In recent years, exfoliating has gained popularity, and it is worth delving into the scientific basis of this practice, unraveling the advantages of using exfoliators, and the various exfoliating agents.
What is Exfoliation?
Exfoliation is the process of removing dead skin cells from the surface of the skin, revealing a smoother and brighter complexion. Our skin naturally sheds dead skin cells, but the process slows down as we age. This can lead to a build-up of dead skin cells, resulting in dull and rough-looking skin. Exfoliating can help to speed up the natural shedding process and remove dead skin cells, allowing the newer and healthier skin cells to come to the surface [1].
How Does it Work?
The process of natural skin exfoliation begins in the basal layer of the epidermis where new skin cells (keratinocytes) are generated. These newly formed cells gradually move towards the surface of the skin, maturing and differentiating into specialized cells as they migrate upwards through the epidermal layers. As they reach the uppermost layer of the epidermis (stratum corneum), the cells become flattened, lose water, and are filled with hardened proteins called keratin [1].
The skin cells are held together by a glue-like substance that holds dead skin cells together, called desmosomes, which gradually weaken as the cells move upwards towards the skin's surface. The weakening of the desmosome attachments is accelerated by enzymes that break down the bonds between the cells, allowing them to slough off naturally. This process of natural exfoliation is known as desquamation [1].
The duration of the entire process from the formation of new skin cells in the basal layer to their shedding from the skin's surface can take up to four weeks. However, factors like aging, hormonal changes, and environmental stressors can slow down the skin's natural exfoliation process, leading to a build-up of dead skin cells that can clog pores and dull the complexion. Younger skin is typically more efficient at exfoliating naturally than aged skin [1].
While the skin does exfoliate naturally, sometimes it may not be enough to remove all the dead skin cells. The use of physical or chemical exfoliants can help to accelerate the skin's natural exfoliation process, removing dead skin cells and revealing smoother, brighter skin. This can help to improve the texture and tone of the skin, minimize the appearance of fine lines and wrinkles, and prevent breakouts by keeping pores clear [1].
Physical Exfoliants
Physical exfoliants use mechanical abrasion to remove the top layer of dead skin cells from the skin's surface, revealing the underneath fresher, more and more youthful-looking skin. The abrasive particles in the exfoliating product create friction against the skin, loosening and removing the dead skin cells and causing controlled damage to the upper layer of the skin. This process triggers a wound-healing response that includes an increase in collagen production. Collagen is a protein that gives the skin its strength, elasticity, and firmness and is produced by specialized cells called fibroblasts in the dermis layer of the skin. When the skin is mechanically stimulated through exfoliation, it signals the fibroblasts to produce more collagen to repair the damage, resulting in improved skin texture, firmness, and overall health [2].
In addition to promoting collagen production, physical exfoliation also helps to improve blood circulation in the skin. The friction and pressure created by the exfoliating tool increase blood flow to the area, delivering more oxygen and nutrients to the skin cells, which can enhance collagen production and promote cell regeneration [2].
However, it's important to use physical exfoliants carefully as over-exfoliating with harsh or abrasive products can lead to skin irritation, inflammation, and even micro-tears in the skin, which can compromise the skin's natural barrier function [4]. The degree of exfoliation depends on the intensity of the scrubbing and the size of the exfoliating particles, with finer-grain scrubs providing gentler exfoliation and coarser scrubs offering a more aggressive exfoliation.
Microdermabrasion and hydra dermabrasion
Microdermabrasion exfoliates the skin by combining materials such as crystals or diamond flakes with machine-based suction. This treatment causes skin alterations such as re-arrangement of melanosomes, flattening of rete ridges, increased collagen fiber density, and vascular ectasia. Furthermore, it increases the upregulation of wound healing factors and matrix metalloproteinases in the dermis. Microdermabrasion is a simple, painless, and non-invasive process for skin renewal. The most secure method is to utilize corundum or aluminium oxide crystals, which are non-allergenic and antibacterial [5].
Another procedure related to microdermabrasion is hydra dermabrasion, which uses a high-speed mix of oxygen and aqueous solution to cleanse and moisturize the skin. This approach is suitable for a wide range of skin types, including darker, aging, sensitive, oily, and dry skin. It causes enhanced epidermis and papillary dermal thickness, better dermal tissue flexibility, collagen hyalinization, increased fibroblast density, and a decrease in fine lines, pore size, and hyperpigmentation. Overall, hydra dermabrasion improves skin quality significantly [5].
Chemical exfoliants
Chemical exfoliators utilize chemical compounds such as alpha-hydroxy acids (AHAs) and beta-hydroxy acids (BHAs) to dissolve dead skin cells. They offer more targeted and controlled exfoliation, making them suitable for various skin concerns.
Alpha-hydroxy acids (AHAs)
AHAs, like glycolic acid, mandelic acid, citric acid, and lactic acid are water-soluble acids that break down the bonds between cells (desmosomes) allowing them to be easily removed from the skin's surface, leading to gentle exfoliation. This helps to reveal smoother, brighter skin and can improve the appearance of fine lines, hyperpigmentation, and acne scars. When applied to the skin, AHAs also lower the pH level, making the skin slightly more acidic. This can help to improve skin barrier function. and helps to prevent water loss from the skin and maintain skin hydration levels [4]. AHAs may also have an impact on the skin's microbiota [4]. Studies have shown that AHAs can help to reduce the number of acne-causing bacteria on the skin and may promote a healthier balance of microorganisms [3].
In addition to exfoliation, AHAs also can aid in increasing skin hydration by attracting water molecules to the skin's surface. This is due to their hydrophilic (water-loving) nature. AHAs help to improve skin hydration by increasing the water content in the outermost layer of the skin (stratum corneum) leading to smoother and more supple skin. Additionally, AHAs can also stimulate the production of natural moisturizing factors (NMFs) in the skin, such as hyaluronic acid and urea, which further enhance skin hydration [4].
Beta-hydroxy acids (BHAs)
BHAs such as salicylic acid are oil-soluble and can penetrate the skin's lipid barrier and dissolve the sebum that can clog the pores. It also has anti-inflammatory and anti-bacterial properties. This makes it an effective treatment for acne, blackheads, and other forms of congestion. In addition to its exfoliating properties, salicylic acid can also stimulate collagen production in the skin [6].
AHAs and BHAs can be used by various skin types, but their suitability may vary depending on the individual's skin concerns and sensitivity. Such as AHAs are generally recommended for people with dry, sun-damaged, or aging skin as they help to exfoliate the surface layer of dead skin cells and improve the appearance of fine lines, wrinkles, and uneven skin tone. They can also help to improve skin texture and hydration levels [4]. BHAs, on the other hand, are recommended for people with oily, acne-prone, or combination skin as they penetrate deep into the pores to dissolve excess sebum and unclog pores. They also have anti-inflammatory and antibacterial properties that can help to reduce inflammation and prevent breakouts [6].
However, it is important to note that AHAs and BHAs can be irritating to some individuals, especially those with sensitive skin. It is recommended to patch test a product containing AHAs or BHAs and to start with a low concentration and frequency of use to minimize the risk of irritation. Consulting with a dermatologist or skincare professional can also help determine which type and concentration of AHA or BHA may be best suited for a particular skin type and concern.
Enzyme exfoliation
Enzymes used in skincare can be synthetic or derived from natural sources. They have the ability to dissolve dead skin cells and break down keratin, promoting the cell renewal process. Plant enzymes, such as papain from papaya, bromelain from pineapple, and enzymes from pumpkin, are proteolytic enzymes that stimulate exfoliation by breaking down the bonds between skin cells. These enzymes are often used as an alternative to acid peels, making them suitable for individuals with sensitive skin. Recent studies have explored the use of protease enzymes derived from the microorganism Bacillus subtilis as keratinolytic agents when applied topically. [5].
Enzymatic peels, also known as enzymocosmetics, are cosmetic products containing proteolytic enzymes that hydrolyze the proteins in the outer layer of the skin. They promote natural exfoliation, accelerate skin regeneration, and enhance the penetration of active ingredients in other skincare products. Enzymatic peels are commonly used for concerns such as pigmentation, acne spots, oily skin, and rough skin. They are generally considered more comfortable and safer than chemical peels, particularly for sensitive skin [5].
In summary, exfoliation is a science-backed skincare process that offers numerous advantages and can be tailored to individual preferences using a range of exfoliating products. To ensure effective and safe exfoliation, it is essential to consider factors such as skin type, sensitivity, and desired exfoliation intensity. By understanding specific skin needs and concerns, the most suitable exfoliator can be selected and incorporated into a skincare routine to maximize its benefits and minimize the risk of over-exfoliation or irritation.
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References:
Kandasamy, R., & Packianathan, N. (2011). Skin Care with Herbal Exfoliants Targeted delivery of metformin in the treatment of liver cancer View project Cellular imaging and folate receptor targeting delivery View project Functional Plant Science and Biotechnology Skin Care with Herbal Exfoliants. https://www.researchgate.net/publication/224892687
Anselem. (2023). Exfoliation 101: Benefits Of Exfoliating The Skin & Why It's A Must Do In Every Skincare Routine - BeautySparkReview. BeautySparkReview. https://www.beautysparkreview.com/benefits-of-exfoliating-the-skin/#:~:text=Exfoliation%20Increases%20cell%20turnover%20by%20stripping%20off%20dead,which%20in%20turn%20helps%20keep%20the%20skin%20healthy.
Ye, D., Xue, H., Huang, S., He, S., Li, Y., Liu, J., Yang, X., & Zeng, W. (2022). A prospective, randomized, split‐face study of concomitant administration of low‐dose oral isotretinoin with 30% salicylic acid chemical peeling for the treatment of acne vulgaris in the Asian population. International Journal of Dermatology, 61(6), 698–706. https://doi.org/10.1111/ijd.16127
Tang, S., & Yang, J. (2018). Dual Effects of Alpha-Hydroxy Acids on the Skin. Molecules, 23(4), 863. https://doi.org/10.3390/molecules23040863
Behalpade, S., & Gajbhiye, S. (2022). Skin Care with exfoliation process. International Journal of Current Science, 12(ISSN: 2250-1770). https://www.ijcspub.org/papers/IJCSP22B1150.pdf
Allnaturalantiagingskincareaprioribeauty, B. (2011, September 4). Alpha-Hydroxy & Beta-Hydroxy Acids. Allnaturalantiagingskincareaprioribeauty.
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Keywords: Exfoliators, exfoliating, dead skin, collagen, physical exfoliants, chemical exfoliants, Alpha-hydroxy acids (AHAs), Beta-hydroxy acids (BHAs), skincare