty acids, i.e. as much as 15 ml. As a rule, it is 10-11% palmitic and 4-5% stearic acid.

At the same time in 100 grams lamb fat as much as 35% oleic acid, which is entirely unsaturated fatty acids. All this in Once again proves the inconsistency and incompetence of advice related to limiting saturated and animal fats in the diet.

In addition to the above classification, unsaturated fats are divided into:

• Monounsaturated fatty acid– MUFA;
• Polyunsaturated fatty acids – PUFAs.

They differ in the number of double (triple) bonds. In MUFA there is only one such bond, but in PUFA there are several of them. On this moment It is polyunsaturated fatty acids that are called the most beneficial of all unsaturated fats.

Saturated fats are increasingly discussed due to the impact they have on human health. This increased attention arose since they became part of many food products, especially confectionery products. Previously people knew that any diet should contain vitamins, proteins, carbohydrates and fats. However, today they have begun to abandon the latter en masse. But it wasn’t just that they were used in the past. What happened?

What do fats do in the body?

Biologists, nutritionists, food scientists, and even ordinary housewives who understand cooking know that the body cannot be healthy if it is not given timely necessary elements, especially proteins, carbohydrates and fats. In this article we will only talk about fats, although this does not mean that they are more important than the other two elements. We’ll just leave proteins and carbohydrates for separate studies.

So, fats. In chemistry they are called triglycerides, which belong to the class of lipids. These elements are part of the membrane, which allows cells to pass other substances. Lipids also provide enzyme activity nerve impulses, muscles, create connections for different cells and participate in processes necessary for the functioning of the immune system.

Among the known functions that fats perform in the body, we highlight energy, heat insulation and protection. Without fats, there will be no energy to create proteins and other complex molecules. The body will not be able to absorb fat-soluble vitamins and carry out many other chemical processes.

Fats and lifestyle

Humans need fats. But it is important to remember that the body must use them, and not accumulate them. How more active image life, the more lipids are consumed. The modern rhythm of life is less and less conducive to activity - sedentary or monotonous work, relaxing on the Internet or in front of the TV. We rarely walk home, more often on public transport or car. The result is that the body does not need the energy it receives from fats, which means they remain untouched and accumulate.

A sedentary daily routine is complicated by a fat-rich diet. The ever-accelerating pace of life does not give people the opportunity to eat in a relaxed home environment. You have to snack on fast food in eateries or products from the confectionery industry on the go. These types of foods supply the body with a lot of lipids, as well as foods containing saturated fats. They do harm.

Fats in detail

By chemical features Lipids are divided into two categories - saturated and unsaturated fats. The former molecule has a closed structure. It is unable to attach other atoms to itself. The chain of unsaturated fats has open carbon atoms. If there is only one such atom in the chain, then the molecule is called monounsaturated. There are also chains in which several carbon atoms have free space. These are polyunsaturated molecules. Why do we need all these chemical details?

The fact is that it is the ability of the chain to attach other atoms to itself that makes the fat entering the body useful. What is its use? The fact is that these free spaces create conditions for the formation of new molecules. Free carbon atoms in fats add other elements to themselves, after which the new chain becomes more necessary and beneficial for the body. Saturated fats do not have this ability, so the body cannot use them for other purposes. Because of this, when there is excess intake, they accumulate.

Cholesterol should be your friend

Saturated fats have another feature that makes them outcasts. They contain cholesterol. As soon as they heard this word, many immediately thought about vessels, overweight, cardiac muscle. Yes, unfortunately, there are consequences modern image life has made cholesterol an enemy for many.

However, this molecule is not always harmful. Moreover, our body needs it so much that it produces it itself. For what? Without cholesterol, the process of creating many hormones (cortisol, testosterone, estrogen and others) is impossible. In addition, this organic compound is involved in complex intracellular reactions, on which the activity of the entire cell, and therefore the entire organism, depends.

The Journey of Cholesterol

The human body is supplied with cholesterol in two ways - produced in the liver and supplied through fats. Saturated and unsaturated lipids supply cholesterol to different connections. The fact is that this substance does not dissolve in water. It enters the blood along with lipoproteins. These molecules have a complex structure and a very diverse composition.

Low-density lipoproteins are already loaded with cholesterol. They simply move with the blood throughout the body and are used by those cells that lack this substance. These lipoproteins are found in saturated fats.

If cholesterol enters the body in the form of lipoproteins with high density, then there is more benefit. These elements contain little cholesterol and are able to add it. Therefore, approaching those cells that have excess cholesterol, they take it and transfer it to the liver. There it is processed and removed from the body. Such lipoproteins are found more often in unsaturated fats.

Don't Skip Fatty Acids

Excess of unused lipids and cholesterol in the body leads to very serious diseases. An important factor good health is nutrition. Care must be taken not to enter the body with food. large quantities saturated fats. What products contain them?

All lipids are very complex in composition. It cannot be stated unequivocally that only animal or only plant foods consist of certain substances. Saturated fats are found in both animal and plant foods. Meat, lard, and butter are carriers of saturated lipids of animal origin. If we talk about carriers plant origin, then these are cocoa (its oil), coconut and palm (their oils).

Animal Fatty Acid Sources

Saturated animal fats contain everything fat soluble vitamins(A, C, carotene, D, B1, E, B2). However, the cholesterol content in them is very high (in oil - 200 mg/100 g, in lard - 100 mg/100 g). It is advisable to consume these fats in limited quantities - no more than 70 grams per day.

The best way out is to replace animal lipids with plant lipids consisting of unsaturated fatty acids. Butter is replaced with olive oil (this is the most The best decision, since this product does not contain “bad” cholesterol at all), flaxseed or sunflower. Meat is replaced with fish.

Remember: saturated fats are high-calorie foods. If you indulge in meat, fries or a hamburger during the day, be sure to walk a few stops on your way home. This is the easiest way to use up the lipids you eat.

Plant sources of harmful lipids

Saturated fats are vegetable oils. A very unusual phrase. More often we are used to hearing that they replace fatty acids. Yes, they did that before. Today this is also practiced, especially in the confectionery industry. Just replace the butter with palm oil. This is a very worrying trend.

Palm and coconut oil- These are saturated fats. Which products don't have them? Only those prepared at home. If you eat in public catering, then you will not be able to avoid consuming unhealthy fats.

Many manufacturers add either cheap Palm oil(instead of expensive animal fats), or artificial trans fats. The latter is a masterpiece of cynicism Food Industry. To increase the shelf life of products and make them cheaper, food scientists take chains of unsaturated fats and add oxygen to them (in the free spaces of the molecule). As a result, the chain loses its useful features turns into solid vegetable fat, which is convenient for use, but very useless for the body. The cells don't know what to do with it and just accumulate it.

Unsaturated fatty acids are present in all fats consumed in food, but the largest amount of them is found in vegetable oils, which remain liquid at room temperature, are perfectly absorbed by the body, bringing a lot of useful substances to it, incl. fat-soluble acids. These fats contain high oxidation capacity due to the presence of double unsaturated bonds. The most commonly used are linoleic, oleic, arachidonic and linolenic acid. Nutritionists insist that daily diet these acids must be present.

On one's own human body does not produce unsaturated fats, so they must be introduced with food daily. Only arachidonic acid, in the presence of a sufficient amount of B vitamins, can be synthesized by the body itself. All these unsaturated acids are needed to carry out vital biochemical processes in cell membranes and for intramuscular metabolism. The sources of all of the above acids are natural vegetable oils. If there is not enough unsaturated fat in the body, this leads to skin inflammation, dehydration and stunted growth in adolescents.

Unsaturated fatty acids are part of the membrane cell system, connective tissue and the myelin sheath, which allows them to participate in fat metabolism body and easily convert cholesterol into simple compounds that are easily removed from it. In order to meet the human need for unsaturated fats, you need to eat at least 60 grams of any vegetable oil daily. The biggest biological activity have corn, sunflower, flaxseed, cottonseed and soybean oils, which contain up to 80% unsaturated fatty acids.

The benefits of unsaturated fats

Unsaturated fats are divided into two types:

• Monounsaturated
• Polyunsaturated

Both types of fatty acids are beneficial for heart health. vascular system. They're lowering high level cholesterol in the blood. The only difference between them is that monounsaturated fats At room temperature they are liquid, but at low temperatures they begin to harden. Polyunsaturated - liquid at any temperature.

Monounsaturated fatty acids are mainly found in natural products such as nuts, olive oil, avocado, canola oil, grape seed oil. The most common is olive oil. Doctors advise to include it in your diet, as it brings great benefit for the health of not only the heart, but the entire body as a whole. This oil is generally considered ideal, since it does not lose its properties at any temperature, does not become saturated over time and does not granulate.

Polyunsaturated fats such as omega-3 (alpha) linoleic acid) and omega-6 (linoleic acid) is the one construction material, from which all are formed healthy fats in organism. Contained polyunsaturated fats in some cold-water species sea ​​fish eg in mackerel, herring or salmon. They are most useful when various inflammations to maintain immunity, prevent the occurrence of cancer cells and improve brain function. also in large quantities Omega-3 polyunsaturated fatty acids (PUFAs) are found in linseed oil, walnuts, V small quantity– in canola oil and soybeans. All of these products are needed by the body, as they contain decosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and alpha-linoleic acid, which is not produced by the human body on its own.

World Scientific research showed that omega-3 PUFAs can even stop the development of cancer, which is caused by the action of certain receptors in cells that stop the increased ability of cells to divide, especially brain cells. Also, omega-3 PUFAs have the ability to restore destroyed or damaged DNA and help reduce blood clotting, which improves blood flow, thereby eliminating various inflammations.

Daily consumption of unsaturated fats eliminates and prevents:

• Itching and dry skin
• Fatigue and chronic fatigue
• Depression
• Diseases of the cardiovascular system
• Brittle hair and nails
• Diabetes mellitus type II
• Painful sensations in the joints
• Poor concentration

Harm from unsaturated fatty acids

Excessive consumption of unsaturated fats can not only lead to premature aging, but also the spread of arthritis, multiple sclerosis and other chronic diseases. IN Lately the production of fish sticks, crispy potatoes, fried pies and donuts. It seems that they are produced using healthy vegetable oils, but the oil is subjected to heat treatment. In this case, the process of polymerization of fats and their oxidation occurs, as a result of which unsaturated fats break down into dimers, monomers and higher polymers, which reduces nutritional value vegetable oil and completely destroys the presence of vitamins and phosphatides in it. The least harm that food cooked in such oil can cause is the development of gastritis and irritation of the gastrointestinal tract.

Need for unsaturated fats

The amount of fat in the human body depends on age, climate, labor activity and state immune system. In northern climatic zones, the need for unsaturated fats can reach up to 40% of calories per day from food consumed, respectively, in southern and middle climatic zones - up to 30% of daily calories. Daily ration for older people is approximately 20% of total number food, and for people engaged in heavy physical labor - up to 35%.

To avoid serious problems health, you need to:

• Instead of chocolate and sweets for dessert, eat nuts and grains
• Instead of meat, eat fatty sea fish three times a week
• Completely remove from the diet fried food and fast food
• Consume vegetable oils raw: olive, flaxseed or canola oil.

Now no one doubts that it is impossible to completely remove fats from your diet, either for weight loss or gain. muscle mass. Many of the fats are very necessary and healthy.

Thanks to high calorie content fats are an excellent source of energy. In addition to glycerol, they contain fatty acids, which largely determine biological value food products.

Some vitamins cannot be active unless they are dissolved in fat.

Functions of fatty acids

Fatty acids are components of phospholipids and glycolipids that make up the structure of cell membranes.

Fatty acids are components of triacylglycerides (neutral fats), the main source of energy in the body, stored in adipose tissue. Cm. .

About 70 different fatty acids are found in the human body. Of these, the most common are about 20. All of them contain unbranched chains built from an even number (12 - 24) of carbon atoms. Among them, the predominant acids are those with 16 and 18 carbon atoms in the chain, C16 (palmitic) and C18 (stearic, oleic and linoleic).

Fatty acids are divided into two groups: saturated and unsaturated, depending on their chemical nature.

There is an opinion that only unsaturated fats (the source of which are mainly vegetable oils) are healthy, and animal fats with saturated fatty acids should be avoided. But this is a very controversial and unsafe position. After all, saturated fats are very important in the body.

Unsaturated fatty acids

Unsaturated (unsaturated) fatty acids are acids whose structure contains one or more double bonds between adjacent carbon atoms. Moreover, chemically these double bonds in almost all cases are cis double bonds (not trans). This is a very important structural difference that makes fatty acids active and beneficial.

What does this mean and how can we benefit from it?

With the help of regular double unsaturated bonds, acids have high oxidative reactivity. This is used by the body to renew cell membranes, regulate their permeability, and synthesize regulators immune defense and other biologically active substances.

There can be different numbers of double bonds: if such a bond is present in a single copy, then the acid is called monounsaturated (Omega-9, oleic acid).

If there are several double bonds, the acids are called polyunsaturated. These include Omega-3 (linolenic) and Omega-6 acids (linoleic and arachidonic).

Unlike Omega-9 polyunsaturated acids are not produced by the human body and must be supplied with food.

Products with unsaturated fatty acids

The only animal fat that falls into this category is fish fat.

Products containing monounsaturated acids harden when cooled slightly. This can be seen with olive oil if you put it in the refrigerator.

Saturated fatty acids

Saturated (marginal) fatty acids are those fatty acids that do not have double bonds in their structure. They are considered the most harmful; it is on them that all the harm of fats is blamed: from atherosclerosis to obesity.

With them excessive By consuming it you can actually develop a whole “bouquet” of various diseases.

But you shouldn’t be so afraid of them that you shouldn’t completely remove them from your diet - after all, they are involved in the synthesis (including testosterone), the transfer and absorption of vitamins and microelements, and are also a source of energy. It is important to note that a lack of animal fats in a woman’s diet can lead to hormonal imbalance, and in as a last resort and to infertility.

Foods with saturated fatty acids

Products, with high content saturated fats, usually of animal origin: butter, cream, milk, fatty varieties meat. There is a pattern - the more saturated acids a product contains, the more difficult it is to melt it, to bring it from a solid to a liquid state. For example, you can easily guess where there are more saturated acids - in vegetable or butter.

From plant products Coconut oils also contain a lot of saturated fats, but there is still fierce debate about their benefits or harms. But, despite this, they are actively added in large quantities to various cheap products and surrogates. Their health benefits are questionable.

For better digestibility of animal fats, they are melted (for example, used for frying). Their digestibility increases not only when melted, but also if they are turned into an emulsion. Thus, fatty acids from milk, butter, and cream are better absorbed by the body than from a piece of lard.

If eaten cold healthier products vegetable origin with unsaturated fatty acids, it is recommended to cook with animal fats. When heated, the double bonds of oils will undergo intense oxidation. There is an opinion that at this time carcinogenic substances are formed, which, when accumulated in the body, cause cancer.

How much fat does a person need?

IN Everyday life You should consume about 1 g of fat per kg of body weight per day. That is, if you weigh 65 kg, then you will get 65 g of fat.

Half of the fatty acids consumed per day should be of an unsaturated nature (vegetable oils, fish oil).

There is no need to eat fats specifically - they can be obtained from familiar products. A fatty foods(the same oils) should be consumed in minimal quantities.

When losing weight, you can reduce the amount of fat to 0.8 g per kg of body (but not less than 30 g of fat per day). At the same time, you should calculate the amount of fat not by your existing body weight, but by the desired weight that you will have without excess fat (one way to find out the % of fat is using special scales).