Introduction
In this AMA (Ask Me Anything) episode of The Drive Podcast, host Peter Attia dives deep into the world of red light therapy, joined by his co-host Nick Stenson. This episode addresses numerous questions from listeners, covering what red light therapy is, its effectiveness, and its various applications. Peter and Nick thoroughly discuss the science behind red light therapy and evaluate its validity for different health claims ranging from skin health to exercise performance.
Key Takeaways
- Red light therapy basics: Red light falls between 620 to 780 nanometers, while near-infrared runs from 790 to 1400 nanometers, each with unique properties for therapy.
- Limited penetration: Red light only penetrates 2-3 mm into the skin with LED, but can reach deeper with laser—up to 4 cm.
- Biological effects: Red light affects ATP production by exciting cytochrome C oxidase in mitochondria, potentially impacting aging and healing.
- Mixed effectiveness: The efficacy of red light therapy varies widely depending on the application—more superficial uses tend to be more plausible.
Key Points
Understanding Red Light Therapy
Peter begins by explaining the basic principles of red light therapy, focusing on the physics behind light wavelengths and why certain wavelengths are considered for therapeutic uses. Red light therapy uses visible red light within a very narrow band, specifically wavelengths between 620 to 780 nanometers. Often, people also refer to near-infrared light as part of this therapy, which lies between 790 and 1400 nanometers. The episode highlights that the length of these light waves determines their ability to penetrate the skin and potentially exert biological effects.
The hosts also draw comparisons between red light and ultraviolet light, pointing out that longer wavelengths tend to penetrate more deeply, although they also carry less energy. This distinction explains why red light and near-infrared are often used to try to reach tissues under the skin. For example, red light delivered by LEDs can penetrate only a few millimeters, while laser-delivered light, which is more focused, can go significantly deeper, possibly even reaching up to 4 cm into the skin. Peter underscores that understanding these details is crucial when evaluating claims about red light therapy's effectiveness.
Mechanism and Claims of Red Light Therapy
Peter dives into the biological mechanisms, focusing particularly on how light interacts with tissues. The key mechanism involves light being absorbed by photosensitive molecules, or chromophores, such as cytochrome C oxidase (CCO) in mitochondria. This component plays a significant role in the electron transport chain, and thus, in ATP production. When red light or near-infrared wavelengths stimulate CCO, it leads to increased ATP production, which is the main basis for the purported benefits of red light therapy.
The discussion covers claims about red light therapy’s effectiveness for a wide range of uses. Some of the more superficial claims, such as improving skin health, seem plausible, given that red light can penetrate a few millimeters into the skin. However, for more profound claims, such as fat loss or deep tissue healing, Peter is skeptical about their validity, pointing out the physical limitations of light penetration and energy delivery. The episode maintains a critical view, suggesting that while red light therapy may have some benefits, they are largely limited to very superficial applications.
Evaluating Use Cases: From Aging to Performance
The hosts break down various use cases for red light therapy, covering its impact on aging, skin health, wound healing, hair loss, eye health, exercise performance and recovery, metabolic health, and more. For aging and skin health, red light therapy may promote collagen production and improve skin texture. However, Peter points out that the degree of effectiveness often depends on factors like light coherence, intensity, and the method of delivery (LED vs. laser). The deeper penetration required to achieve meaningful biological changes for aging makes red light less effective beyond superficial improvements.
For exercise performance and recovery, Peter explains that while red light and near-infrared may have some effect on mitochondrial function and ATP production, the data is inconsistent. He mentions that any observed benefits may be due to the placebo effect, and that more research is needed to verify these claims. Moreover, for areas such as fat loss and spot reduction, the discussion is largely dismissive—Peter makes it clear that the science does not support the claims that red light can effectively target fat cells or lead to significant weight loss without additional interventions.
Safety and Practical Applications
The episode also touches on the safety aspects of red light therapy. Peter explains that while red light therapy is generally considered safe, there is a potential risk when using near-infrared light, which can be more dangerous since it is invisible and people might overexpose themselves without realizing it. He emphasizes the need for caution, particularly with devices that deliver high-intensity near-infrared light, as users cannot see the light and may inadvertently cause harm.
Finally, the hosts provide a practical framework for evaluating whether or not red light therapy is worth trying. They suggest that individuals should manage their expectations and understand the limitations based on the depth of penetration and the specific type of device used. For example, LED devices that are marketed for home use are unlikely to have the same power or effect as medical-grade laser devices. Peter also shares a summary table, available to subscribers, that breaks down the data for different applications, providing a clearer picture of where red light therapy might offer real benefits and where it does not.
Conclusion
In this AMA episode, Peter and Nick present a balanced view of red light therapy, highlighting both its potential and its limitations. The key takeaway is that while red light therapy may have some benefits—particularly for superficial skin-related conditions—its effectiveness for deeper, more complex issues remains uncertain. Listeners are encouraged to approach red light therapy with an open but critical mind, understanding that its utility is largely confined to specific, surface-level applications. The discussion is both informative and cautionary, providing the audience with the knowledge needed to make informed decisions about incorporating red light therapy into their health routines.