Red Light Therapy

Photobiomodulation (PBM), commonly known as red light therapy, is an emerging non-pharmacological intervention with promising effects on cognitive enhancement and potential implications for healthy aging and longevity.

Mechanisms of Action:

PBM uses red or near-infrared light (typically 630–1064 nm) to stimulate cellular processes, primarily by activating cytochrome c oxidase in the mitochondrial respiratory chain. This leads to increased ATP production, improved mitochondrial function, and downstream effects such as reduced oxidative stress, anti-inflammatory responses, and enhanced neurogenesis and synaptogenesis. These mechanisms are central to PBM’s neuroprotective effects and its ability to modulate brain functional reorganization.[1][2][3]

Cognitive Enhancement:

Multiple systematic reviews and meta-analyses of randomized controlled trials demonstrate that PBM can significantly improve global cognitive function, working memory, attention, and executive function in both healthy older adults and those with cognitive impairment, including mild cognitive impairment and Alzheimer’s disease.[4][5][6] The effect sizes are moderate to large, with the strongest benefits observed in populations with existing cognitive deficits. For example, a 2025 meta-analysis found PBM improved global cognition (SMD = 0.66), working memory (SMD = 1.41), and executive function (SMD = -1.10) compared to controls.[6] Protocols most commonly use transcranial application with near-infrared light (810 nm), irradiance of 20–25 mW/cm², and fluence of 1–10 J/cm², often targeting the prefrontal cortex.[5][7]

Effects on Aging and Longevity:

Preclinical studies in animal models show that PBM can improve spatial, episodic-like, and social memory, reduce amyloid burden, and modulate genes associated with neuroprotection, neuroinflammation, and oxidative stress.[8][9][10][2] In mice, daily transcranial PBM for 30 days altered the expression of over 1,000 genes in the cortex and hippocampus, including those involved in Alzheimer’s disease pathways, and reduced amyloid precursor protein concentration.[9] These molecular changes suggest PBM may help inhibit neurodegeneration and maintain normal brain conditions.

In humans, PBM has demonstrated improvements in working memory, cognitive inhibition, and lexical/semantic access in healthy aged individuals, and more pronounced effects in those with Alzheimer’s disease or mild cognitive impairment.[8][4][5][6] PBM also shows neuroprotective, anti-inflammatory, immunomodulatory, and hemodynamic effects, which are relevant to aging and age-related diseases.[8][11][3] However, while PBM favorably modulates pathways linked to aging and neurodegeneration, direct evidence for lifespan extension in humans is not yet available.[11][3]

Safety and Practical Considerations:

PBM is considered safe and well-tolerated, with no significant adverse effects reported in clinical trials. The National Institute on Aging workshop concluded that PBM is a promising, inexpensive, and safe intervention for age-related diseases and cognitive decline, but emphasized the need for standardized protocols and further research to optimize its use.[3]

Summary:

PBM (red light therapy) is supported by moderate-to-strong evidence for cognitive enhancement and neuroprotection in aging populations, with molecular and clinical data suggesting benefits for brain health and resilience. While its role in extending human lifespan remains unproven, PBM’s effects on mitochondrial function, neuroinflammation, and gene expression position it as a promising adjunct for healthy aging. Standardized protocols and long-term studies are needed to clarify its impact on longevity and to guide clinical application.

Key Takeaway:

PBM is a safe, non-invasive intervention that can enhance cognitive function and may support healthy brain aging, but its direct effects on human longevity require further investigation.[8][11][4][5][6][3]

References

1. Photobiomodulation Therapy on Brain: Pioneering an Innovative Approach to Revolutionize Cognitive Dynamics. Nairuz T, Sangwoo-Cho, Lee JH. Cells. 2024;13(11):966. doi:10.3390/cells13110966.

2. The Molecular Mechanisms of Action of Photobiomodulation Against Neurodegenerative Diseases: A Systematic Review. Bathini M, Raghushaker CR, Mahato KK. Cellular and Molecular Neurobiology. 2022;42(4):955-971. doi:10.1007/s10571-020-01016-9.

3. Light Buckets and Laser Beams: Mechanisms and Applications of Photobiomodulation (PBM) Therapy. Frankowski DW, Ferrucci L, Arany PR, et al. GeroScience. 2025;47(3):2777-2789. doi:10.1007/s11357-025-01505-z.

4. Effectiveness of Photobiomodulation for People With Age-Related Cognitive Impairment: A Systematic Review and Meta-Analysis. Gao Y, An R, Huang X, et al. Lasers in Medical Science. 2023;38(1):237. doi:10.1007/s10103-023-03899-8.

5. Can Transcranial Photobiomodulation Improve Cognitive Function? A Systematic Review of Human Studies. Lee TL, Ding Z, Chan AS. Ageing Research Reviews. 2023;83:101786. doi:10.1016/j.arr.2022.101786.

6. Photobiomodulation Effects on Cognitive Function - A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Zhu Z, Zhang R, Chi Y, Li W, Gong W. Lasers in Medical Science. 2025;40(1):234. doi:10.1007/s10103-025-04484-x.

7. Photobiomodulation as a Promising New Tool in the Management of Psychological Disorders: A Systematic Review. Gutiérrez-Menéndez A, Marcos-Nistal M, Méndez M, Arias JL. Neuroscience and Biobehavioral Reviews. 2020;119:242-254. doi:10.1016/j.neubiorev.2020.10.002.

8. Photobiomodulation in the Aging Brain: A Systematic Review From Animal Models to Humans. Rodríguez-Fernández L, Zorzo C, Arias JL. GeroScience. 2024;46(6):6583-6623. doi:10.1007/s11357-024-01231-y.

9. Transcranial Photobiomodulation Therapy With 808 nm Light Changes Expression of Genes and Proteins Associated With Neuroprotection, Neuroinflammation, Oxidative Stress, and Alzheimer's Disease: Whole RNA Sequencing of Mouse Cortex and Hippocampus. Li B, Golovynska I, Stepanov YV, et al. PloS One. 2025;20(7):e0326881. doi:10.1371/journal.pone.0326881.

10. Photobiomodulation for Neurodegenerative Diseases: A Scoping Review. Shen Q, Guo H, Yan Y. International Journal of Molecular Sciences. 2024;25(3):1625. doi:10.3390/ijms25031625.

11. Photobiomodulation for the Aging Brain. Cardoso FDS, Gonzalez-Lima F, Gomes da Silva S. Ageing Research Reviews. 2021;70:101415. doi:10.1016/j.arr.2021.101415.