Lipids – What are they, foods, types and what they are for

Lipids – What they are, Foods, Types and What they  are for are fundamental information that we all need to know. Furthermore, Lipids together with carbohydrates, proteins and nucleic acids are one of the four main classes of biologically essential organic molecules present in all living organisms; its quantity and quality in the diet are able to influence cell, tissue and body physiology as a whole.

Fats, also called lipids , are necessary substances for our body. It is important to know, however, that not all types are good for the human body. However, some of them can seriously harm our health.

That’s why we decided to offer an overview of the main types of lipids  that exist, formed according to the way in which the molecules fuse in them. So, let’s see more about Lipids: What they are, Foods, Types and What They Are For:

What are Lipids?

Lipids is a term derived from the Greek “lipos”, meaning fat, they are a heterogeneous group of substances that have in common a low degree of solubility in water , but at the same time show, however, soluble in organic solvents such as benzene, ether or chloroform. We tried not only to think about Lipids  at the table, but more generally, also from a chemical point of view.

Known as fat, they are divided into three types, simple, compound and derivatives. The simplest ones, then, are composed mainly of triglycerides – the most present fats in our body – and are the main fat deposit in adipose cells. Incidentally, fatty acids are also present in simple lipids  , which are subdivided into saturated and unsaturated.

Where do lipids come from?

Excess carbohydrates in the diet  are converted to triglycerides, which includes fatty acid synthesis from acetyl-CoA in a treatment known as lipogenesis and takes place in the endoplasmic reticulum. In animals and fungi, single multifunctional buds of a protein over the course of these treatments, while bacteria use multiple separate enzymes. Thus, some types of unsaturated fatty acids cannot be synthesized in mammalian cells and therefore must be consumed as part of the diet , like omega-3 .

Acetyl-CoA is also involved in the mevalonate pathway, which is responsible for producing a wide range of isoprenoids, which include important lipids such as cholesterol and steroid hormones.

How Lipids Are Divided:

Among the lipids that can be distinguished are simple, complex and modified.

Simple:

Simple lipids  are present in a high percentage in our body and in our diet , playing an energy reserve role . Therefore, these include the previously described triglycerides and waxes.

Complexes:

Complex lipids , on the other hand, are substances that are also made of other chemical elements (phosphoric acid, sugars, amino alcohol) and perform special functions within our bodies. These include phospholipids, glycolipids and lipoproteins.

Among the modified lipids  (also previously analyzed) belong: steroids, vitamins, cholesterol , etc. Incidentally, there is also a precise division of Lipids  based on their composition.

Unsaturated fatty acids:

Unsaturated fatty acids are composed of one or more double bonds between carbon and hydrogen. Therefore, these have a low melting temperature and are mainly vegetable fats .

Saturated Fatty Acids:

Saturated fatty acids are compounds without double bonds. So these have a high melting point and are mostly animal fat (although you can find them in some vegetable oils like palm oil).

Monounsaturated Fatty Acids:

Monounsaturated fatty acids are fats that, thanks to their composition, are easily used by our body and “replace” the cholesterol  present in the blood. So, they are found in foods like dried fruit, olive oil, or in some types of fish.

Polyunsaturated Fatty Acids:

Polyunsaturated fatty acids are also considered good fats, including omega-3 , omega-6 and omega-9 . Thus they are present in fish, nuts and some plant extracts.

Essential Fatty Acids:

Essential fatty acids are lipids  that must be introduced through the diet and are essential to ensure the body is in good health. So among these are omega-3 and omega-6.

Hydrogenated Fat Acids:

Hydrogenated fatty acids are fats that are harmful to our body. So, they are formed by hydrogenated fats of vegetable origin (unsaturated). Incidentally, these are easier to store and have a lower cost in the food industry, one such product consisting of hydrogenated fats is margarine .

Hydrolyzable and Non-Hydrolyzable Lipids:

Lipids that contain an ester functional group are hydrolyzable in water . After all, these include neutral fats, waxes, phospholipids and glycolipids. Fats and oils are composed of triglycerides, composed of glycerol (1,2,3-trihydroxypropane) and 3 fatty acids to form a triester. Triglycerides are found in the blood and are stored in fat cells. Thus, complete hydrolysis of triacylglycerols yields three fatty acids and one glycerol molecule.

Non- hydrolyzable lipids lack these functional groups and include steroids and fat-soluble vitamins (A, D, E and K).

The Functions of Lipids:

Lipids are used directly, or are otherwise synthesized, from dietary fats . Thus, there are numerous biosynthetic pathways to break down and synthesize lipids  in the body. They have many different tasks, all important within the body:

• They are a concentrated source of energy;
• Makes food more appetizing;
• Satisfies appetite for a long time;
• Accumulates fat-soluble vitamins;
• They act as thermal insulation for the body;
• They are structural components of all nerve and brain cells;
• They are nutrients with certain organic functions;
• They are biomolecules.

As described above, Lipids  perform important functions and therefore must be taken correctly in your  daily diet . Therefore, to have a healthy, complete and above all balanced diet  and allow the development of the organism in childhood and adolescence.

Foods Rich in Lipids:

It is advisable to prefer unsaturated fats (therefore of vegetable origin), because they tend to lower the cholesterol level . Incidentally, unsaturated fatty acids can perform their useful function in the body only in the presence of vitamin E (tocopherol) contained in:

• Vegetable oils ( peanut , soy , corn, palm, sunflower, etc.);
• Wheat germ;
• Nuts ;
• seeds;
• Whole grains;
• Green leafy vegetables.

Among the foods rich in saturated lipids  that should be limited, we find those of animal origin, such as:

• Whole milk products;
• butter ;
• Meat with fat;
• Fat cheeses;
• Salami or sausages;
• Creme;
• Ice cream;
• Coconut oil ;
• Palm oil.

An excess in consumption of these foods can greatly increase  LDL (bad) cholesterol levels.

Foods that contain monounsaturated fats are of plant origin, such as olive oil . Therefore, they are beneficial for the body.

Foods with a high content of polyunsaturated lipids  include:

• Fish;
• Fish , sunflower, corn and soy oils ;
• Nuts ;
• Almonds;
• chestnuts;
• flax seeds ;
• Chia and sesame.

Including these foods in the diet  is a healthy habit.

Both foods rich in monounsaturated and polyunsaturated lipids  are allies for the reduction of LDL cholesterol and for the increase of HDL  (good) cholesterol. Thus, its inclusion in the diet  reduces the risk of cardiovascular disease.

Lipid digestion:

It takes time to digest lipids  and a certain effort is also required for our body due to the fact that these substances are insoluble in water and have a complex structure. Digestion of fats starts in the stomach with an enzyme called gastric lipase that acts as it can, limited by the high acidity of the stomach. The lipids then continue on their way and their complete digestion takes place in the small intestine.

In the duodenum, a subsection of the small intestine, lipids interact with bile secreted from the gallbladder, transforming them into smaller particles. Thus, reducing fat particles allows enzymes to break them down to break them down into progressively smaller particles.

Therefore, if we take the example of triglycerides, in the digestive process they are first converted into diglycerides, then into monoglycerides and finally into fatty acids and glycerol.

How Much Lipids Should We Eat Daily?

It is agreed that the ideal amount of lipids  in the diet  is 25 to 35% of the total caloric intake. As stated so far, it must not exceed the upper limit, but also not fall below the minimum value, and because it would be in nutritional deficiencies, because the diet  would become so inadequate as to be easily abandoned.

As for cholesterol , it is recommended not to take more than 300 mg per day. Finally, in the presence of cardiovascular diseases or high family predisposition to these diseases, cholesterol intake  should be lower.