Lipids – Fat

Lipids: characterize biomolecules that do not dissolve in water but only in organic solvents (ether or chloroform) with low polarity. From a chemical point of view, they can belong to many categories of organic compounds, but here we will focus on the combinations of animal and plant organisms.

They are obtained from plant or animal raw materials by extraction and in the presence of ether. Unlike carbohydrates, which all have a similar structure, lipids include compounds with entirely different structures.

Fatty acids are divided into:

• Monounsaturated, the existence or not of a double bond in their molecule (1 double bond)

• Polyunsaturated (two or more double bonds)

• Saturated (no double bond) and the structure of the double bond in "cis" (cis) and "trans" (trans) fatty acids.

The human body uses lipids as:

Energy stores

The human body stores carbohydrates, glycogen or starch, a source of quick access to energy production. However, storing lipids (triglycerides) is more important because it gives a much more significant amount of energy than carbohydrates.

Building materials

The bilayer of each cell's cell membrane is formed from lipids (phospholipids, cholesterol).

Messengers

Steroid hormones are lipids that organisms use to transmit messages. Lipids include many classes of compounds, but here we will look at the most basic ones, which are triglycerides, phospholipids (lecithin), sphingoglycolipids (brain components) and steroids (cholesterol).

Here we are referring to fats (such as cholesterol) from the diet, which can be stored in adipose tissue (body fat). Lipids are broken down into smaller components called fatty acids and used for energy. Therefore, lipids are simple chains of fatty acids that are joined together.

The role of lipids in the body

1. Lipids are used by the body to build cell membranes, and they are the main structural component of cell membranes.

2. They store the sugars in the so-called fat stores, which are also the body's energy stores, offering humans 30-35% of energy.

3. They participate in the protective coverings of the organs as insulators (help to keep the body temperature constant)

4. They take part in the mechanisms of immunity.

5. Hormone production, vitamins A, E, and K, sex hormones and adrenal hormones belong to lipids.

6. Some lipids form compounds of great biological importance, with proteins (lipoproteins) and sugars (glycolipids) forming a structural component of cell membranes.

The main functions of lipids

1. Energy production and storage. Fat is the ideal raw material for energy production since each gram yields 9 kcal, in contrast to carbohydrates and proteins, which produce 4 kcal.

2. It protects vital organs such as the heart, liver, kidneys, spleen, brain and spinal cord. It also insulates the body, thus reducing the loss of heat, resulting in an increase in each person's resistance to fluctuations in temperature, especially to the cold.

3. They act as solvents for fat-soluble vitamins and help transport these fat-soluble vitamins: A, E, D, and K.

4. They help suppress hunger. Due to their chemical structure, stomach emptying is delayed up to 3.5 hours after digestion, and the stay of fat in the stomach cavity results in the delay of hunger phenomena.

Triglycerides

It is one of the basic lipids found in food and is the form par excellence in which the body stores this fat in adipose tissue to use during fasting as energy.

Triglycerides are organic compounds whose structure consists of a glycerol molecule (as a major carrier) attaching 3 fatty acids (fatty acid esters and glycerol), hence the name.

The breakdown of lipids and triglycerides in food occurs in the intestine and then in the periphery, where more extensive processing takes place before they reach their final destination, the liver. They yield free fatty acids stored as fat when not used for energy production.

1. Unsaturated fats = Healthy (good) fats

Which we mostly find in plants than in animals and are usually in liquid form, and we consider them healthier. Which are divided into two other subcategories such as:

• Monounsaturated: with or without a double bond in their molecule = 1 double bond.

• Polyunsaturated: fats with two or more double bonds, as well as Omega 3 & 6 fats.

It is important to know!

• Polyunsaturated fatty acids are often called omega-3, omega-6, and long-chain fatty acids.

• Linolenic (ALA), eicosapentaenoic (EPA), docosahexaenoic (DHA) or omega-3 fatty acids, linoleic (LA) or omega-6 fatty acid & arachidonic acid (ARA) are fatty acids that the human body cannot synthesizes them or synthesizes them in minimal amounts and therefore should be obtained through the diet.

2. Saturated & Trans fats = Unhealthy (bad) fats

No double bond and the structure of the double bond in "cis" CIS and "trans" TRANS fatty acids.

• CIS = on the same side

• TRANS = on the other side (in Latin, it's the term for arranging the two subgroups based on molecular placement).

The saturated ones, which for the most part we find in animals (with minimal exceptions such as coconut oil) and are in solid form and are not considered so healthy, are:

• Lauric acid

• Myristic acid

• Palmitic acid

• Stearic acid

• Arachidic acid

Trans fats are the fatty acids that occur naturally in some foods or result from industrial hydrogenation — solidification or heating oils at high temperatures (frying).

In general, however, fats are molecules that provide large amounts of energy when burned, which is the main reason for the body to store them and use them only in an emergency.

Unsaturated Fats

These healthier fats are generally found in plant foods such as fruits, seeds, nuts and vegetables. They can be divided into subcategories such as monounsaturated (MUFA / olive oil, rapeseed oil) fatty acids, and each of them should constitute about 1/3 of our total intake of fatty acids and polyunsaturated (PUFA / sunflower oil, soy, sesame oil and corn oil).

The unsaturated ones, which are usually in liquid form and we consider healthier, are:

• Palmitoleic acid

• Oleic acid

• Linoleic acid

• Linolenic acid

• Arachidonic acid

Unsaturated fatty acids with one double bond are called monounsaturated, while those with two or more double bonds are called polyunsaturated fatty acids. A small percentage of fatty acids are free, most of which are bound to other molecules to form triglycerides, phospholipids and sphingoglycolipids.

So, as we can see, triglycerides are also fats, with 3 fatty acid molecules in combination with a glycerol-alcohol molecule. Fatty acids are simple compounds (monomers), while triglycerides are complex molecules (polymers). The physical properties of triglycerides depend on the type of fatty acids they contain. Those composed of unsaturated fatty acids have lower melting points, while those composed of saturated fatty acids have higher melting points.

Monounsaturated fats

Chemically speaking, these are simple fats with a double (unsaturated) carbon bond in the molecule and are usually liquid at room temperature but begin to condense when cooled. Olive oil is an example of a type that contains monounsaturated fats.

Monounsaturated fats can benefit health when consumed in moderation and when used to replace saturated or trans fats, as we mentioned. Still, they can also help lower bad cholesterol in the blood and lower the risk of heart disease and stroke. They can also provide nutrients and help grow and maintain body cells. Monounsaturated fats are also high in the antioxidant vitamin E.

Several foods also high in monounsaturated fats include vegetable oils such as olive oil, peanut oil, sunflower oil, canola oil, and sesame oil. Other sources besides liquid unsaturated fats include avocados, nuts, seeds and even peanut butter.

Peanut butter, which in essence is nothing more than a mass of peanuts under a centrifugal process, brings the oils of the fruit to the surface, creating a solid group with a very high content of unsaturated fats because a single spoon has concentrated much more peanuts than that we can consume in their primary form. For this reason, we should have moderation in its consumption and take care if possible to do it ourselves as correctly as possible, the more its benefits.

Polyunsaturated fats

Chemically speaking, polyunsaturated fats are fats with more than one carbon double bond (unsaturated) in the molecule. Polyunsaturated fats are usually liquid at room temperature but remain liquid even when they come in contact with simple cooling - refrigerator. Most foods contain a combination of lipids and include several vegetable oils, such as soybean oil and corn oil, and fatty fish, such as salmon, herring trout, pollock and mackerel. Other sources include nuts and seeds such as walnuts and sunflower seeds.

Polyunsaturated fats can benefit health when consumed in moderation and used to replace saturated or trans fats. They can also help lower blood cholesterol levels and reduce the risk of heart disease. They also include the essential fats that cover the needs of the body but cannot produce a synthesis, such as omega 3 & 6 fats, which play a decisive role in the functioning of the brain and in the average growth and development of the body, which is why they must to be taken through food.

Fat is necessary for the proper functioning of the body. Fats provide essential fatty acids, which are not made by the body and must be obtained from food, and these essential fatty acids are:

• Linoleic Acid (CLA)

It is mainly found in milk, dairy products, meat and meat products of ruminants. Linoleic acid (CLA) inhibits the growth and spread of malignant tumours, mainly by affecting and suppressing the productive replication of cells and the mechanisms of carcinogenesis.

It also has anti-inflammatory, anti-arthritic, anti-cancer and anti-diabetic properties. At the same time, it is essential for the health and elasticity of the skin, as well as for the healthy appearance of the nails. On the other hand, it has been shown that CLA can cause insulin resistance, reduce body fat levels and help increase body fat mass.

One of the omega-6 fatty acids, Gamma Linoleic Acid (GLA), is worth mentioning, mainly found in evening primrose oil (evening primrose oil or EPO) and borage oil.

• Alfa Linoleic Acid

Alpha-linolenic acid is a type of omega-3 fatty acid found in plants such as flaxseed, soybeans, walnuts, perilla (oil) and canola, as well as in seaweed which is this and is similar to the omega-3 fatty acids that are found in fish oil, and which are found in fatty fish such as mackerel, salmon, herring, fresh tuna and sardines.

When we take in alpha-linolenic acid (ALA) from our diet, it is converted into eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are more accessible for our body to use.

Omega-3 fatty acids - mainly EPA and DHA - have been shown to reduce inflammation and may help prevent chronic diseases such as heart disease and arthritis. They may also be necessary for brain health and development and average growth and development. There is strong evidence that fish oils containing EPA and DHA may help treat heart disease, prevent heart attack and stroke, and slightly reduce high blood pressure. With omega-3 fatty acids, they can have better antithrombotic and cardioprotective action.

Finally, it is worth mentioning a fatty acid, oleic acid (omega-9), which, together with the antioxidants of virgin olive oil, has a very beneficial effect on the cardiovascular system. At the same time, there are indications that it reduces the risk of cancer, especially of the rectum, colon, breast, prostate, pancreas and endometrium.

• Linolenic Acid

It is an unsaturated omega-3 acid, colourless at room temperature, and chemically it is a carboxylic acid with 18 carbon chains and 3 "cis" double bonds. It is an essential fatty acid and an organic compound found mainly in seeds (Chia, flaxseed, walnuts) and many vegetables.

• Gamma Linolenic Acid (GLA)

It is the oil of black gooseberry, borage and eranthemum. Gamma Linolenic Acid (GLA) is a fatty acid of the omega-6 series with great therapeutic value since it is the precursor of the substance prostaglandin E1 (PGE1) that our body uses to deal with inflammation and to defend itself against diseases, such as cancer, heart disease, allergies, asthma, arthritis and auto-immune as well as to avoid premature ageing.

GLA can be produced in our body from linoleic acid, which should generally be sufficient in our diet.

• Arachidonic acid

Arachidonic acid helps facilitate the growth of muscle tissue around the skeleton, helps form hormones, and increases protection against pathogens. It is mainly found in a variety of red meats, as well as egg yolks and meat organs. It can also be added to processed foods as a supplement for vegetarians or vegans.

People with an arachidonic acid deficiency may not be able to grow correctly or may have difficulty fighting infections. However, too much arachidonic acid can lead to specific health risks, such as cardiovascular problems. It is helpful to have a supply of omega-3 fatty acids in fish oil, often used to boost brain power and other health goals.

Saturated fats

There is a heated debate about how bad saturated fat is for our health. Recently, several studies appeared to suggest that eating diets high in saturated fat did not increase the risk of heart disease, a finding that contradicted decades of dietary advice. Researchers examined the relationship between saturated fat intake and coronary heart disease (CHD), stroke and cardiovascular disease (CVD).

Their conclusion was controversial. There is insufficient evidence from exploratory epidemiological studies to conclude that dietary saturated fat is associated with an increased risk of coronary heart disease, stroke, or cardiovascular disease. But this is a grossly oversimplified and erroneous interpretation that we would do well not to take too seriously.

The other day I read a study with a very complex message and a very inspiring and thorough interpretation which referred to this burning issue, and it was as follows:

Cutting saturated fat can be good for health if people replace saturated fats with good fats as much as possible, especially polyunsaturated fats.

Of course, I would like to add that the combinations of saturated fats are the ones that, unfortunately, give saturated fats a bad name. The worst variety is processed carbohydrates, and simple ones such as sugar, pasta, cereals and breads, and such combinations bring the worst health results.

Trans Fatty Acids

From a chemical point of view, trans-fatty acids are the type of unsaturated fats with a somewhat eccentric character which can be created artificially. In food production, liquid unsaturated fats (such as vegetable oils) are catalytically hydrogenated to produce a partially or fully saturated fat, which can melt at a desired temperature between 30° & 40°C.

• Steroids

These lipids, however, have a different structure from the rest of the lipids. These include sterols, bile acids, corticoids, androgenic hormones, estrogens, cardiac glycosides, etc. Four rings form the central part of the chemical structure of steroids, also called steroid rings. In animal organisms, cholesterol is the most abundant steroid.

Summary

Fats are an essential part of the human diet, and this is a given. The only thing left is to know how much and what kind of fats we should consume to be healthy!

But let's not forget that excessively low-fat consumption prices, especially when they come from some empty diets, can only harm the body because they reduce the amount and the absorption of fat-soluble vitamins and essential fatty acids in the diet.

All fats are not the same, so consuming the right amounts of fat groups is very important. That is, by reducing unhealthy saturated and especially trans fatty acids from our diet and replacing part of them with healthier unsaturated fats, we will achieve the best balance in the consumption of fats, which leads to the best health of the body.