The human body contains a myriad of vital molecules that are critical for maintaining the metabolic constancy of the body. Among these, lipids, as substances of the body primarily responsible for structural and regulatory functions, should be of particular significance; although the fundamental importance of lipids to the body is significantly broader. In this research paper, the goal is to examine in detail the phenomenology of lipids as vital molecules for the human body, their classification, and properties, including potential connections to health.
Background Information: Lipids
Like proteins and carbohydrates, lipids are essential bioactive compounds of the body, an existence without which does not seem possible. Standardly, lipids are regarded as glycerol derivatives in which the active hydrocarbons are replaced by fatty acid residues. An example of such a triglyceride is shown in Figure 1: it is a tristearin, in which three stearic acid residues have been added to the glycerol molecule — the carbons are highlighted in green. Such molecules lose their polarity and therefore become insoluble in water.
However, lipids are represented by classical triglycerides and include phospholipids and steroids. In the case of phospholipids, only two of the three glycerol atoms are replaced by carboxylic acid residues, and the third atom is used to bond to phosphoric acid residues (Ajiboye). Phospholipids acquire polarity in this way, so they are often regarded as a system of a hydrophilic head that interacts with water and a hydrophobic tail that rejects water molecules. Finally, steroids are the third type of lipid with a unique structural formula. All steroids have four carbon homocyclic, with hydrogen substituted for radicals and additional atoms (Figure 3). By their type, steroids are often referred to as alcohols that have no fatty acid residues, unlike other types of lipids.
It can be mistakenly thought that lipids are superfluous to the body because they are responsible for overweight and obesity. The connection between fat molecules and overweight is indeed traceable, but the natural function of lipids in the human body is much broader. The energy function of lipids is to release about 38-39 kJ of energy when one fat molecule (NA) breaks down. This is the highest number among the three “fats, proteins, and carbohydrates,” but it is carbohydrates that are traditionally used by the body for primary energy production because of their more significant amount. The storing function of fats is realized as an alternative to carbohydrates because the individual is protected from prolonged hunger. Lipids are stored in adipose tissue for survival under adverse conditions; fat accumulates as droplets in adipocyte cells. Interestingly, the number of adipocytes is not related to obesity because it is invariable; instead, these cells can increase in volume, which leads to overweight (Vishvanath and Gupta 4022).
As illustrated in Figure 2, phospholipids also have a structural function, forming the backbone of the semipermeable cell membrane. Steroids like cholesterol and testosterone have a regulatory function in the body, maintaining the body’s metabolic profile. Any changes in the balance of hormones and other steroids lead to dysfunction. However, lipids in the body are not limited to the functions listed above but are also responsible for heat regulation, mechanical and water-repellent protection, or the formation of impulse signals. Consequently, it is reasonable to conclude6 that lipids perform a large number of functions in the body and are therefore essential substances.
Relationship to Health
Strictly speaking, one cannot say that lipids have any connection with health since their existence in the body is an integral part of the existence of the organism in general. However, an imbalance of lipids and their dysfunction leads to health problems manifested in metabolic disorders. Excess lipids lead to overweight problems, resulting in exacerbation of chronic diseases and more complex to tolerate infectious diseases. Obesity also affects the cardiovascular system, including cardiomegaly and heart failure (MCS). An excess or deficiency of cholesterol in the diet leads, in turn, to a disturbed lipid profile or dyslipidemia.
This imbalance causes patients to suffer from atherosclerosis and strokes. In addition, fatty acid residues in lipids can be saturated or unsaturated, depending on the presence of multiple bonds between carbons. Saturated fats are found in meat and milk and are generally not harmful to health. However, their excess leads to higher levels of bad cholesterol, which affects the metabolic profile; this leads to disease (Bridges). It is a person’s responsibility to have regular blood tests for general analysis, including a lipid profile. Developing problems with no obvious symptoms can be detected by examining the body’s lipid balance. Any excesses or deficiencies indicate abnormalities, the detailed study of which helps improve quality of life in the long run.
Ajiboye, Tolu. “What Is a Lipid?” VeryWellHealth. 2021. Web.
Bridges, Meagan. “Facts about saturated fats.” Medline Plus, 2020. Web.
Madhu. “Difference Between Glycolipids and Phospholipids“. Difference Between. 2020. Web.
MCS. “Enlarged heart“. Mayo Clinic. 2020. Web.
NA. “Balancing Energy In and Energy Out“. Nutrition Australia. 2021. Web.
Vishvanath, Lavanya, and Rana K. Gupta. “Contribution of Adipogenesis to Healthy Adipose Tissue Expansion in Obesity.” The Journal of Clinical Investigation, vol. 129, no. 10, 2019, pp. 4022-4031.