Every skincare routine can benefit from the addition of an exfoliant. Of all skincare practises, it’s the one step guaranteed to provide instant results. Often touted as the key to glowing skin, exfoliation is easily integrated and quickly effective.
Using an exfoliant is also not an isolated benefit, the skin may instantly feel and appear smoother, however, this effect also helps prepare skin for penetration by serums and moisturisers, maximizing the benefits of a skincare routine.
There are many different methods of exfoliation and choosing the most appropriate depends on a person’s age, skin type, and skin concerns.
The benefits of exfoliation
For many, exfoliation is a process used to achieve smooth, silky skin; however, there are many more beneficial side effects. Similarly, to hair and nails, skin sits in a constant state of renewal. Skin cells are born, skin cells mature and finally skin cells desquamate (exfoliate). This process is normal, natural and healthy – scientists call it skin’s cell turnover rate. When skin behaves healthily, skin cell turnover occurs in the order of around 30 days1. Successful turnover allows for an even skin tone and a youthful, voluminous glow. When skin cell turnover slows, as it does naturally with age, skin can become dull, uneven looking and prone to congestion. Exfoliation can help increase a declining skin cell turnover rate also leading to;
- Prevention of spots, pimples, and acne
Congestion within skin often leads to the emergence of spots. When a person’s skin cell turnover rate slows, dead skin cells remain in place for longer. Their collection is most prominent in people with an oily to combination skin type as increased sebum production leads to added adhesion. Spots are provoked by a combination of 3 factors; dead skin cells collecting in sebum plugs providing nutrients for acne causing bacteria – p.acnes2. Exfoliation helps to prevent the collection of dead skin cells within sebum, therefore reducing outbreaks of spots.
- Helps to minimize the appearance of pores
Pores grow in size with age and this is a direct consequence of a reduced skin cell turnover rate3. There are two types of pore found within skin – oil pores also known as hair follicles and sweat pores. Sweat pores are nearly invisible to the naked eye, however, oil pores are much larger. Oil pores are technically called hair follicles, an oil pore houses a hair and a sebum gland. Sebum is excreted to moisturise and lubricate the hair it houses alongside the surrounding skin. Due to their size and contents, oil pores are prone to attracting dead skin cells. As skin cell turnover slows, dead skin cell collection increases and pores become increasingly visible. Exfoliation helps minimize the appearance of pores by increasing skin cell turnover.
- Increased penetration of serums and moisturisers
The top layers of skin are technically classified as being ‘dead’ – keratinocytes – skin cells with a nucleus, differentiate into corneocytes – skin cells without a nucleus4. Terminally differentiated corneocytes form a waterproof barrier keeping harmful bacteria and irritants out and hydration in. However, as skin cell turnover slows with age, this layer of corneocytes thickens. While moisturisers and serums can hydrate these layers, the skin’s active ingredients are unable to interact with dead skin cells. Therefore it’s important these ingredients reach deeper layers of skin. Exfoliation helps to thin defensive corneocytes to enable effective penetration of active ingredients.
- Helps reduce the appearance of fine lines and wrinkles
Creases within the skin are pronounced by the build-up of dead skin. A thick layer of corneocytes will visibly accentuate fine lines and wrinkles as skin becomes uneven and patchy. It’s also possible for unevenly shed dead skin cells to promote the formation of fine lines. Exfoliation rebalances skin cell turnover and helps to prevent the visible effects of premature ageing.
- Evens skin tone
A youthful skin tone is even, bright and dewy. An aged skin tone is dull, sallow and dehydrated. As skin cell turnover slows, skin tone becomes patchy and uneven creating a prematurely aged appearance. It is not just the slowing of skin cell turnover that is of importance but also how evenly dead skin cells are shed. Uneven accumulation can lead to an uneven skin tone – exfoliation helps brighten these areas. Due to this effect, exfoliation is also helpful in reducing the appearance of hyperpigmentation.
How to exfoliate
There are several forms of exfoliation, each offering different benefits to skin – some work instantly, others build with time. Some are great for sensitive skin, others are suited to an oily skin type. Best results are achieved when using an exfoliation technique tailored to an individual’s skin type.
Although there are many forms of exfoliation e.g. facial brushes, muslin cloths, Konjac sponges, each technique fits into one of two families;
Physical exfoliation techniques use manual action to gently tease away layers of dead skin cells. To use a physical exfoliant a gentle scrubbing action is required. Conversely, chemical exfoliation techniques use chemical action to dissolve away layers of dead skin cells. To use a chemical exfoliant a solution is wiped over the skin.
There are 9 common types of exfoliating products;
Facial scrubs use powders or microbeads to mildly buff away a layer of dead skin cells. Microbeads can be renewable i.e. made of jojoba wax or polluting i.e. made from plastic. Many facial scrubs contain powders made from broken nuts or seeds, although natural, these ingredients are not perfectly spherical and may, therefore, cause microtears – invisible to the naked eye trauma. Facial scrubs are not recommended for sensitive skin types.
Facial brushes are a recent and new exfoliating concept, they work in a similar way to facial scrubs, however instead of exfoliating powders, they use an exfoliating brush. Facial brushes are not recommended for sensitive skin types.
Konjac sponges are a natural form of sponge – instead of the traditional ocean sourced sponge, Konjac sponges are made from the Konjac plant – a potato plant native to Asia. Konjac sponges provide a gentle method of physical exfoliation, however, their porous nature can lead to the accumulation of dirt. Konjac sponges may not be washed, however, may be microwaved for sanitation.
Muslin cloths are an extremely natural method of exfoliation, using a finely-woven, breathable form of cotton to gently and mildly tease dead skin cells away from the stratum corneum. Muslin cloths can be used alone on dampened skin or in combination with a skin type-appropriate cleanser. As a physical method of exfoliation, the effect and sensitivity can be tailored to a person’s skin type. For particularly sensitive skin, a much lighter touch will tailor treatment, for normal skin types, a slightly longer treatment of skin may be appropriate. Muslin cloths such as the griffin+row Exfoliate natural exfoliant cloth can be washed weekly along with other cotton to remove dead skin build up and prevent bacterial contamination – this is a great benefit over other less easily cleanable methods of physical exfoliation. Muslin cloths such as the griffin+row Exfoliate natural exfoliant cloth can be used up to 100 times and are also bio-degradable.
Alpha-hydroxy acids (AHAs) are a type of chemical exfoliant suited for normal to dry skin types. Chemical exfoliants gradually break down the glue which holds dead skin cells together. The most commonly used AHA is glycolic acid. AHAs can be found in cleansers, toners and even in moisturisers.
Beta-hydroxy acids (BHAs) work similarly to AHAs, however, dissolve more easily within oils. This difference in chemistry means BHA containing skincare products are specifically suited for oily to combination skin types. The most commonly used BHA is salicylic acid.
Enzyme-based exfoliants are a chemical exfoliant with a similar mode of action to AHAs or BHAs. Enzymes such as bromelain or papain are considered milder than exfoliating acids, however, do require specific conditions e.g. pH to work effectively. Results can be variable.
Chemical peels are considered treatment products not designed for everyday use. They contain concentrated quantities of AHAs and BHAs which cause a very quick shedding of the stratum corneum. Chemical peels are not recommended for sensitive skin types.
Microdermabrasion is a salon based physical method of exfoliation. Microdermabrasion is also considered a treatment product not designed for everyday use. It uses a fine stream of powder, blown quickly towards skin to loosen and remove dead skin cells. Microdermabrasion is not recommended for sensitive skin types.
Is it possible to over-exfoliate?
The results of exfoliating regularly bring great benefits to skin, however, the very same benefits may be tipped the opposite way if overused. Exfoliating helps to remove dead skin cell build-up, however, skin requires a layer of dead skin cells to maintain its hydration and to defend from ever present irritants, allergens and sensitizers e.g. pollen, fragrance, and dyes found in clothes. Overuse of an exfoliating product thins the stratum corneum severely resulting in uncomfortable symptoms.
What are the signs of over-exfoliation?
There are many symptoms of over exfoliation, all resulting from an impaired barrier function. If skin has been over exfoliated it’s likely to show symptoms of;
Sensitivity / heightened sensitivity
Dry, flaky areas of skin – although an already dry and flaky skin type can be improved with regular exfoliation, a skin type that has been over-exfoliated will begin to rear similar symptoms. An important function of the skin barrier is to retain hydration, when an individual’s skin barrier becomes over thinned, it becomes ineffective and therefore dry and flaky.
Shiny skin – the easiest to spot warning sign of over-exfoliation. Shiny skin appears when light has no texture to dissipate into, instead directly bounding off from the skin. The skin should naturally have a degree of texture.
The Hayflick limit – Is exfoliating pro-ageing?
All differentiated cells have the ability to replicate themselves, however, this ability is not eternal – a phenomenon referred to as the Hayflick limit. This, therefore, raises the question – will exfoliation speed up skin’s ageing process? If skin cells live for only a specified period of time, exfoliation would speed their death.
The Hayflick limit defines a cell’s lifetime as around 50 replications, after which it reaches a state of senescence. Differentiated cells have a strand of DNA with a cap at each end – this cap is technically referred to as a telomere. On each cell, replication telomeres shorten until they shorten to such an extent that replication becomes impossible5. This is the definition of cell senescence. Stress accelerates the shortening of telomeres whereas antioxidants decelerate it6.
The deepest layer of the skin’s epidermis – the stratum basale, contains undifferentiated keratinocytes i.e. stem cells. An undifferentiated cell has not yet decided or programmed its final use, whereas a differentiated cell performs a specific function.
The Hayflick limit only applies to differentiated cells. Therefore exfoliating will not cause premature ageing. If only differentiated skin cells existed, the skin would not last a lifetime7.
Sources and References:
- Alberts B, Johnson A, Lewis J, et al. Molecular Biology of the Cell. 4th edition. New York: Garland Science; 2002. Epidermis and Its Renewal by Stem Cells. Available from: https://www.ncbi.nlm.nih.gov/books/NBK26865/
- Pathological mechanisms of acne with special emphasis on Propionibacterium acnes and related therapy. Uta Jappe Acta Derm Venereol. 2003; 83(4): 241–248.
- Age-related changes in sebaceous gland activity. P. E. Pochi, J. S. Strauss, D. T. Downing J Invest Dermatol. 1979 Jul; 73(1): 108–111.
- Isolation, cultivation, and differentiation of normal human epidermal keratinocytes in serum-free medium. Zellmer S, Reissig D. Methods Mol Biol. 2002;188:179-84.
- R C Allsopp, H Vaziri, C Patterson, S Goldstein, E V Younglai, A B Futcher, C W Greider, and C B Harley, Telomere length predicts replicative capacity of human fibroblasts, PNAS 1992 89 (21) 10114-10118
- Oxidative stress shortens telomeres. von Zglinicki T. Trends Biochem Sci. 2002 Jul;27(7):339-44.
- Skin stem cells: rising to the surface. Fuchs E. J Cell Biol. 2008 Jan 28;180(2):273-84. doi: 10.1083/jcb.200708185. Epub 2008 Jan 21.