What is sebum and what is its role in maintaining skin health?
Posted by Ivatherm
Sebum is an oily substance produced by the sebaceous glands, which are found all over the body.
Sebum is composed of lipids, which help hydrate the skin and protect it against harmful pathogens, such as bacteria. Therefore, sebum has antibacterial properties and represents the body's first line of defense against infections.
Although sebum is important for skin health, too much or too little oil can cause acne, oily skin, pruritus (intense itching), and irritation. In this article, we will explain what sebum is, its functions, what excessive or insufficient production means, and how we can maintain its optimal balance through a correct skincare routine.
Table of Contents
What is sebum?
Sebum is a natural, oily substance produced by the sebaceous glands, which are located in the middle layer of the skin (dermis), near the hair follicles. These glands are found all over the body, but are more concentrated in certain areas, such as the face, scalp, and upper back.
There are two types of sebaceous glands:
sebaceous glands attached to hair follicles;
sebaceous glands not attached to hair follicles.
Most sebaceous glands are connected to hair follicles. Some sebaceous glands work with sweat glands and open to the skin's surface instead of opening to hair follicles. Both types perform the same function: to create and release sebum.
Sebum is composed of several types of fat molecules (lipids), specifically triglycerides (30% to 50%), fatty acids (15-30%), wax esters (26%-30%), squalene (12-20%), cholesterol esters (3% to 6%), and cholesterol (1.5% to 2.5%).
These lipids work together to hydrate the skin and defend the body. For example, lipids seal moisture into the skin, leaving the skin hydrated and providing protection against ultraviolet radiation. Sebum also transports fat-soluble antioxidants, such as vitamin E, to the skin's surface. This action can help prevent oxidative damage to the skin. Many components of sebum have anti-inflammatory properties.
In addition to these components, a bacterium called Cutibacterium acnes (formerly known as Propionibacterium acnes) is naturally found in sebum. As the name suggests, this is the bacterium that causes acne.
Sebum is odorless. However, when broken down by bacteria, along with sweat and keratin (the protein that forms the structure of skin, hair, and nails), it acquires the distinctive body odor. This is why children tend not to have a specific smell until puberty, when there is a significant increase in sebum production.
What is the role of sebum?
Sebum is a necessary component for healthy skin. It hydrates and protects the surface of the entire body.
Skin hydration
One of the main functions of sebum is to hydrate the skin. It forms a thin, protective layer that helps maintain moisture within the skin, which promotes hydration. However, it is important that the levels of secreted lipids are correctly balanced to prevent skin irritation.
Skin protection
At the same time, sebum acts as a natural barrier, protecting the skin from environmental aggressors, such as pollutants, bacteria, and other potentially harmful substances. It creates a slightly acidic environment on the skin's surface. Sebum has a pH between 4.5 and 6.0. As a result, it helps prevent harmful pathogens, such as bacteria and viruses, from penetrating the skin by supporting the skin's natural defense mechanisms and a healthy microbiome.
Antioxidant transport
Last but not least, sebum transports fat-soluble antioxidants to the skin's surface. Antioxidants are natural compounds that protect the body against free radicals, which can cause oxidative stress, responsible for premature skin aging.
Sebum production – from excess to deficiency
Mechanism of sebum production
The face, scalp, and chest have the highest concentrations of sebaceous glands, with each skin area potentially having up to 900 glands per square centimeter.
Sebaceous glands produce sebum through holocrine secretion, a process of programmed cell death. Specialized cells, called sebocytes, dissolve and release sebum into the sebaceous glands.
Sebum travels through the follicular canal, which connects the sebaceous gland to the hair follicle. The growing hair pushes the sebum to the skin's surface.
Sebum production fluctuates depending on hormonal changes. Sex hormones traditionally considered male (androgens), especially testosterone, play an important role in regulating the activity of sebaceous glands.
Androgen hormones are produced by the adrenal glands and ovaries or testes. These glands are, in turn, regulated by the pituitary gland in the brain. The pituitary gland is responsible for the entire endocrine (hormonal) system of the body. The more active the androgen hormones are, the more sebum the body can produce.
Evolution of sebum production throughout life
Sebum production peaks shortly after birth and decreases in the first week of life. During puberty, testosterone floods the body, triggering another peak in sebum production. Testosterone and sebum levels naturally decrease with age.
All babies are born with sebaceous glands over most of their body, except for the palms, soles, and lower lip. The glands produce significant amounts of sebum immediately after birth. This happens because newborns have high testosterone levels.
In childhood, hormone levels balance out, and the sebaceous glands become less active. Children produce very little sebum between 2 and 6 years of age. As puberty approaches, androgen hormones again flood the body, and the glands pump out constant amounts of sebum. Sebum production begins to decrease from the age of 20 and reaches normal levels during adulthood. After the age of 70, the body's sebum production gradually slows down.
The face, scalp, upper neck, and chest have the most sebaceous glands, so when there is an increase in sebum production, these areas are prone to acne breakouts or oily skin.
Excess sebum production
Sebum production is related to age-related hormonal fluctuations, the consumption of certain medications, or lifestyle.
Excess sebum production can lead to oily skin. In people with oily skin, the appearance of pores is larger, and their skin is shiny.
Also due to excess sebum production, acne breakouts can occur. These arise when hair follicles become blocked, and oil accumulates under the skin. Skin cells, sebum, and hair can collect in a "plug" which becomes infected with bacteria and results in inflammation. When the clogged follicle is near the surface of the skin, it swells outward, creating a whitehead. On the other hand, the clogged follicle can be open on the skin, creating a blackhead.
Oily skin can be kept under control through an effective skincare routine. Products containing beta-hydroxy acids (BHAs), such as salicylic acid, and alpha-hydroxy acids (AHAs), such as glycolic acid, are effective in treating oily skin. In contrast, it is good to avoid oil- or alcohol-based cleansers, as these can irritate the skin, triggering greater sebum production.
When there are hormonal imbalances, sebum production can be excessive, which can cause a number of skin conditions and problems:
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Insufficient sebum production
Insufficient sebum production can also cause problems. Several factors can suppress sebum production:
exposure to allergens or harsh chemicals;
certain contraceptives;
malnutrition;
pituitary gland disorders.
People with hypoactive sebaceous glands or too little sebum may have dry, flaky, and itchy skin. These symptoms can worsen if a person uses skincare products containing harsh substances.
Moisturizers containing ceramides or humectants can help relieve dry skin. Therefore, in the daily skincare routine, cosmetic products containing hyaluronic acid, alpha-hydroxy acids, glycerin, and jojoba oil are recommended.
Sebum production can be severely affected by eating disorders, severe fasting, and malnutrition.
The most common problem associated with insufficient sebum is dry, red, flaky, and itchy skin, which can be exacerbated by harsh soaps or hot showers.
Balanced sebum production
The skincare routine plays an essential role in maintaining a balance of sebum production.
Regular skin cleansing with a gentle, pH-balanced product can help remove excess sebum and impurities, without stripping the skin of its natural oils.
Hydration is important to maintain a healthy sebum balance. Using a lightweight, non-comedogenic moisturizer provides the skin with necessary hydration without clogging pores.
Avoiding excessive washing to combat oily skin. This action can, in fact, stimulate sebum production. A gentle cleansing routine and avoiding harsh exfoliants or products that strip the skin of its natural oils are recommended.
A healthy diet rich in essential fatty acids, vitamins, and antioxidants, can support overall skin health. Additionally, managing stress levels and getting adequate sleep can also contribute to balanced sebum production.
Excessive sebum production can lead to oily skin or acne, while insufficient production of this natural oil can lead to dry skin, itching, or flaking. A healthy lifestyle and a correct skincare routine help rebalance sebum levels, so that the skin is protected and well-hydrated, at any age.
Conținutul IvaStories este creat de echipa Ivatherm, brand romanesc de dermatocosmetice fondat de Dr. Rucsandra Hurezeanu. Produsele Ivatherm sunt formulate cu Apă Termală Herculane și sunt testate dermatologic, recomandate de medici specialiști.
What is sebum and what is its role in maintaining skin health?
Sebum is an oily substance produced by the sebaceous glands, which are found all over the body.
Sebum is composed of lipids, which help hydrate the skin and protect it against harmful pathogens, such as bacteria. Therefore, sebum has antibacterial properties and represents the body's first line of defense against infections.
Although sebum is important for skin health, too much or too little oil can cause acne, oily skin, pruritus (intense itching), and irritation. In this article, we will explain what sebum is, its functions, what excessive or insufficient production means, and how we can maintain its optimal balance through a correct skincare routine.
Table of Contents
What is sebum?
Sebum is a natural, oily substance produced by the sebaceous glands, which are located in the middle layer of the skin (dermis), near the hair follicles. These glands are found all over the body, but are more concentrated in certain areas, such as the face, scalp, and upper back.
There are two types of sebaceous glands:
Most sebaceous glands are connected to hair follicles. Some sebaceous glands work with sweat glands and open to the skin's surface instead of opening to hair follicles. Both types perform the same function: to create and release sebum.
Sebum is composed of several types of fat molecules (lipids), specifically triglycerides (30% to 50%), fatty acids (15-30%), wax esters (26%-30%), squalene (12-20%), cholesterol esters (3% to 6%), and cholesterol (1.5% to 2.5%).
These lipids work together to hydrate the skin and defend the body. For example, lipids seal moisture into the skin, leaving the skin hydrated and providing protection against ultraviolet radiation. Sebum also transports fat-soluble antioxidants, such as vitamin E, to the skin's surface. This action can help prevent oxidative damage to the skin. Many components of sebum have anti-inflammatory properties.
In addition to these components, a bacterium called Cutibacterium acnes (formerly known as Propionibacterium acnes) is naturally found in sebum. As the name suggests, this is the bacterium that causes acne.
Sebum is odorless. However, when broken down by bacteria, along with sweat and keratin (the protein that forms the structure of skin, hair, and nails), it acquires the distinctive body odor. This is why children tend not to have a specific smell until puberty, when there is a significant increase in sebum production.
What is the role of sebum?
Sebum is a necessary component for healthy skin. It hydrates and protects the surface of the entire body.
Skin hydration
One of the main functions of sebum is to hydrate the skin. It forms a thin, protective layer that helps maintain moisture within the skin, which promotes hydration. However, it is important that the levels of secreted lipids are correctly balanced to prevent skin irritation.
Skin protection
At the same time, sebum acts as a natural barrier, protecting the skin from environmental aggressors, such as pollutants, bacteria, and other potentially harmful substances. It creates a slightly acidic environment on the skin's surface. Sebum has a pH between 4.5 and 6.0. As a result, it helps prevent harmful pathogens, such as bacteria and viruses, from penetrating the skin by supporting the skin's natural defense mechanisms and a healthy microbiome.
Antioxidant transport
Last but not least, sebum transports fat-soluble antioxidants to the skin's surface. Antioxidants are natural compounds that protect the body against free radicals, which can cause oxidative stress, responsible for premature skin aging.
Sebum production – from excess to deficiency
Mechanism of sebum production
The face, scalp, and chest have the highest concentrations of sebaceous glands, with each skin area potentially having up to 900 glands per square centimeter.
Sebaceous glands produce sebum through holocrine secretion, a process of programmed cell death. Specialized cells, called sebocytes, dissolve and release sebum into the sebaceous glands.
Sebum travels through the follicular canal, which connects the sebaceous gland to the hair follicle. The growing hair pushes the sebum to the skin's surface.
Sebum production fluctuates depending on hormonal changes. Sex hormones traditionally considered male (androgens), especially testosterone, play an important role in regulating the activity of sebaceous glands.
Androgen hormones are produced by the adrenal glands and ovaries or testes. These glands are, in turn, regulated by the pituitary gland in the brain. The pituitary gland is responsible for the entire endocrine (hormonal) system of the body. The more active the androgen hormones are, the more sebum the body can produce.
Evolution of sebum production throughout life
Sebum production peaks shortly after birth and decreases in the first week of life. During puberty, testosterone floods the body, triggering another peak in sebum production. Testosterone and sebum levels naturally decrease with age.
All babies are born with sebaceous glands over most of their body, except for the palms, soles, and lower lip. The glands produce significant amounts of sebum immediately after birth. This happens because newborns have high testosterone levels.
In childhood, hormone levels balance out, and the sebaceous glands become less active. Children produce very little sebum between 2 and 6 years of age. As puberty approaches, androgen hormones again flood the body, and the glands pump out constant amounts of sebum. Sebum production begins to decrease from the age of 20 and reaches normal levels during adulthood. After the age of 70, the body's sebum production gradually slows down.
The face, scalp, upper neck, and chest have the most sebaceous glands, so when there is an increase in sebum production, these areas are prone to acne breakouts or oily skin.
Excess sebum production
Sebum production is related to age-related hormonal fluctuations, the consumption of certain medications, or lifestyle.
Excess sebum production can lead to oily skin. In people with oily skin, the appearance of pores is larger, and their skin is shiny.
Also due to excess sebum production, acne breakouts can occur. These arise when hair follicles become blocked, and oil accumulates under the skin. Skin cells, sebum, and hair can collect in a "plug" which becomes infected with bacteria and results in inflammation. When the clogged follicle is near the surface of the skin, it swells outward, creating a whitehead. On the other hand, the clogged follicle can be open on the skin, creating a blackhead.
Oily skin can be kept under control through an effective skincare routine. Products containing beta-hydroxy acids (BHAs), such as salicylic acid, and alpha-hydroxy acids (AHAs), such as glycolic acid, are effective in treating oily skin. In contrast, it is good to avoid oil- or alcohol-based cleansers, as these can irritate the skin, triggering greater sebum production.
When there are hormonal imbalances, sebum production can be excessive, which can cause a number of skin conditions and problems:
Insufficient sebum production
Insufficient sebum production can also cause problems. Several factors can suppress sebum production:
People with hypoactive sebaceous glands or too little sebum may have dry, flaky, and itchy skin. These symptoms can worsen if a person uses skincare products containing harsh substances.
Moisturizers containing ceramides or humectants can help relieve dry skin. Therefore, in the daily skincare routine, cosmetic products containing hyaluronic acid, alpha-hydroxy acids, glycerin, and jojoba oil are recommended.
Sebum production can be severely affected by eating disorders, severe fasting, and malnutrition.
The most common problem associated with insufficient sebum is dry, red, flaky, and itchy skin, which can be exacerbated by harsh soaps or hot showers.
Balanced sebum production
The skincare routine plays an essential role in maintaining a balance of sebum production.
Excessive sebum production can lead to oily skin or acne, while insufficient production of this natural oil can lead to dry skin, itching, or flaking. A healthy lifestyle and a correct skincare routine help rebalance sebum levels, so that the skin is protected and well-hydrated, at any age.
Resources:
https://www.medicalnewstoday.com/articles/sebum#summary
https://www.verywellhealth.com/what-is-sebum-1069375
https://www.healthline.com/health/beauty-skin-care/sebum#hormones
https://my.clevelandclinic.org/health/body/24538-sebaceous-glands
https://skinkraft.com/blogs/articles/sebaceous-glands-sebum
Echipa Ivatherm
Conținutul IvaStories este creat de echipa Ivatherm, brand romanesc de dermatocosmetice fondat de Dr. Rucsandra Hurezeanu. Produsele Ivatherm sunt formulate cu Apă Termală Herculane și sunt testate dermatologic, recomandate de medici specialiști.