Every day, your skin acts as a barrier between your body and various potential external dangers. From unseen microbes to harsh chemicals, pollutants, and ultraviolet (UV) light, it’s the body’s first line of defense – tirelessly working to shield you from harm. Amidst this ongoing battle, your skin performs a silent yet vital task: cellular repair. It’s the foundation of your skin’s biological aging clock.

Beneath its surface, skin is a bustling hub of activity, constantly engaged in repairing damage to uphold its structure, function, and overall appearance. However, despite its best efforts, not every repair is successful, and some changes, like those caused by internal aging signals or external oxidative damage, are inevitable.1 

The good news is, you can take steps to support your skin. By understanding repair mechanisms and implementing practices that promote skin health, you’re a strong ally in helping skin remain resilient.

Skin damage: Natural aging versus premature aging

The appearance of your skin is often the first hint the aging process is taking place within your body. Aging skin is categorized in two ways: intrinsic and extrinsic.2

Intrinsic skin aging is natural aging caused by simply getting older. For example, the skin’s dermis layer experiences a 1-percent reduction in collagen each year due to less collagen synthesis and increased damage to existing collagen, resulting in reduced structural support in the skin.2

A driving factor behind intrinsic skin aging is cellular senescence, a process in aging cells that leads to a decreased ability for cells to renew. Senescent cells – also called zombie cells – are damaged cells that no longer function but are not removed from your body. Senescent cells in the skin produce negative signals that cause surrounding healthy cells to malfunction. Aging can also cause mitochondrial dysfunction, which can lead to increased free radical production. Free radicals are associated with oxidative damage that exacerbates aging. Changes related to intrinsic skin aging include thinning, dryness, fine wrinkles, easy bruising, and sagging.2

Extrinsic skin aging stems from outside threats, including sun exposure (UV light), pollution, cigarette smoking, and poor nutrition. UV light accelerates aging by damaging the skin’s protective abilities, leading to DNA damage, suppression of DNA synthesis, cell death, and skin redness.2 

Long-term UV damage also causes photoaging, which triggers premature skin aging and increases the risk of skin cancer. Signs of extrinsic skin aging include coarser wrinkles, severe loss of skin elasticity, and abnormal pigmentation or skin color.2

How skin fights back

The skin is comprised of three layers: the epidermis (the most superficial layer), the dermis, and the hypodermis (the deepest layer). Cellular repair mechanisms that occur in these layers are essential for maintaining skin health, integrity, and youthful appearance.3

1. Stimulating collagen and elastin for strength and elasticity. Collagen and elastin are two major groups of proteins located in the extracellular matrix (ECM) of the dermis. This matrix is an extensive network of proteins and other molecules that support and give structure to cells and tissue.4,5 

Fibroblasts secrete collagen and elastin when stimulated by growth factors – the substances that regulate cell division and cell survival. Collagen plays a significant role in skin's structural organization, integrity, and strength. Together with elastin, it also gives the skin its elasticity and resiliency.4,6 

2. Repairing DNA. The skin is constantly exposed to environmental stressors, such as UV radiation and pollutants that can cause DNA damage. Accumulated DNA damage contributes to aging, manifesting as wrinkles, dryness and, in extreme cases, skin cancer.7,8 

DNA repair mechanisms help offset this damage. Nucleotide excision repair (NER) is one of the primary DNA repair mechanisms in skin cells that responds to UV radiation damage. NER identifies and removes damaged DNA segments, then synthesizes new DNA to replace the damaged sections.7-9 

3. Making room for new skin. The epidermis is in a perpetual state of turning over cells, fully renewing the body’s supply of skin cells every four weeks to maintain consistent tissue thickness.10-12 

Scientists call this desquamation – in layperson’s terms, it’s the cell repair process that sheds dead, dull flakes in clumps and allows newly formed cells to make their way to the skin’s surface, giving it a smoother appearance.10-12 

As you age, this process takes longer – up to eight weeks in older adults – which explains why skin can look duller as you age compared to the skin of your youth.12

4. Guiding antioxidant responses. Skin cells are constantly exposed to free radicals called reactive oxygen species (ROS) – a natural byproduct of cell metabolism – in response to environmental factors, such as UV light and pollution. 13,14 

The skin has a natural antioxidant defense system to combat these pro-oxidant forces, which includes enzymes such as superoxide dismutase and catalase, and antioxidants like vitamins C and E. These enzymes and antioxidants seek free radicals and neutralize them, protecting skin cells from oxidative damage that causes premature aging and skin diseases, including psoriasis, dermatitis, and acne.13,14 

Because some of these protective mechanisms weaken with aging, incorporating lifestyle practices and nutrients that promote cellular repair can help optimize skin health.

Reining in aging skin

One of the best things you can do for your skin is to protect it from the UV rays of the sun. This can include seeking shade in the afternoon, when the sun is strongest, wearing hats and sunglasses, and applying sunscreen with an SPF of 30 or higher. Experts also discourage using tanning beds.15

Other steps you can take:

1. Follow a skin-healthy diet. Consuming plant-based nutrients, such as carotenoids, flavonoids, and vitamins help neutralize free radicals and support skin health and overall well-being. Eating a plant-based diet that limits or excludes animal products and restricting processed foods might benefit your skin by reducing inflammation and oxidative stress.2

Some research suggests eating foods that contain vitamins C and E and healthy fats might improve wrinkles, skin elasticity, firmness, and pigmentation. Nutrient-rich options to consider include mangos, almonds, and avocados.2 

Polyphenols – compounds found in foods such as fruits, vegetables, tea, wine, and cocoa – have strong antioxidant properties that might support healthy skin aging.2

2. Make time for physical activity. Although being active is known to help the heart and mind, recent studies suggest that some types of exercise might also benefit the skin. One study found that cardio exercise boosted mitochondrial function. Another study found that resistance training benefited aging skin by reducing inflammation and strengthening the skin’s extracellular matrix.2

3. Try topical treatments. A wide range of facial treatments and skin-care products can help bolster skin health and appearance. Effective serums, lotions, and creams should strengthen the skin’s barrier function and encourage skin revitalization. Two main ingredients can help accomplish this: antioxidants and cell regulators. Some treatments and topicals are only available by prescription or through a dermatologist, while others are available over-the-counter.2,15

  • Retinol creams, derived from vitamin A, are some of the most used cell regulators. Retinol triggers collagen synthesis, while reducing the damaging effects of an enzyme called matrix metalloproteinase-1. 
  • Topical creams that contain the hormones estradiol and progesterone might help improve skin quality and preserve collagen during the postmenopausal years.15,16 
  • When used topically, certain antioxidants can support healthy skin. Vitamins C, B3 (as niacinamide), and E are antioxidants that promote the creation of collagen and help regulate cell metabolism and regeneration. Vitamin E has anti-inflammatory effects, smooths skin, and helps the outer layer of the skin maintain moisture. Lipoic acid is an antioxidant that might reduce facial lines and improve skin color and texture by boosting collagen synthesis.16 
  • Research shows that topical treatments containing melatonin might combat oxidative damage by seeking out harmful free radicals and preventing their formation. Melatonin can improve the function of mitochondria – where melatonin is present in high amounts – and help prevent some aging caused by pollutants and cigarette smoke.2
  • A moisturizer that contains ceramides, hyaluronic acid, or glycerin can support the skin's natural barrier function and help skin hold onto water, giving it a more youthful appearance. Opt for one with built-in sunscreen to provide benefit against harmful UV light and visible light.15,17

4. Consider chronotherapy. You might have heard of circadian rhythms. These are the body’s internal clocks that regulate various processes in the body. Most often, they’re discussed in terms of a natural sleep-wake cycle. But the skin also has circadian rhythms.15 

Chronotherapy uses the timing of these rhythms to best determine when to use a skin treatment. For example, the outermost layer of the skin has rhythmic changes that result in higher permeability at night than in the morning. Applying moisturizers and other anti-aging products in the evening allows the skin to absorb more of the treatment and garner better results.15 

Although aging is an inevitable part of life, your lifestyle choices can help keep your skin in tip-top shape. Using protective measures against damaging elements, maintaining nourishing dietary habits, engaging in physical activity, and following targeted skin-care interventions can support your skin's innate repair mechanisms. This, in turn, might slow the signs of aging and improve your skin longevity. 

A word from Thorne

In addition to topical creams that contain antioxidants, taking antioxidant supplements, including vitamin C, vitamin E, and plant polyphenols can support healthy skin aging.* And Thorne’s Collagen Plus combines the well-known benefits of collagen peptides with plant extracts that contain ceramides and polyphenols to support skin hydration, elasticity, and strength.*

Resources

  1. Gawkrodger DJ, Adern-Jones MR. Microanatomy of the skin. In: Dermatology: An Illustrated Colour Text. 7th ed. Elsevier; 2021. https://www.clinicalkey.com. [Accessed April 1, 2024.]
  2. Karimi N. Approaches in line with human physiology to prevent skin aging. Front Physiol 2023;14:1279371.
  3. Yousef H, Alhajj M, Sharma S. Anatomy. Skin (integument), epidermis. Updated 2022. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK470464/. [Accessed April 1, 2024.]
  4. Zhang Z, Zhu H, Zheng Y, et al. The effects and mechanism of collagen peptide and elastin peptide on skin aging induced by D-galactose combined with ultraviolet radiation. J Photochem Photobiol B 2020;210:111964. 
  5. NCI Dictionary of cancer terms: extracellular matrix. National Cancer Institute. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/extracellular-matrix. [Accessed April 1, 2024.]
  6. NCI Dictionary of terms: Growth factor. National Cancer Institute. https://www.cancer.gov/publications/dictionaries/cancer-terms/def/growth-factor. Accessed April 1, 2024.
  7. Shin SH, Lee YH, Rho NK, Park KY. Skin aging from mechanisms to interventions: Focusing on dermal aging. Front Physiol 2023;14:1195272.
  8. Markiewicz E, Idowu OC. DNA damage in human skin and the capacities of natural compounds to modulate the bystander signalling. Open Biol 2019;9(12):190208.
  9. Tienda-Vázquez MA, Hanel JM, Márquez-Arteaga EM, et al. Exosomes: A promising strategy for repair, regeneration and treatment of skin disorders. Cells 2023;12(12):1625. 
  10. Miller C, Crampin E, Osborne JM. Multiscale modelling of desquamation in the interfollicular epidermis. PLoS Comput Biol 2022;18(8):e1010368. 
  11. 10 surprising things about your skin. The Skin Cancer Foundation. https://www.skincancer.org/blog/10-surprising-things-about-your-skin/. [Accessed April 6, 2024.]
  12. High WA, Prok LD, eds. Structure and function of the skin. In: Dermatology Secrets. 6th ed. Elsevier; 2021. https://www.clinicalkey.com. [Accessed April 5, 2024.]
  13. Jomova K, Raptova R, Alomar SY, et al. Reactive oxygen species, toxicity, oxidative stress, and antioxidants: chronic diseases and aging. Arch Toxicol 2023;97(10):2499-2574. 
  14. Nakai K, Tsuruta D. What are reactive oxygen species, free radicals, and oxidative stress in skin diseases? Int J Mol Sci 2021;22(19):10799.
  15. How to prevent premature skin aging. American Academy of Dermatology. https://www.aad.org/news/prevent-premature-skin-aging. [Accessed April 8, 2024.]
  16. Zouboulis CC, Ganceviciene R, Liakou AI, et al. Aesthetic aspects of skin aging, prevention, and local treatment. Clin Dermatol 2019;37(4):365-372. 
  17. Saranya Wyles, M.D., Ph.D. Expert opinion. Mayo Clinic [May10, 2024]