Red Light: A Metabolic Switch

Written By Dr. Alexis Cowan, PhD 

Health depends in part on the body’s ability to produce and use energy efficiently over time. Mitochondria, the organelles found in almost every cell, play a central role in this process by helping convert nutrients and oxygen into ATP, the cell’s primary energy currency.

Most conversations about energy production focus almost entirely on food. While nutrients clearly matter, research in photobiomodulation suggests that light exposure may also influence how efficiently mitochondria function, especially in relation to red and near-infrared wavelengths.

To understand why this matters, it helps to briefly review how mitochondria work. These structures contain an inner and outer membrane, along with the electron transport chain, a series of protein complexes embedded in the inner membrane that help shuttle electrons, move protons, and create the electrochemical gradient needed to power ATP synthase.

Complexes I through IV help move electrons and pump protons into the intermembrane space, creating stored potential energy. Complex V, also known as ATP synthase, uses that gradient to generate ATP, which cells then use to power countless biological processes.

The electrons and protons that feed this system come largely from food, including carbohydrates, fats, and amino acids. But emerging research suggests that light may also influence mitochondrial performance, making the process of energy production more efficient under certain conditions.

How Red and Near-Infrared Light May Influence Mitochondria

Researchers have long studied how long-wavelength light in the red to near-infrared range may interact with mitochondrial pathways. In particular, wavelengths in the roughly 650-900 nm range have been associated with photobiomodulation effects involving cytochrome c oxidase and related energy-producing processes.

Some proposed mechanisms include support for electron transport chain activity and changes in the water layer surrounding ATP synthase that may improve the efficiency of its rotary function. While the exact mechanisms continue to be studied, the broader idea is that red and near-infrared light may help mitochondria perform more effectively under the right conditions.

The 2024 Study on Red Light and Blood Glucose Response

A 2024 paper published in the Journal of Biophotonics by Powner and Jeffery explored whether supporting mitochondrial function with 670 nm red light might influence glucose handling in healthy adults. The study used an oral glucose tolerance test to compare blood glucose response in participants who received light exposure versus those who did not.

Thirty healthy participants, average age around 40, were split into two groups of 15. One group received 15 minutes of 670 nm red light exposure to the upper back at an intensity of about 40 mW/cm² from approximately 16 inches away, 45 minutes before the glucose test, while the control group followed the same protocol with the light not switched on.

Blood samples were collected every 15 minutes for two hours after the glucose drink. According to the study abstract, 15 minutes of 670 nm light reduced the overall blood glucose elevation integrated over two hours by 27.7%, and reduced maximum glucose spiking by 7.5% in the healthy adults studied.

These findings are interesting and suggest that red light exposure may influence acute glucose response under controlled conditions. At the same time, this was a relatively small study in healthy individuals, so the results are best viewed as promising early evidence rather than a stand-alone clinical recommendation.

What This May Mean in Practical Terms

The study points to the possibility that red light exposure could support metabolic function in ways that go beyond skin appearance or recovery-oriented use cases. More broadly, it reinforces the idea that the light environment may play a role in mitochondrial health and overall physiology.

Modern life tends to reduce exposure to natural red and near-infrared light. Many people spend most of their day indoors under artificial lighting, behind window glass, and in front of screens, all of which create a very different light environment than regular outdoor exposure.

Natural sunlight contains a substantial amount of red and infrared light, and even cloudy outdoor conditions still provide meaningful long-wavelength exposure. That is one reason why simple habits like spending more time outside, taking walking breaks, or eating meals outdoors may be valuable additions to a healthier light routine.

Practical Ways to Improve Your Light Environment

If your goal is to increase red and near-infrared light exposure, the most accessible starting point is usually time outdoors. Regular daylight exposure may help support circadian rhythms, mood, and overall light balance, while also increasing exposure to wavelengths that are limited in many indoor settings.

When outdoor time is limited, some people choose to use red light therapy devices as a structured way to increase exposure to long-wavelength light. In the context of the 2024 study, a short session before a meal may be an interesting area for future discussion and experimentation, though people should be careful not to overgeneralize a single study into broad medical claims.

If you are considering a device, it is worth paying attention to wavelength accuracy and output data rather than relying on marketing alone. Mito Red Light publishes independent test data from an ISO/IEC 17025-accredited lab, including wavelength-resolved spectra and irradiance information for its panels.

Related reading: For a deeper look at precautions, medication-related concerns, and other situations where extra care may be appropriate, see our guide to contraindications for red light therapy.

Perspective and Caution

The idea that light influences metabolism is compelling, but it is important to keep the evidence in proportion. Red and near-infrared light may support mitochondrial and metabolic function, yet they do not replace a balanced diet, regular movement, restorative sleep, or appropriate medical care.

For readers interested in photobiomodulation, the most reasonable takeaway is not that red light is a cure-all, but that light may be one of several meaningful inputs that shape how efficiently the body produces and uses energy. As research evolves, this may become an increasingly important lens for understanding health in a modern indoor environment.

Bottom line: a healthier light environment may support healthier mitochondrial function, and healthier mitochondrial function may support better energy regulation throughout the body. That makes red and near-infrared light an area well worth paying attention to, even as the science continues to develop.