High summer has returned to the UK, and with it, the usual warnings about the dangers of sunlight.
After years of such advice, most people assume the science is well established.
But the opposite is true: those who spend more time in the sun tend to be healthier—a lot healthier.
Rowan Jacobsen, author of In Defense of Sunlight, began researching the subject nine years ago after stumbling upon some studies.
He now summarizes everything we know in his new book, which contains good news: we don't have to fear the sun nearly as much as we thought.
In fact, most of us could benefit from a bit more exposure.
The Science Behind Sunlight's Benefits
Sunlight hitting skin produces vitamin D, but it also produces dozens of different beneficial molecules.
These molecules lower blood pressure, reduce inflammation, increase energy and alertness, improve sleep, and release natural endorphins in the brain.
The result? Less disease and better longevity.
In 2024, scientists published a study using light-sensing wrist monitors on more than 88,000 volunteers in the UK Biobank dataset.
They tracked light exposure day and night, then followed volunteers for years.
Those who received the most daylight were 34% less likely to die from any cause than those with less light exposure.
Even after accounting for exercise, diet, and other factors, the light-getters were still 17% less likely to die.
Balancing Skin Cancer Risks
But what about skin cancer?
People getting lots of sun are more likely to get skin cancer, but it is less deadly than most think.
Skin cancer is very common, but the vast majority of cases are minor, requiring simple removal. Melanoma, the much more dangerous kind, is fairly rare.
Overall, about 3,500 people die of skin cancer in the UK each year—just 1% of the 350,000 deaths from cancer and cardiovascular disease.
Skin cancer shouldn't be downplayed, but if encouraging people to hide from the sun raises their risk of more impactful diseases, it's time for a new conversation.
The benefits are so much greater because it doesn't take much sun to get them.
Nobody needs a huge amount; sunburns are clearly detrimental and associated with higher rates of melanoma.
The dangers come from getting almost no sunlight—and that's exactly the amount more people are getting.
Why don't we hear about this more often?
Jacobsen chalks it up to anchoring bias: people cling to the first information they hear, even if better information comes later.
Institutions are even more susceptible.
The powers that be spent so much time convincing people to get out of the sun that they are loth to admit the reality is more complicated.
So what should we do? The answer depends on who you are, where you are, and what time of year it is.
Original recommendations to shun the sun came from Australia—one of the sunniest places on Earth, with a predominantly fair-skinned population.
There, those recommendations made sense, though they have resulted in a surprisingly high level of vitamin D deficiency.
In a low-light environment like the UK, different recommendations are in order. On bright summer days, limit your exposure, and sunscreen can help.
Although it impedes vitamin D production by blocking ultraviolet light, it still allows other wavelengths to work their magic, improving sleep, circadian alignment, and reducing inflammation and anxiety.
By protecting against skin cancer, it gets more people outside.
Most important is to keep in mind who you are.
Fair-skinned individuals with blond or reddish hair are much more susceptible to skin cancer; they really need to be cautious.
If you have more melanin, your risk goes down substantially.
If you have a lot of melanin, you are unlikely to develop skin cancer from UK-level sun and stand to benefit most of all.
For now, please enjoy the beautiful light of the northern summer. It's brief—and truly not to be missed.
