Is hiding from the sun making us sick?

Is the Sun Really the Enemy?

We’ve been told for decades that sunlight is dangerous. That it causes skin cancer. That we should avoid it, cover up, and wear SPF 50 anytime we go outside. But what if that advice—while well-intentioned—isn’t the full picture?

I've been digging into this over the past few months, and the more I read, the more I wonder if we’ve got our relationship with the sun completely upside down. Yes, burning is harmful. No one's disputing that. But chronic sunlight avoidance? That might be doing us more damage than we think.

Back in 1941, a researcher named Frank Apperly noticed that cancer death rates were significantly lower in southern U.S. states than in northern ones. He concluded that sunlight had a “preventive or retarding influence” on cancer. That was over 80 years ago.

Fast forward to the 1980s, and the Garland brothers picked up the thread. Cedric and Frank Garland found that people with higher sun exposure had lower rates of colon, breast, and even ovarian cancer. Later studies confirmed this with vitamin D levels—people with levels above 100 nmol/L had the lowest cancer risk. Researchers have kept finding the same trend. More sun, less cancer. Less sun, more cancer.

In Australia, levels below 50 nmol/L are considered mildly deficient, and anything under 30 is flat-out deficient, no matter which metric you use. The research suggests we stop seeing bone problems like subclinical osteomalacia above 75. But for long-term protection—especially from cancer—the sweet spot seems to be above 100 nmol/L. That’s where we see the lowest risk in the studies. So even if you’re technically “not deficient,” you might still be far from optimal.

But vitamin D is just part of the story.

Sunlight is a whole package—UVB helps your skin make vitamin D, yes, but UVA exposure releases nitric oxide, which helps lower blood pressure and supports immune function. As Professor Richard Weller has said, “Sunlight may have benefits for cardiovascular health independent of vitamin D.” In other words, there’s more going on here than we give credit for.

This clicked for me personally when I ran a little experiment.

For years, I wore sunglasses every time I stepped outside—just like we’re told to. But one summer I started leaving them off and paying close attention to how I felt in the sun. What I noticed was surprising: when I wore sunglasses, I would burn more easily and often didn’t even notice until it was too late. But without them, I could feel when I’d had enough sun—my skin would start to tingle or feel warm, and I’d naturally head for the shade.

Turns out this isn’t just anecdotal. There’s a feedback loop between the eyes, brain, and skin that helps regulate pigmentation and sun tolerance. If you block UV light from reaching your eyes with sunglasses (especially ones that block up to 400nm), you interrupt that loop. This has been shown in older animal studies—and while we need more human data, it makes intuitive sense. Your body is designed to feel the sun, not just on your skin but through your eyes.

This isn’t about ditching all protection or being reckless. It’s about a balanced, informed approach to sunlight. Because while melanoma is real and serious, the full story is more complicated than just UV exposure.

For example, did you know melanoma is increasing most rapidly in people who don’t spend much time in the sun? Office workers. Indoor types. It also tends to show up in areas of the body that rarely see the light of day—like the torso or underside of the arms. And when melanoma does appear on sun-exposed areas, it’s often a slower-growing, less deadly type.

Our culture of sunscreen, sunglasses, and sun avoidance has created a generation of people who are more vulnerable to damage—not less. Because if you never build up any tolerance, and then go out once or twice a year and get fried, that’s the real risk factor for melanoma. That’s what the epidemiology shows.

Dr. Max Gulhane—whose recent lecture inspired this post—pointed out that “melanoma risk is more strongly associated with intermittent, severe sunburn than with regular, moderate exposure.” He also noted that our diet plays a role. Seed oils, high in linoleic acid, have a long half-life in the body (about four years) and seem to make the skin more vulnerable to oxidative damage from UV light. As he said, “Melanoma is increasing and predominantly found in non–sun-exposed areas,” and that’s likely tied to what we eat as much as how we live.

So maybe we’ve had it backwards. Maybe we’ve been weakening our natural defenses. Avoiding the sun, slathering on SPF 50, eating inflammatory oils, sitting under artificial lights all day. And then when we do go outside, we burn. We blame the sun. But the sun hasn’t changed. We have.

To be clear: I’m not saying go lie on the beach at midday and roast. I’m not saying burn. Burning is always bad. But there’s a big difference between chronic overexposure and thoughtful, consistent, non-burning sun exposure. That’s how humans have lived for millions of years. It’s how our biology expects us to live.

So what’s the takeaway?

Get sun. Regularly. Safely. Start with short periods in the morning or late afternoon if you’re fair-skinned or just starting out. Learn your UV index—it varies by season and time of day. Build what sun aware doctors are calling a “solar callus”—a natural adaptation to sunlight, just like your skin builds a real callus with regular friction.

And maybe reconsider those wraparound UV-blocking sunglasses—especially if they’re keeping you from tuning in to how your body responds to the sun.

As Dr. Gulhane put it, “The strategy of slathering everyone in sunscreen and promoting sunlight avoidance is preventing anyone from building any resistance or natural physiological response to sunlight.” We’re staying inside all year, and then frying ourselves on the beach two days a year. That’s not a healthy relationship with the sun.

Let’s rethink it.

There’s a lot more to this story than we’ve been told. If you want to dive deeper, I highly recommend watching Dr. Max Gulhane’s talk:👉 https://www.youtube.com/watch?v=JEYxv5n1FCs