In recent years, light-based therapies have gained significant attention in dermatology and cosmetic science for their non-invasive benefits. Among these, red and near-infrared (NIR) light therapy has emerged as a promising approach to improve skin health and combat signs of aging. A study by Li et al. (2021) published in the International Journal of Cosmetic Science explored the effects of combining low-level red (633 nm) and near-infrared (830 nm) light on human skin cells in vitro, revealing compelling evidence of enhanced collagen and elastin production. This article synthesizes the findings of this study to explain how red and NIR light therapy can benefit the skin, focusing on its mechanisms, applications, and potential implications for anti-aging skincare.
Understanding Red and Near-Infrared Light Therapy
Red and NIR light therapy, also known as photobiomodulation, uses specific wavelengths of light to stimulate cellular activity without generating heat. Unlike harmful ultraviolet (UV) rays, these wavelengths (600–1000 nm) penetrate deeper into the skin layers, reaching the dermis where collagen and elastin—the proteins responsible for skin elasticity and firmness—are produced by fibroblasts. The study by Li et al. (2021) specifically investigated the combined effects of 633 nm red light and 830 nm NIR light, two wavelengths known for their ability to activate cellular energy production and promote tissue repair.
Key Findings from Li et al. (2021)
The study aimed to determine whether low-level red and NIR light could enhance collagen and elastin expression in human skin cells. Using in vitro models, the researchers exposed fibroblasts and skin explants to daily 30-minute treatments of combined red and NIR light for seven days. The results were striking:
1. Genetic Activation: The treatment significantly increased the expression of genes responsible for collagen (COL1A1, COL3A1) and elastin (ELN) production. This genetic upregulation suggests that light therapy directly influences the fibroblasts’ “blueprint” for producing these structural proteins.
2. Protein Synthesis: At the protein level, the researchers observed a notable increase in procollagen type I and elastin. This indicates that the genetic changes translated into tangible improvements in the skin’s extracellular matrix, the framework that supports skin structure.
3. Energy Production: The combination of red and NIR light also boosted ATP (adenosine triphosphate) production in fibroblasts. ATP is the cell’s primary energy source, and increased levels likely fuel the enhanced collagen and elastin synthesis.
These findings collectively demonstrate that red and NIR light therapy can biologically rejuvenate skin cells by stimulating key processes linked to skin elasticity and resilience.
Mechanisms of Action
To understand why red and NIR light have such effects, it is essential to delve into their interaction with skin cells. The study highlights two primary mechanisms:
1. Mitochondrial Activation:
Mitochondria, the “powerhouses” of cells, contain a protein called cytochrome c oxidase, which absorbs red and NIR light. This absorption triggers a chain reaction that increases ATP production, providing energy for cellular functions like collagen synthesis. In Li et al.’s (2021) study, the ATP boost correlated with higher collagen and elastin levels, suggesting a direct energy-dependent relationship.
2. Anti-Inflammatory and Antioxidant Effects:
While the study focused on collagen and elastin, red and NIR light also reduce inflammation and oxidative stress. Chronic inflammation and free radical damage contribute to collagen breakdown and aging. By mitigating these factors, light therapy creates an environment conducive to tissue repair and regeneration.
Implications for Skin Health and Anti-Aging
The results of Li et al. (2021) offer exciting possibilities for skincare and dermatology. Here’s how red and NIR light therapy could benefit the skin:
1. Improved Skin Elasticity:
Collagen and elastin are critical for maintaining skin firmness and reducing wrinkles. The study’s demonstration of increased protein synthesis suggests that regular light therapy could enhance skin elasticity, making it appear smoother and more youthful.
2. Enhanced Wound Healing:
Fibroblasts play a key role in wound repair by producing collagen. The ATP boost from light therapy may accelerate this process, potentially reducing healing time and scarring. While the study did not directly test wound healing, the increased collagen production provides a strong mechanistic basis for this application.
3. Non-Invasive Alternative to Cosmetic Procedures:
Unlike injectables or surgical interventions, light therapy is painless, non-invasive, and free from significant side effects. This makes it an attractive option for individuals seeking subtle anti-aging improvements without downtime.
4. Synergy with Skincare Products:
Light therapy could enhance the efficacy of topical treatments. For example, combining a collagen-boosting serum with light exposure might amplify results by targeting both the surface and deeper layers of the skin.
Limitations and Considerations
While the study by Li et al. (2021) provides robust evidence, it is important to acknowledge its limitations:
1. In Vitro Model:
The research was conducted using isolated skin cells and explants, not live human subjects. While in vitro studies offer controlled environments, they do not fully replicate the complexity of the human body. Further clinical trials are needed to confirm these effects in vivo.
2. Dose and Duration:
The optimal dose and frequency of light therapy remain unclear. The study used daily 30-minute sessions for seven days, but real-world applications may require longer or more frequent treatments. Individual variations in skin type and response must also be considered.
3. Device Variability:
The study used specific wavelengths (633 nm and 830 nm) and intensities. Not all commercial devices adhere to these parameters, which could affect outcomes. Users should seek devices validated by scientific research.
Practical Applications and Safety
Red and NIR light therapy is already available in clinical settings and as at-home devices. Here’s what users should know:
• Clinical Settings: Dermatologists and aesthetic clinics often use professional-grade LED panels or lasers to deliver precise doses of light. These sessions are typically spaced weekly or biweekly.
• At-Home Devices: Consumer-friendly options like LED masks and handheld devices allow users to incorporate light therapy into their skincare routines. However, it is crucial to follow manufacturer instructions to avoid overexposure.
• Safety: When used correctly, red and NIR light therapy is generally safe. Mild side effects like temporary redness or warmth may occur, but severe reactions are rare. Individuals with photosensitive conditions or implanted metal devices should consult a healthcare provider before use.
Conclusion
The study by Li et al. (2021) underscores the potential of red and NIR light therapy to revitalize skin health by stimulating collagen and elastin production. While further research is needed to confirm its effects in humans and optimize treatment protocols, the findings provide a solid foundation for this non-invasive approach. As the field of photobiomodulation advances, red and NIR light therapy may become a cornerstone of anti-aging skincare, offering a natural, science-backed solution for healthier, more radiant skin.
References
Li, W. H., Seo, I., Kim, B., Fassih, A., Southall, M. D., & Parsa, R. (2021). Low-level red plus near infrared lights combination induces expressions of collagen and elastin in human skin in vitro. International Journal of Cosmetic Science, 43(3), 311–320. https://doi.org/10.1111/ics.12698
