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

Nov 18, 2024 Episode Page ↗
Overview

In this AMA sneak peek, Peter Attia, MD, and Nick Stenson introduce red light therapy. They discuss its basic science, physics, and how different wavelengths and device types affect penetration and cellular impact, preparing listeners for a detailed review of its applications.

At a Glance
3 Insights
15m 4s Duration
5 Topics
5 Concepts

Deep Dive Analysis

Introduction to Red Light Therapy AMA

Defining Red Light Therapy and Light Physics

Unique Penetration Properties of Red Light

Biological Effects of Red Light on Tissue

Red Light Therapy's Potential to Combat Aging

Red Light Therapy

Red light therapy primarily refers to light in the visible red spectrum, specifically wavelengths between 620 and 780 nanometers. It is often discussed alongside near-infrared light, which has slightly longer, invisible wavelengths.

Near Infrared Light

Near-infrared light is a form of light with wavelengths ranging from approximately 790 to 1400 nanometers, which is just beyond the visible red spectrum. Unlike red light, it is not visible to the human eye but can penetrate deeper into tissues.

Wavelength Penetration

The depth to which light can penetrate tissue is primarily determined by its wavelength; longer wavelengths penetrate deeper, though with less energy. Factors like coherence (wavelength alignment), collimation (direction alignment), and intensity (watts/joules) also influence penetration depth.

Chromophores

Chromophores are photosensitive molecules within cells or tissues that absorb light. This absorption triggers a localized chemical change or photochemical reaction, initiating the biological effects of light therapy.

Cytochrome C Oxidase (CCO)

CCO is a key component of the electron transport chain within mitochondria and is considered the primary target for red light therapy. When excited by red and near-infrared wavelengths, CCO activity increases, leading to enhanced ATP production.

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What is red light therapy?

Red light therapy involves using specific wavelengths of light, primarily in the red (620-780 nm) and near-infrared (790-1400 nm) spectrum, to elicit biological effects in tissues. These wavelengths are chosen for their unique penetration properties into the body.

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How deep can red light penetrate the body?

The penetration depth of red light varies significantly based on its delivery method: LED-delivered red light penetrates about 2-3 millimeters, infrared light 5-10 millimeters, and laser-delivered red light can reach 1-4 centimeters into the skin.

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What happens when tissue is exposed to red light?

When tissue is exposed to red light, photosensitive molecules called chromophores absorb the light, causing a photochemical reaction. The most notable effect is the excitation of cytochrome C oxidase (CCO) in mitochondria, which increases ATP production.

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What is the difference between red light and near-infrared light?

Red light is visible, with wavelengths typically between 620-780 nanometers, while near-infrared light is invisible, with longer wavelengths (790-1400 nanometers). Near-infrared light generally penetrates deeper into tissues than red light.

1. Seek Professional Medical Advice

Remember that the podcast content is for general informational purposes only and not medical advice; always seek assistance from healthcare professionals for any medical conditions and do not delay in obtaining professional medical advice.

2. Research Before Buying Red Light

Peter Atiyah advised his wife to hold off on buying red light therapy devices until research was conducted to determine their value and specific applications, suggesting a general principle of researching health interventions before purchasing.

3. Evaluate Red Light Therapy Claims

When considering red light therapy applications, remember that the more superficial the application (e.g., skin surface), the more plausible the claims of its effectiveness are likely to be, due to limited penetration depth.

As wavelengths get shorter, the energy gets more powerful.

Peter Attia

The more superficial the application, the more plausible, I think it's going to be as we go through these.

Peter Attia

To have any biological effect, the light needs to be absorbed by some photosensitive molecule within the cell or tissue that it's hitting.

Peter Attia
380 to 780 nanometers
Visible light wavelength range From purple-ish (380 nm) to red (780 nm).
620 to 780 nanometers
Red light therapy wavelength range Specific band for red light in therapy.
400 to 1100 nanometers
Phototherapy wavelength range (general) Includes visible light and near-infrared.
790 to 1400 nanometers
Near-infrared wavelength range Adjacent to red light, not visible.
2 to 3 millimeters
Penetration depth of LED-delivered red light Into skin, for common LED devices.
5 to 10 millimeters
Penetration depth of infrared light Deeper than red light due to longer wavelength.
1 to 4 centimeters
Penetration depth of laser-delivered red light Significantly deeper due to focused light energy.