These states get way less sun, but have way more skin cancer....

And your first thought might be: Those who live in Florida & (especially) Hawaii have so much more melanin, but the data I want to show you is based primarily on non hispanic - caucasian individuals......and even the fair skinned people in Hawaii & Florida have lower melanoma rates than those in northern states with far less sun.

I posted about this today on Instagram (click here to read), and there is a lot of reductionistic thinking in the comments - blaming one thing such as: sunscreen, sunglasses or seed oils (click here to read my deep dive article on why I don't think that's entirely the case).

So if this topic interests you - keep reading!

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If sun is the primary cause of melanoma, why are people in cold, low-UV states getting it more often?

Let's talk about why we have to look beyond ONE primary cause of skin cancer, and learn how to think critically again.

Sunlight isn’t inherently carcinogenic, and it is an essential biological signal that sustains life.

However - when your body loses the ability to process light properly, even small doses can become damaging.

This is where a multi-faceted approach that includes: circadian biology, melanin, and mitochondrial health come into the conversation.​​

Directly from the CDC Cancer Registry

Minnesota - with long winters, short days, and low UV - has more melanoma than Hawaii or Florida.

So the question really is: if the sun is the primary cause of melanoma, why are people in cold, low-UV states getting it more often?

Minnesota experiences cold, long, dark winters with significantly fewer daylight hours. As a result, residents are often deprived of full-spectrum natural light, especially early morning light, which is critical for entraining the body’s master clock in the brain (the suprachiasmatic nucleus, or SCN).

To make up for the lack of natural light, most people rely heavily on artificial lighting - especially blue-rich LED light indoors, often from screens - which is missing red, infrared & UV - and does not deliver the same biological signaling as natural sunlight. This artificial environment leads to chronic circadian disruption.

Why does that matter for skin cancer?

Because circadian rhythms don’t just regulate your sleep- they also highly regulate your genes.

A landmark study published in Cell (Zhang et al., 2014) found that over 50% of all protein-coding genes in mammals are under circadian control. This includes genes involved in:

• DNA repair
• Cell cycle regulation
• Tumor suppression
• Immune surveillance
• Antioxidant defense mechanisms

When your circadian rhythms are off - due to a lack of morning light, irregular sleep-wake cycles, or nighttime blue light exposure - these critical gene pathways fall out of sync.

In the context of melanoma, that means your body might be:

• Less efficient at repairing from UV exposure
• More likely to allow damaged cells to survive and proliferate
• Less able to mount appropriate immune responses to mutated cells
• More inflamed, oxidative, and metabolically fragile overall

In simple terms, your body’s ability to respond to oxidative stress, detect and eliminate damaged cells, and repair mutations depends on light-timed gene expression.

In northern environments like Minnesota, this mismatch between external light cycles and internal biological clocks creates the perfect storm: low vitamin D, low melatonin, poor redox status - and impaired gene regulation.

Citation: Zhang R, Lahens NF, Ballance HI, Hughes ME, Hogenesch JB. A circadian gene expression atlas in mammals.” Cell. 2014 Dec 4;159(5):1140-1152.

In Minnesota, people compensate for darkness with artificial lighting - often cool, blue-rich LEDs indoors and from screens. But blue light has powerful biological effects that go far beyond eye strain.

Blue light at night suppresses pineal melatonin, a hormone most people associate with sleep, but which is also a potent antioxidant and oncostatic agent (meaning it helps prevent cancer).

Melatonin protects your skin by:

• Scavenging reactive oxygen species (ROS)
• Supporting mitochondrial redox balance
• Enhancing DNA repair
• Inhibiting abnormal cell proliferation

When blue light suppresses melatonin production after sunset, the skin becomes more vulnerable to oxidative and UV damage - even if UV exposure is limited.

Citation: “Melatonin exerts oncostatic actions via modulation of oxidative stress, mitochondrial function, and immune responses.” - Hardeland R, Clin Dermatol, 2016

Beyond night-time melatonin:

In Hawaii or Florida, people are more likely to receive strong morning light, near-infrared throughout the day (which creates subcellular melatonin), and less artificial light exposure at night due to outdoor lifestyles - all of which help preserve circadian rhythm, melatonin production, and skin resilience.

Citation: Hardeland R. “Melatonin and skin: regulation of circadian rhythms, redox status and skin aging.” Clin Dermatol. 2016.

Most people focus on UV when they think of sun exposure. But nature isn't stupid, and near-infrared (NIR) light - which makes up over 40% of sunlight- is present any time the sun is up, even on cloudy days & while you are in the shade if there are green plants to reflect off of!

Near infrared light penetrates deep into the skin and interacts with cytochrome c oxidase in your mitochondria, enhancing cellular water production - ATP production and improving overall cellular health.

This process actually preconditions your cells to handle oxidative stress, including UV exposure (and is one reason why red light therapy can be so helpful)

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In simple terms: NIR strengthens your defenses before UV even hits.

NIR stimulates the production of subcellular melatonin- a powerful antioxidant made inside your mitochondria. Unlike pineal melatonin, this version doesn’t depend on darkness or sleep. It works locally to neutralize free radicals, reduce lipid peroxidation, and protect mitochondrial DNA.

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Citation: Wunsch A, Matuschka K. “A controlled trial to determine the efficacy of red and near-infrared light treatment on UV-induced skin damage.” Photomed Laser Surg. 2014.

Tan DX et al. “Mitochondria and the melatonin miracle.” J Pineal Res. 2016.

In tropical regions like Hawaii and Florida, people receive regular, high-dose NIR exposure by default of longer days and more sunlight.

But in places like Minnesota, especially indoors behind glass (which blocks NIR), this protective signal is largely missing.

It’s not just the amount of sun that matters - it’s how and when your body is exposed to it - Let me explain:

In northern states like Minnesota, people often go weeks or months without meaningful sun exposure (and spend most of their time devoid of any red & infrared), especially during fall and winter. When spring or vacation rolls around, they suddenly spend hours outside - without melanin buildup, redox preparation, or mitochondrial adaptation.

This intermittent, unbuffered UV exposure is far more damaging than daily, gradual exposure. The skin is caught off guard- lacking melanin and subcellular melatonin- and is more likely to burn, inflame, and accumulate DNA damage.

In contrast, tropical and subtropical regions like Hawaii and Florida offer regular, consistent sunlight year-round. That daily exposure allows the skin to gradually increase melanin, reinforce redox defenses, and adapt to the light environment.

This difference in pattern of exposure is a very very important factor that is often overlooked entirely.

A well-known study of Navy personnel found that those with chronic occupational sunlight exposure had lower melanoma risk compared to those with intermittent recreational exposure, despite receiving more total UV. This strongly suggests that adaptation, not avoidance, is the safer path.

Citation: Garland FC et al. “Occupational sunlight exposure and melanoma in the U.S. Navy.” Arch Environ Health. 1990.

The CDC’s melanoma incidence data is drawn largely from non-Hispanic white populations, who account for the vast majority of melanoma cases in the U.S. - especially in northern states like Minnesota, Vermont, and New Hampshire, where over 85–90% of the population is fair-skinned.

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​This is critical context:

Melanoma is more common in fair-skinned individuals living in low-UV environments than in fair-skinned individuals living in high-UV states like Hawaii and Florida.

While Hawaii and Florida are more racially diverse, they still include large fair-skinned populations - yet their melanoma rates remain significantly lower.

This suggests that melanin alone cannot account for regional differences in skin cancer risk.

Instead, it points to the role of light adaptation, circadian regulation, and photobiological resilience as key protective factors - even among those with lower baseline melanin.

Source: CDC United States Cancer Statisticshttps://gis.cdc.gov/Cancer/USCS/DataViz.html​

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Ready to learn how to adapt to sunlight the right way?

Free: Download MyCircadianApp & watch all of the free in app videos from the home screen! You can also use code SARAHK for a free trial of the premium version.

I also teach safe sun exposure inside Sunwise - a course on safe sun exposure, melanin activation, mitochondrial repair, summer nutrition, sunscreen, sunglasses and rebuilding your skin’s natural defenses.​

In Quantum Nutrition you get light and nutrition strategies for each season (yes even the cold dark winter) - special protocols for weight loss, thyroid, autoimmune, perimenopause & fertility.

I hope you found this article helpful & will consider forwarding to a friend or family member.