Every thought, heartbeat, and breath depends on a steady flow of cellular energy. Deep inside each of your cells are thousands of tiny engines called mitochondria, organelles that transform nutrients and oxygen into usable energy in the form of ATP (adenosine triphosphate).
We often think of energy as something we get from food, but light, specifically certain wavelengths of visible light also plays a surprisingly direct role in this process. The emerging field of photobiomodulation explores how photons can influence mitochondrial activity, revealing an elegant connection between energy from the environment and energy inside our cells.
Mitochondria are sometimes called the “powerhouses” of the cell, but a better description might be energy translators. They take electrons from the food we eat and, through a series of reactions called the Mitochondria are sometimes called the “powerhouses” of the cell, but a better description might be energy translators. They take electrons from the food we eat and, through a series of reactions called the electron transport chain, use them to generate ATP., use them to generate ATP.
The final enzyme in this chain, cytochrome c oxidase (CCO), plays a pivotal role. It’s also photosensitive. Research has shown that red and near-infrared wavelengths (typically between 630–850 nanometers) can be absorbed by CCO, changing its structure and activity.
When this happens, several biochemical effects can occur:
In other words, light can fine-tune the same processes that keep cells alive and functioning.
ATP fuels every major function in the body from muscle contraction and hormone synthesis to nerve transmission and cellular repair. When mitochondria work optimally, ATP production is stable and efficient. When they falter, the ripple effect can be dramatic in many organs and systems in the body. Energy wanes, recovery slows, and inflammation may rise.
By influencing how mitochondria handle oxygen and electrons, medical laser light acts as a subtle environmental signal that helps recalibrate the balance between energy output and oxidative stability.
Not all light behaves the same. Different wavelengths penetrate to different depths and interact with unique cell types, tissues and biological targets.
| Wavelength Range (nm) | Colour | Primary Cellular Interaction |
|---|---|---|
| 630–660 | Red | Stimulates cytochrome c oxidase → ATP production |
| 810–850 | Near-infrared | Deeper penetration, affects mitochondrial membranes and intercellular signaling |
| 520–540 | Green | May influence redox activity and electron transport intermediates |
Understanding this specificity helps explain why photobiology focuses less on “light exposure” in general and more on the right type of medical laser light for the right molecular target.
When photons interact with mitochondria, the effects extend beyond energy metabolism. Changes in ATP, reactive oxygen species, and nitric oxide can influence how cells communicate with one another, guiding processes like growth, repair, and immune coordination.
This broader signaling network shows that mitochondria are not just engines of metabolism, but also sensors, constantly integrating cues from the environment to decide how much energy to produce and where to send it.
In our modern world, we often separate biology from physics, food for fuel, light for sight. Yet at the cellular level, these systems are deeply intertwined. The study of light and mitochondria reminds us that human energy is not only biochemical but also biophysical, influenced by the subtle conversation between our cells and the signals that influence them.
Dr. Ryan Best is a naturopathic doctor with a focus on complex, chronic illness — including MCAS, histamine intolerance, environmental sensitivities, and integrative cancer care. Drawing on advanced testing and functional medicine frameworks, he helps patients uncover the root causes of their symptoms and build personalized treatment plans that actually work. Dr. Best is based in Calgary and sees patients across Canada through virtual care.
