#326 - AMA #65: Red light therapy: promising applications, mixed evidence, and impact on health and aging

Summary

The Peter Attia Drive: Episode #326 - AMA #65 on Red Light Therapy

Release Date: November 18, 2024

In Episode #326 of The Peter Attia Drive, host Dr. Peter Attia delves into the burgeoning topic of red light therapy (RLT) in the 65th Ask Me Anything (AMA) session. Joined by co-host Nick Stenson, the episode provides an in-depth exploration of RLT, examining its scientific foundations, varied applications, and the mixed evidence surrounding its efficacy in enhancing health and longevity.

---

1. Introduction to Red Light Therapy (00:10 - 03:51)

Overview of the Episode: Dr. Attia and Nick Stenson introduce the AMA format, highlighting their intention to address frequent questions about red light therapy—a subject of increasing interest among their listeners and even within their personal circles.

Defining Red Light Therapy: Nick Stenson begins by breaking down the fundamental physics of light, emphasizing that RLT involves specific wavelengths within the visible and near-infrared spectrum.

• Visible Light Spectrum: Ranges from approximately 380nm (purple) to 780nm (red).
• Red Light Therapy: Typically utilizes wavelengths between 620nm to 780nm.
• Near-Infrared (NIR): Extends from 790nm to 1400nm, adjacent to red light but not visible to the naked eye.

Notable Quote:

“When people talk about red light therapy, they're talking about wavelengths that are just in that red visible area of 620 to 780 nanometers.”
— Nick Stenson [03:51]

---

2. Mechanics and Penetration of RLT (06:30 - 09:43)

Penetration Depth: The effectiveness of RLT largely depends on the wavelength and the delivery method:

• LED-Based RLT: Penetrates 2 to 3 millimeters into the skin.
• Near-Infrared (NIR): Reaches 5 to 10 millimeters.
• Laser-Based RLT: Can penetrate 1 to 4 centimeters due to higher focus and coherence.

Key Factors Influencing Efficacy:

1. Coherence: Alignment of light waves enhances penetrance.
2. Collimation: Directionality of light beams prevents spreading, allowing deeper penetration.
3. Intensity: Measured in watts or joules, it determines the energy delivered.

Notable Quote:

“If red light is being delivered by LEDs, it's going to be able to penetrate about 2 to 3 millimeters into skin.”
— Nick Stenson [08:15]

Takeaway: RLT's benefits may be more plausible for applications targeting superficial tissues due to limited penetration depths.

---

3. Biological Mechanisms of RLT (09:43 - 11:19)

Cellular Interaction: For RLT to elicit biological effects, light must be absorbed by photosensitive molecules called chromophores within cells.

• Cytochrome C Oxidase (CCO): A critical chromophore located in mitochondria, involved in the electron transport chain.
• Effect of RLT: Red and NIR wavelengths can excite CCO, enhancing ATP production and potentially improving cellular function.
• Contrast with Other Wavelengths: Shorter wavelengths like blue and green light may decrease CCO activity and ATP production.

Notable Quote:

“Red light and near infrared wavelengths do seem to excite cytochrome C oxidase, and its activity then increases subsequent ATP production.”
— Nick Stenson [10:00]

Implications: The modulation of mitochondrial activity suggests potential applications of RLT in areas like energy metabolism, cellular repair, and overall cellular health.

---

4. Evaluating Claims and Applications of RLT (11:19 - 13:23)

Focus on Aging: Dr. Attia initiates a discussion on the potential of RLT to combat aging, a central claim among proponents. The conversation is poised to dissect various applications, including skin health, wound healing, hair loss, eye health, exercise performance, metabolic health, fat loss, inflammation, injury rehabilitation, and menstrual cramps.

Methodology: The hosts emphasize a detailed analysis of existing literature for each application, assessing the validity and strength of evidence supporting RLT's efficacy.

Note: While the transcript transitions into a promotional segment around [11:33], it underscores the commitment of the podcast to provide evidence-based insights rather than unverified claims.

---

5. Conclusion and Takeaways

Although the transcript provided concludes before a comprehensive review of all applications, the foundational discussion establishes a critical framework for evaluating red light therapy:

• Scientific Basis: RLT operates within specific wavelengths that interact with cellular components, primarily affecting mitochondrial function.
• Application Scope: The depth of light penetration is a limiting factor, making RLT potentially more effective for superficial treatments.
• Evidence Assessment: A rigorous examination of existing studies is essential to discern the true benefits and limitations of RLT across various health domains.

Final Notable Quote:

“As a general rule of thumb, the more superficial the application, the more plausible I think it's going to be.”
— Nick Stenson [09:43]

---

Additional Information

For listeners interested in a deeper dive into AMA #65 on red light therapy, full access is available through Premium membership. This includes comprehensive show notes, exclusive AMA episodes, detailed newsletters, and more.

Subscribe and Learn More: Visit PeterAttiaMD.com to subscribe and explore member-only benefits. Connect with Dr. Attia on social media platforms such as YouTube, Instagram, and Twitter (@PeterAttiaMD).

Disclaimer: The content discussed in this podcast is for informational purposes only and does not constitute medical advice. Always consult healthcare professionals for medical concerns.

---

This summary encapsulates the key discussions from the provided transcript of Episode #326 - AMA #65 on Red Light Therapy. For the complete conversation and detailed analyses of each application, subscribing to The Peter Attia Drive is recommended.

Transcript

[Nick Stenson]

Hey everyone.

[Peter Attia]

Welcome to a Sneak Peek, Ask Me Anything or AMA episode of the Drive podcast. I'm your host, Peter Attia. At the end of this short episode.

[Nick Stenson]

I'll explain how you can access the.

[Peter Attia]

AMA episodes in full, along with a.

[Nick Stenson]

Ton of other membership benefits we've created.

[Peter Attia]

Or you can learn more now by going to Peter attiamd.com forward/subscribe. So without further delay, here's today's sneak peek of the Ask Me Anything episode.

[Nick Stenson]

Welcome to Ask me anything episode 65. I'm once again joined by my co host Nick Stenson. In today's episode, we cover red light therapy as a topic we get asked about all the time. In fact, my wife asks me about it all the time, so it was clear that it was time for an ama. In this conversation, we lay the foundation for what red light therapy is and why there is such an emphasis on it. We then break down the various forms of red light therapy and their various treatments into whether or not I think they are beneficial. In other words, we go through each application and review the data for them. So these include red light therapy for aging in general, skin health and acne, wound healing, hair loss, eye health, exercise performance and recovery, metabolic health, general weight loss, spot fat loss, inflammation, injury rehab, and menstrual cramps for women.

So in other words, we go through.

Each of these and do a detailed analysis of the literature. We close this conversation by summarizing my overall takeaways for each use case and explain via a summary table that we created that breaks down everything you might want to know. To understand this. If you're a subscriber and you want to watch the full video of this podcast, you can find it on the Show Notes page. If you're not a subscriber, you can watch a sneak peek of the video on our YouTube page. So without further delay, I hope you enjoy AMA number 65.

[Peter Attia]

Peter, welcome to another AMA. How you doing?

[Nick Stenson]

Good. Thanks for having me back.

[Peter Attia]

Anytime, anytime. So today's ama we are going to focus on a single topic which is red light therapy. This is something we get asked about a lot. Not only questions from the website and subscribers, but I know through your patients as well. And so we compiled all these questions and through this conversation hopefully going to cover what red light therapy is, how it can work, deep dive into some various claims out there around red light therapy. This can include potential effect on skin health, wound healing, hair loss, eyesight, exercise performance and recovery, metabolic health, fat loss, inflammation, chronic pain, and a lot more. So with all that said Anything you want to add before we get rolling into it?

[Nick Stenson]

Two unrelated things. I notice you have a little visitor for the podcast today hanging out with you there. Hopefully he's interested and this is something he'll like. And secondly, I would add that my wife is specifically asking me these questions, so she's very keen to buy a whole bunch of red light things, and I asked her to just hold off until we did the research for this episode so that we could at least have a sense of if there's value there where it is. I don't know if she's a subscriber, though, so if she's not, this might be the one that she subscribes for.

[Peter Attia]

I respect that when your wife asks you medical questions, you say, let me send you a podcast episode instead of telling her the answer like everyone else. So it's good to know you practice what you preach, even through your direct family. Okay, first question. I think it's going to be helpful to just explain. When we say red light therapy, what does that even mean?

[Nick Stenson]

Yeah, you can't do this without at least having some understanding of the physics. And the principles that define light. And waves come up over and over and over again as you try to evaluate the plausibility of the claims that are made here. So when we're sitting here looking out at the world, we're looking at light, and there's visible colors of light. Maybe I should take a step back. Light exists as waves, and they're very short waves, to be clear. So sound waves are really, really long. Light waves are really, really short. And then obviously waves can get much, much shorter. And you can get into uv, which we've talked about in detail on a previous podcast. And then even shorter than that would be X rays, and then even shorter than that, or gamma rays. So as wavelengths get shorter, the energy gets more powerful. But if we just focus on light, visible light runs the gamut from about 380nm, which would be purple ish, and then all the way at the longest end, about twice that. 780nm is where red light is. So when people talk about red light therapy, they're mostly talking about light that is in that very narrow band. So, for example, again, a white light is giving you all mixed across that entire range. Red light would be more narrowly focused. It's also important to understand that, and we'll talk about this a little bit today. Phototherapy in general involves wavelengths across that entire band of visible light, but it also includes something called near infrared, so that Basically runs the gamut from about 400 to 1100 nanometers. So I think the easiest way to think about this is red light therapy, which it runs about 620 to 780 nanometers. And then near infrared, which is right adjacent to that. The next thing up in terms of length, which is about 790 to 1400. So again, if you forget everything else, just remember when people talk about red light therapy, they're talking about wavelengths that are just in that red visible area of 620 to 780. And then often they talk about near infrared as well, which is not visible, to be clear, you don't see it, and it's just a little bit longer. 790 to 1400 nanometers. We'll come back to this over and over again because there are some instances where the fact that you can't see it might actually make it a little more dangerous.

[Peter Attia]

Double clicking on red light therapy. Can we explain a little bit more about what is special about it and why there's so much emphasis on it as talked about for the various claims that we'll speak about today.

[Nick Stenson]

People who listened to our podcast on ultraviolet light may recall a distinction I made between UVA and uvb, which came down to the degree of penetration. And so similarly, when you think about red light therapy and you remember that the longer a wavelength, the more it can penetrate, albeit with less energy. What makes red light interesting is it is sort of at this sweet spot where it has some capacity to penetrate more so than other forms of visible light. That's sort of part of what makes this interesting. Now, the exact depth that's reached by the red light or the near infrared is kind of a function of how the light beams are organized. So what is the amount of coherence, which is how much do the wavelengths line up with each other? So if the wavelengths are all coherent, the peaks and valleys are in the same place, it's going to have more penetrance. And then what's the extent to which they're all aligned in the exact same direction? That's called collimation. So in other words, the light isn't spreading, but rather it's all pointed in the exact same direction. And then finally, you have the intensity. And we'll talk a little bit about the difference between watts and joules, because if people are looking at these devices, sometimes they give you information in watts, and sometimes they give you information in joules, which, of course, there's a very clear relationship between them. And of course, broadly speaking, energy matters as well. So when you take all of that into account, though, the really important principle that I think it's perhaps missed when people evaluate these things is that for the most part, red light can't penetrate nearly as much as people think it can. Okay, if red light is being delivered by LEDs, which is the most common way that it is, it's going to be able to penetrate about 2 to 3 millimeters into skin. Now, infrared light can go a little bit deeper because, remember, it's a longer wavelength and it can reach probably 5 to 10 millimeters. Now, if red light is delivered by a laser, because again, you now have a more focused form of light energy, it could penetrate significantly higher than that. It could go from 1 to 4 centimeters. So, again, keep in mind the way that the light is organized plays a significant role in the depth that it can penetrate. Now, if you start to think about some of the applications we're going to talk about, when you start to think about red light therapy, just keep in the back of your mind. If something can only penetrate 1 to 3 millimeters, it's going to be difficult for it to have some of the profound effects that are sometimes claimed. Even if something can penetrate 10 millimeters or a centimeter, which would be quite deep, it's not clear that that's going to be able to have a significant effect. And so, as a general rule of thumb, the more superficial the application, the more plausible I think it's going to be.

[Peter Attia]

As we go through these last foundational question before we get to the various claims, and where this could be beneficial or not is in general, what happens when the tissue is exposed to red light?

[Nick Stenson]

This is an important and as you said, foundational question. So to have any biologic effect, the light needs to be absorbed by some photosensitive molecule within the cell or tissue that it's hitting. And so the absorption of light by these photosensitive molecules, which are called chromophores, cause a localized chemical change or a photochemical reaction. Now, the most interesting of these is probably something called cytochrome C oxidase, or cco. It's a component of the electron transport chain within mitochondria. And generally speaking, most people who are proponents of red light therapy point to cytochrome C oxidase, or cco as the main target and therefore the mediating effect of the biologic impact of red light. So red light and near infrared wavelengths do seem to excite cytochrome C oxidase, and its activity then increases subsequent ATP production. Conversely, blue and green wavelengths. Remember, these are shorter, less penetrant, but more powerful, seem to decrease the activity of CCO and subsequently decrease ATP production.

[Peter Attia]

Now kind of getting into various claims of where red light therapy can be beneficial or not. I think it helped to maybe start with what do we know about the idea that red light therapy can combat aging as a whole?

Thank you for listening to today's Sneak peek AMA episode of the Drive. If you're interested in hearing the complete version of this ama, you'll want to become a Premium member. It's extremely important to me to provide all of this content without relying on paid ads to do this. Our work is made entirely possible by our members and in return we offer exclusive member only content and benefits above and beyond what is available for free. So if you want to take your knowledge of this space to the next level, it's our goal to ensure members get back much more than the price of the subscription. Premium membership includes several benefits. First, comprehensive podcast show notes that detail every topic, paper, person and thing that we discuss in each episode and the word on the street is Nobody's Show Notes Rival hours. Second, monthly Ask Me Anything or AMA episodes. These episodes are comprised of detailed responses to subscriber questions typically focused on a single topic, and are designed to offer a great deal of clarity and detail on topics of special interest to our members. You'll also get access to the show notes for these episodes, of course. Third, delivery of our Premium newsletter, which is put together by our dedicated team of research analysts. This newsletter covers a wide range of topics related to longevity and provides much more detail than our free weekly newsletter. Fourth, access to our private Podcast feed that provides you with access to every episode, including AMAs sans the spiel you're listening to now and in your regular podcast feed. Fifth, the Qualies, an additional member only podcast we put together that serves as a highlight reel featuring the best excerpts from previous episodes of the Drive. This is a great way to catch up on previous episodes without having to go back and listen to each one of them and finally, other benefits that.

[Nick Stenson]

Are added along the way.

[Peter Attia]

If you want to learn more and access these member only benefits, you can head over to PeterAtiaMD.com subscribe you can also find me on YouTube, Instagram and Twitter, all with the handle PeterAtiaMD. You can also leave us a review on Apple Podcasts or whatever podcast player YouTube use. This podcast is for general informational purposes only and does not constitute the practice of medicine, nursing or other professional healthcare services, including the giving of medical advice, no doctor patient relationship is formed. The use of this information and the materials linked to this podcast is at the user's own risk. The content on this podcast is not intended to be a substitute for professional medical advice, diagnosis or treatment. Users should not disregard or delay in obtaining medical advice from any medical condition they have, and they should seek the assistance of their healthcare professionals for any such conditions. Finally, I take all conflicts of interest very seriously. For all of my disclosures and the companies I invest in or Advise, please visit PeterAtiaMD.com about where I keep an up to date and active list of all disclosures.