Understanding the Benefits of Antioxidants for Skin Ageing

The Role of Antioxidants in Skin Health

Antioxidants play a crucial role in preventing or slowing the process of cutaneous ageing. While consuming antioxidants through food and supplements can be beneficial, there is growing evidence that topical use of antioxidants offers significant clinical advantages.

Many topical rejuvenation formulations contain vitamins and their derivatives, which perform both protective and reparative functions. One such vitamin is B3, which encompasses several related molecules, including nicotinic acid (niacin) and niacinamide.

Importance of Niacinamide

These molecules are vital components of the enzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). They play critical roles in mitochondrial oxidative phosphorylation. Niacinamide has long been established for its anti-inflammatory effects, particularly in treating inflammatory acne vulgaris.

Recent studies show that niacinamide can mitigate the skin's inflammatory response to environmental stressors, such as UV radiation and pollution. It does this by inhibiting cellular senescence and maintaining epidermal homeostasis.

Clinically, topical niacinamide is well tolerated by facial skin. It provides several benefits for ageing skin, including improved barrier function and a decrease in signs of facial photo-ageing. These signs include texture, pore size, hyperpigmented spots, red blotchiness, sallowness, and reduced sebum production. Although the rejuvenating effects of niacinamide are comparable to those of tretinoin, topical tretinoin 0.025% remains a more potent option. Niacinamide is reported to be one-third to one-fifth as effective at improving wrinkles and hyperpigmentation.

Vitamin C: A Potent Antioxidant

Vitamin C is another powerful water-soluble antioxidant that can rejuvenate photoaged skin through topical application. However, one of the main challenges with vitamin C products is their instability. The most stable formulation is L-ascorbic acid with a pH of 3.5, as acidity enhances its penetration and stability.

When applied topically, ascorbic acid can significantly improve photo-ageing scores for the cheeks and perioral area, reducing skin roughness and wrinkling. These clinical improvements are believed to be mediated through the proliferation of keratinocytes and fibroblasts. Additionally, there is increased expression of collagen I and III, newly synthesized elastic fibres in the papillary dermis, and elevated levels of ECM protease inhibitors like TIMPS.

Moreover, topical ascorbic acid enhances collagen fibre organization and cross-linking, which together improve the strength and stability of the extracellular matrix (ECM). Vitamin C is also effective in treating hyperpigmentation. It inhibits the enzyme tyrosinase, which is responsible for converting tyrosine to melanin. By interacting with copper ions at tyrosinase active sites, vitamin C reduces melanin synthesis. Therefore, topical vitamin C can help improve pigmentary changes associated with sun exposure, although high-quality clinical trial data are still lacking.

Strategies for Managing Skin Ageing

Skin ageing is inevitable, but various measures can help reduce its impact, particularly those caused by environmental factors. Preventing UV-induced accelerated skin ageing is essential. Regular use of broad-spectrum photoprotection should be a fundamental part of any skincare routine. This can be supplemented with topical antioxidant products that provide additional photoprotection and help neutralise other sources of oxidative stress, such as air pollution.

Optimising barrier function with simple emollients is also crucial. A healthy stratum corneum serves as the first line of defence against environmental assault. Topical retinoids and certain peptides not only demonstrate epidermal effects but also promote dermal repair. They have a more profound clinical impact on deeper cutaneous wrinkles, although noticeable cellular changes will take months rather than days.

Setting Realistic Expectations

Furthermore, it is vital to have realistic expectations regarding the overall impact on facial morphology. Even the best skin rejuvenation programmes cannot mitigate more dramatic volumetric changes due to underlying fat redistribution, atrophy, and deeper bone loss.

For more information, please refer to the full article, which is taken from:

Tamara W Griffiths, Rachel E B Watson, Abigail K Langton, Skin ageing and topical rejuvenation strategies, British Journal of Dermatology, Volume 189, Issue Supplement_1, October 2023, Pages i17–i23, https://doi.org/10.1093/bjd/ljad282