The sun is an indispensable agent for life on earth. It provides the daily heat and light that makes it all possible.
But the sun can also be a bother, such as during drought, sweltering heat, or when it gets in your eyes as you’re trying to drive.
Many see only the negative. There’s even a proposal to blot out the sun as a way to slow climate change. Harvard University, Bill Gates, and top scientific institutions have all prompted the U.S. government to pour $200 million into solar engineering experiments. The sun dimming plan involves spraying a chemical into the atmosphere to reflect some sunlight away from the earth.
Similarly, the trend in public health over the past few decades has been tilted toward reducing our sun exposure. The advice aims to keep us protected from the sun’s rays so we can avoid all the damage it may cause, such as sunburns, cataracts, wrinkles, age spots, and, most concerningly, cancer.
Of course, sun exposure isn’t the only factor in these ailments, and it may in fact only play a very small supporting role. While ultraviolet (UV) radiation can indirectly contribute to skin cancer, cataracts, and other diseases, excessive exposure only accounts for 0.1 percent of the total global burden of disease according to a World Health Organization report on “The Global Burden of Disease Due to Ultraviolet Radiation.”
The Other Sun Ray
The life-giving influence of the sun is enormous. Plants, for example, turn sunlight into energy through a process called photosynthesis. This solar-driven transaction also generates oxygen, enriching the air we breathe to support our own survival.
Just like photosynthesis, the sun also drives many life-giving processes in our own bodies. Most people know about vitamin D produced in our skin from the sun’s ultraviolet rays, but fewer know that the sun’s infrared and near-infrared light also has a profound effect.
In a study published in Metabolic Brain Disease using mice, researchers found that “low-intensity NIR [near-infrared] may attenuate hypoxia/ischemia-induced mitochondrial dysfunction in neurons.” In other words, this light can help alleviate damage caused to the mitochondria in neurons, our brain cells. Mitochondria are the powerhouses of our cells, creating the energy for all cellular activity.
This same light is also known to have a neuroprotective effect on Parkinson’s disease (PD), a finding that has prompted a therapy called “photobiomodulation.”
While a study published in Frontiers in Aging Neuroscience in 2020 states that “our understanding of the neuroprotective mechanism of PBM [photobiomodulation] remains far from complete,” it also states that “PBM represents a potential novel therapy for PD.”
Near-infrared (NIr) has been found to be a widely effective treatment, according to a 2015 study published in Frontiers in Neuroscience.
“The fact that NIr therapy has been reported to be effective in so many different models of disease and in a range of neural systems suggests that it is not a targeted therapy, but instead, acts to mitigate ubiquitous processes relating to cell damage and death,” reads the study, which was conducted by an international group of researchers.
While candles and fire do emit infrared, the sun is the major source people have relied on for millennia.
A Healthy Relationship With Sunlight
But even before people understood all the science behind the sun’s virtues, they understood that it contained immense power.
Some ancient cultures viewed the sun as the ultimate embodiment of the masculine principle (yang), and others even worshiped it. Ancient doctors considered the sun to be the premiere healer. For generations, a common prescription for a variety of ailments consisted of exposing patients to ample doses of fresh air and sunshine, and common experience and modern science both back these up.
Today, however, we rarely hear about the sun’s virtues. Instead, we mostly hear about the damage it can do to our health.
The question becomes, are the benefits worth the risks? Often the answer comes down to how responsible you are about UV exposure.
Samantha Dean is a living example. Dean is a metastatic melanoma survivor who said she’s at high risk of its return. She’s fairly certain that her diagnosis is linked to frequent tanning bed use as a teenager.
Yet despite Dean’s elevated risk, she still enjoys being outdoors, and her dermatologist encourages it.
“I still participate in daytime races, go swimming, and walk my dogs. I enjoy sipping on my morning coffee poolside. These are things that benefit my mental health,” she said. “Of course, I don’t want a new melanoma spot to pop up. But I also don’t want to hide inside with my blinds closed all day.”
Dean said her dermatologist explained that too little sun could harm her health in other ways. He shared a story about a patient who, after a skin cancer diagnosis, got rickets because she never got any sunshine. Rickets is a degenerative disease characterized by the weakening, deterioration, and deformation of muscles and bones.
“It’s about finding the right balance for each individual,” Dean said. “I go outside and enjoy what the universe has provided us. Natural light is one of the best mood boosters, so I refuse to hide away indoors fearing cancer for the rest of my life. For me, the benefits outweigh the risks.”
Necessary Sun Exposure
Rickets is rare these days, but in the early 20th century, the disease was rampant among children living in the cities of the northern United States.
Doctors identified a lack of sunshine as the cause because children in the country—who were constantly outside—didn’t get the disease. Urban children, in contrast, grew up in factories rather than farms, and even when they got a glimpse of the outdoors, the significant urban pollution of the era dramatically dimmed the available sunshine.
Regular sun exposure has several health benefits, but the most studied is that unusual hormone called vitamin D. The rise in rickets prompted its discovery, but new insights about vitamin D emerge all the time. Sun exposure on our skin is what stimulates our cells to generate vitamin D, which has been found to strengthen our muscles, bones, immune system, mood, and so much more.
Researchers have found that adequate vitamin D levels can protect against auto-immune diseases, such as multiple sclerosis, as well as chronic illnesses, such as bone metabolic disorders, tumors, cardiovascular diseases, and diabetes. Scientists continue to discover new functions for vitamin D. For example, a recent meta-analysis has confirmed that vitamin D defends against COVID-19.
Vitamin D is unique because, unlike most other vitamins, our body produces vitamin D on its own with exposure to UV rays. Similarly, while most other vitamins can be consumed through a variety of food sources, few foods contain significant amounts of vitamin D.
It’s hard to dispute our body’s need for vitamin D, but some dermatologists urge patients to avoid the harmful effects of sun exposure and instead obtain their vitamin D through oral supplementation, but such advice overlooks the many other benefits of sun exposure.
For modern urban dwellers who still see little sunshine, supplementation is a reliable way to boost vitamin D levels. It’s how the scourge of rickets was eradicated, after all. In the 1940s and 1950s, public health experts called to fortify the food supply with a dietary form of vitamin D.
But supplements alone can’t replace all the sun’s virtues. Elisa Regulksi, a Certified Sleep Science Coach said sun exposure has an important relationship with sleep. She explained that sunlight exposure regulates our sleep-wake cycles via a chemical called melatonin—a hormone that makes us feel sleepy.
“When the sun rises in the morning and we are exposed to sunlight, this signals to our bodies that it’s time to stop producing melatonin and wake up. So when this cycle of natural light gets disrupted, perhaps by staying inside in a poorly lit room or getting too much light exposure at night from a screen, our sleep is negatively impacted,” Regulksi said.
A Sunnier Disposition
Dr. Enrizza P. Factor, a researcher and clinical dermatologist, said sunlight also helps boost a chemical in our brains called serotonin. This neurotransmitter is often associated with alleviating depression and encouraging a brighter mood. Adequate levels of serotonin can give you more energy and help keep you calm, positive, and focused.
Factor said that without enough sun exposure, your serotonin levels can dip, leading to a higher risk of major depression and seasonal patterns of sadness and melancholy during the winter months, when available sunlight is hard to come by.
“Sunlight is essential for human health and well-being,” Factor said. “Phototherapy is still used today to treat conditions such as eczema, psoriasis, jaundice, mood and sleep disorders, and some cancers. The healing power of the sun is a powerful reminder that the sun plays an important role in human health and should not be avoided.”
According to board-certified dermatologist Dr. Patricia Gaile Espinosa, in addition to boosting our levels of vitamin D, sun exposure also minimizes the risk of developing diseases such as metabolic syndrome, Alzheimer’s disease, and rheumatoid arthritis.
But Espinosa stresses that, for all the sun’s benefits, it’s important to understand the extent of its harms.
“People do not need to sunbathe for long periods to get this benefit. Too much exposure at peak hours at the hottest time of day may cause sunburn or photodamage. The damage on the skin leads to skin aging and skin cancer,” Espinosa said. “Limiting the time of exposure can minimize skin damage and dehydration as well, while still producing vitamin D.”
Coping With a Harsher Sun
Why did doctors in the past celebrate the sun, while many physicians today urge caution? Perhaps it’s because people used to be able to soak up more sun with fewer problems. Chemical pollution over the past several decades has led to a 5 percent reduction in the ozone layer—an atmospheric shield that serves to screen out much of the UV rays that the sun beams down.
Although researchers report that the ozone hole has been shrinking in recent years, according to Dr. Harold Hong, a board-certified psychiatrist and medical director of the New Waters Recovery Center in North Carolina, an hour or two in the sun exposes us to more UV rays than our ancestors experienced.
“That’s not to say that the sun can’t benefit our health in moderation. Like anything, too much of a good thing can be bad for us. Get enough sun to improve your mood and get some vitamin D, but don’t stay out in the sun for too long and put yourself at risk for skin cancer.”
According to NASA, the northern latitudes, including North America, have seen about a 5 percent increase in UV levels, so the change isn’t dramatic.
Sunscreen Controversies
Liberal use of sunscreen is the prevailing wisdom in skin care, but the recommendation isn’t without controversy. Some doctors believe that sunscreen causes more harm than good. Not only does sunscreen use prevent our skin from generating nearly as much vitamin D as bare skin, but there’s also some evidence that suggests that some common chemicals in sunscreens can disrupt our hormonal levels. Other evidence even suggests that these products do more to promote cancer than to protect us from it.
You can find a discussion about the downsides of sunscreen in a recent Wise Traditions podcast featuring Dr. Elizabeth Plourde. a clinical laboratory scientist and the author of “Sunscreens Biohazard 2: Proof of Toxicity Keeps Piling Up.”
According to Plourde, the body naturally protects itself from sun damage, provided that it has enough antioxidants.
“Our bodies are designed so that the antioxidants come up in the skin. When solar radiation hits the skin, the antioxidants come up and protect the skin from any damage. When you start turning red and burning, you’re out of antioxidants. It’s that simple. We just need to replace the antioxidant,” Plourde said.
According to Plourde, eating a diet rich in antioxidants can help protect us from sun damage. But some skin types naturally have higher levels of antioxidants.
Healthy Sun Exposure
The sun shines from sunrise to sunset, but UV rays are strongest from about 10 a.m. to 4 p.m. This daytime segment of particularly intense sunlight allows us to soak up the most vitamin D in the shortest amount of time.
About 5 to 15 minutes of midday sun three times a week is all it takes for fair-skinned people. People with darker skin will require longer periods of sun exposure, as lighter skin produces about six times more vitamin D than darker skin. Darker skin is also better protected from UV thanks to increased melanin.
Melanin is a pigment that gives skin its color. Dark-skinned people have a lot of melanin and, as a result, can often spend more time in direct sunlight without consequence. But melanin doesn’t just make skin dark, this pigment is also a powerful antioxidant that’s shown to have anti-cancer properties.
Locale also plays a big role. For example, folks living in Florida have a lot more opportunity to catch some vitamin-D-rich rays than Alaskan residents.
Dr. Brian Kaplan has lived at both extremes of sun exposure. He’s currently a medical doctor in notoriously cloudy London, but he was born in exceptionally sunny Africa, where he said malignant melanomas aren’t an uncommon diagnosis.
“Yes, sunlight allows us to manufacture our own vitamin D. However, a half hour of your nose in the sun a day will probably be enough,” Kaplan said. “Dark-skinned people in cold countries need to take oral vitamin D more than others, but a recent survey showed that about 50 percent of people in England are low in vitamin D.”
Kaplan said people with very fair skin are more vulnerable to sun damage. He said they still need to get some sun every day, but they’re genetically suited to locales that receive less sunlight.
“So if you are pale, you benefit from a little sun, but too much can hurt you both in the short and long term,” Kaplan said.
Nobody wants a sunburn, but many seek a tan—a darkening of the skin due to sun exposure. Some insist that a tan can actually protect you from some of the negative aspects of exposure. The idea is that a tan generates more skin-protecting melanin.
But dermatologist Dr. Cynthia Bailey said not all tans are created equal. In a blog post examining the topic of tanning, Bailey said an “immediate tan”—a skin-darkening process that occurs over the course of an afternoon—doesn’t generate more melanin. It merely redistributes the pigment that was already in your skin.
However, a tan that slowly comes on over the course of an entire summer can generate some sun protection. But it comes at a price.
“The tan occurs because your skin actually makes more melanin pigment granules and spreads them out in the living layer of your skin. This means that it does give you a small amount of sun protection, but at the expense of DNA damage. Remember, tans are temporary because these melanin granules grow up and out of your skin as your cells shed,” Bailey wrote.
According to Kaplan, the only benefit of a tan is the aesthetic it creates.
“It’s always amazed me that white people in cooler countries want to tan and dark people in hot countries often use skin lighteners. Overexposure to skin and skin-lightening products can be dangerous if overdone,” he said.
