Body processes

Fat Film – Function, Task & Diseases

Greasy film

The skin ‘s sebum is a chemical, slightly acidic, fat-water layer on the skin’s surface composed of the secretions of the sebaceous and sweat glands . This layer acts like a chemical barrier to pathogens. Skin that is too dry can eliminate this barrier function.

What is the fat film?

Human skin has a natural film of water and fat. This film comes from the skin glands, which can be divided into sebaceous and sweat glands. They end in exit ducts and contractile glands on the skin surface. Both sweat, sebum and breakdown products of the cornification processes are released from these canals. The secretions of the skin glands form the fatty film on the skin.

Since the beginning of the 20th century, the natural water-fat film has sometimes been referred to as the skin’s protective acid mantle . Already in previous centuries physicians determined that the entire skin is covered by such a layer of acid. In the 20th century, the physician Alfred Marchionini drew new conclusions about the function of this acidic film.

The weakly acidic pH value of human skin is between four and seven and, according to Marchionini, is primarily intended to protect the epidermis from pathogens by fighting off bacteria . However, since some bacteria can also thrive in a slightly acidic environment, this theory is now the subject of criticism. According to the current state of science, the antibacterial function of the water-fat film is not due to the acid content, but to the peptides and lipids contained in the fat film .

function & task

Several gland secretions are contained in the skin’s natural fatty film. The secretions of the sebaceous glands and the sweat glands meet in the fatty film and differ enormously in their ingredients. In addition to uric acid and water, the ultimate fat film mainly contains electrolytes , urea , peptides and fatty acids . 

The most important electrolytes in the human body include salts such as sodium , potassium , calcium or magnesium , which dissociate in the electric field. Uric acid is found primarily in human sweat and acts as an antioxidant. Urea, in turn, is a detoxification substance that contains some level of toxic ammonia . Peptides are bacteria-resistant molecules made from amino acids . The fatty acids in turn come from the sebaceous glands. Important acids in this context are above all the omega-3 fatty acids , which are crucial components for the skin’s moisture balance.

These components are not only excreted to the outside, but also accumulate in the horny layer of the skin. Above all, numerous fats are stored between the individual horny cells, which connect the cells like mortar. This makes the skin water-repellent and gives it a smooth surface. The skin flora is ideally adapted to the chemical biotope from the substances mentioned. This means that the protective germs in your own skin can easily withstand the chemical environment of the greasy film.

However, the biotope made up of the specific compounds of the components mentioned often acts as a chemical barrier on other microorganisms. The secretions from the skin glands protect the human skin and mucous membranes from the growth of foreign microorganisms. In addition, the greasy film prevents the skin from drying out or cracking. The general resilience and durability of the skin layers therefore depends not least on the water-fat film of the skin.

Diseases & Ailments

A malfunction of the skin glands can change the composition of the natural fat film on the skin’s surface and become noticeable in various symptoms. Extremely dry skin, for example, can indicate pathological symptoms in connection with the fatty layer. There are many possible causes of dry skin and thus disrupted oil film production. In addition to metabolic disorders such as diabetes or thyroid dysfunction , hormonal disorders can also be considered as causes. 

Under certain circumstances, however, the patient drinks too little or follows harmful hygiene rituals. Skin care with alkaline products, for example, can cause the skin to dry out, since alkaline substances flush out the lipids from the horny layers. Even eating disorders , alcoholism and other addictions can alter the composition of the skin’s natural oily film, causing it to dry out.

However, the horny layer in particular still dries out most frequently due to excessive contact with water, cleaning solutions or solvents. Although the greasy film can regenerate to a certain extent, certain hygiene habits or everyday handling of solvents all too often overwhelm the ability to regenerate. In the worst case, the barrier function of the skin can weaken. Germs and bacteria now have an easy time colonizing the skin and chemical pollutants are only kept out to a limited extent. Eczema or other skin diseases often develop as part of this .

If such complaints are recognized early enough and the living situation is changed for the sake of the natural fat film, the skin can in most cases regenerate completely. On the other hand, if the bad habits are continued, dry skin can develop into an even bigger health problem. In extreme cases, for example, the horny layer of the skin is attacked. Without the natural fat film, there are hardly any fatty acids between the horny cells and the cells no longer hold together ideally. The skin becomes cracked and ailing as a result.

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.