Sun Exposure · Introductory essay
Melanin and My Relationship With the Sun
Why melanin changed the way I think about sunlight—and why the question reaches deeper than skin color.
I believe we’ve underestimated melanin. We notice the color it gives skin, but its significance reaches into the body’s inner workings. That is why it belongs at the center of how I think about sunlight.
Jack Kruse’s conversation with Max Gulhane on Regenerative Health helped bring that into focus for me. His account connected light, pigment, and the body’s energy systems in a way that made me look at the subject differently. The question became larger: what is happening when sunlight meets my skin, and how does that relate to what is happening inside?
Skin as an interface with the sun
When I call my skin a “solar panel,” I’m talking about sunlight and cellular energy. Mitochondria help cells produce ATP, a molecule they use to power their work. The possibility of light interacting with that process is the crux of the analogy.
Researchers have measured changes in mitochondrial activity and ATP under selected laboratory light conditions. That gives the energy question a scientific starting point. It does not establish a complete pathway in which skin melanin captures sunlight and supplies that energy directly to mitochondria in a person. I examine that distinction in Skin as a Solar Panel.
For me, melanin is our interface with the sun. That is how I frame its importance. Understanding the particular jobs it performs requires looking at the pigment, the tissue, and the kind of light involved.
Deeper than skin deep
Consider the substantia nigra, a region of the midbrain whose name means “black substance.” Neuromelanin inside many of its dopamine-producing nerve cells contributes to that dark appearance. Pigment is present deep inside the brain, far beyond the skin we can see. See the National Library of Medicine anatomy reference.
Melanin is pigment; a melanocyte is a cell that makes skin pigment. A pigment-containing neuron in the substantia nigra is a nerve cell, with a different job. Those distinctions matter when we talk about pigment deep inside the body or ask whether anything moves between tissues.
In a 2008 laboratory study, Luigi Zecca and colleagues examined neuromelanin isolated from human substantia nigra. It bound iron and limited reactions that can generate damaging molecules under the conditions tested. Binding iron changes how available it is for those reactions, giving the pigment’s chemistry a concrete significance inside the cell. The researchers also described conditions in which breakdown of the pigment–iron complex can release reactive iron. Both findings matter; “more pigment is always better” would miss that dependence on the setting. Zecca et al. (2008): neuromelanin and iron chemistry.
Another study of human brain tissue identified melanic pigments in regions including the putamen, cortex, and cerebellum. The researchers examined their chemistry and ability to bind metals. These pigments share some structural features with skin melanin, but their composition and biological context differ. The substantia nigra is one example of a wider subject. Zecca et al. (2008): pigments in human brain tissue.
That is what makes internal melanin so compelling to me: pigment can participate in chemistry that matters to the cells containing it. Finding pigment in the brain, however, does not by itself show that sunlight activates it there.
Kruse goes further. Around 1:31–1:34 in his conversation with Max Gulhane, he connects a patient’s changing skin pigmentation with a proposed redistribution from internal sites toward the skin. That is his interpretation of the case. The pigment studies above do not demonstrate such movement, and a report of skin changing color does not by itself establish where its pigment or pigment-producing cells came from.
Be specific about “activation”
Sunlight can set biological processes in motion. In a 2007 study, Rutao Cui and colleagues showed a pathway connecting UV exposure with skin pigmentation. A protein called POMC is broken into smaller chemical messengers, including one that stimulates melanin production. Cui et al. (2007): UV exposure and skin pigmentation.
Producing more pigment is one process. What pigment does after it is present is another. And what happens in skin does not automatically tell us what happens in a nerve cell deep in the brain. Keeping those questions separate helps me understand the larger picture without losing the connections that first caught my attention.
UV exposure can damage DNA, and pigmentation does not remove that risk. Curiosity about melanin belongs alongside care for the skin. Lan et al. (2023): melanin caps in skin cells.
Why this matters to my relationship with sunlight
The discovery that stays with me is that pigment belongs in this conversation far beyond the skin we can see. Inside the brain, its chemistry can matter to the cells containing it. That gives my curiosity a concrete foundation.
From there, I want to understand the energy question that first caught my attention: when sunlight meets the body, what reaches the tissue, what absorbs it, and what changes in response? That is the next part of the story.
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