Your Healthy Sunlight Goldilocks Zone
By Alexander Germanis
Averaging a distance of 93 million miles from the earth, the star known as Sol bathes our world in life-giving light and warmth. But our planet sits in what is known as a circumstellar habitable zone, a specific orbital distance from the sun in which life is preserved. If we orbited much closer to the sun, earth’s water would vaporize, and we would die. If we orbited further out from the zone, water would freeze, plants would die, and eventually so would we.
Fortunately, we orbit in an area that’s just right for life, which is why astronomers and astrobiologists also refer to this habitable sector as the Goldilocks zone.
Sun exposure on an individual human level needs to stay in a Goldilocks zone as well. Too much sun can result in dire health consequences and too little can be equally detrimental. The right amount of sunlight, however, is not only beneficial for your physical health, but it can positively affect your mental and emotional well-being also.
Vitamins, Hormones, and Neuropeptides
The most commonly known health advantage to sunlight exposure is vitamin D production. Ultraviolet-B (UVB) radiation from the sun initiates the body’s synthesis of vitamin D, which is essential to healthy bone growth, supports the immune system, and regulates calcium and phosphorous in the body. Insufficient levels of vitamin D can result in osteoporosis, cognitive decline, and may negatively impact one’s overall health.
Those under the age of 70 should be getting at least 600 international units (IU) or 15 micrograms (mcg) of vitamin D per day. A fair skinned individual (such as I) needs at least five to 30 minutes of typical (exposed face, hands, and arms) sun exposure three times per week. More melanin in the skin acts as a barrier to the UVB radiation, so tanned and darker skinned individuals need to spend more time – two to five times longer – in the sun (while I go back to my cave).
Sunlight also affects the production of the pineal hormones serotonin and melatonin. Serotonin is produced in bright sunlight whereas melatonin is only released in darkness. When we go outside, our body produces more serotonin, which in turn results in more positive moods and a calmer mental demeanor.
Nocturnal production of melatonin occurs sooner after an earlier and prolonged day in the sun. Melatonin is responsible for better controlled circadian rhythms, more energy during the day, and better-quality sleep at night.
Some neuropeptides are also influenced by exposure to ultraviolet radiation. Some of these chemical messengers, like the calcitonin gene-related peptide and the neuropeptide substance P have been linked to treating some skin disorders and an increase in lymphocyte production, which improves the body’s immune system.
Ultraviolet radiation (UVR) exposure also triggers the release of endorphins, meaning spending time in the sun can actually improve your mood and general outlook, giving you a more, ahem, sunny disposition on life.
UV and You
As with most good things, there is such a thing as having too much. While the aforementioned times of sunlight exposure should be sought after, too much time in the sun, particularly during the hours of the day when the ultraviolet index is high (10 a.m. to 4 p.m.), can result in a sunburn or even sunstroke. Rather than risk the nausea, headaches, sunburns, and disorientation, I usually choose to cycle in the late afternoon when the UV index drops below six. An index of eight to nine means you should severely limit exposure; if it’s 10 or 11, you’re better off staying inside.
Prolonged sun exposure can result in skin cancer and a premature aging of the skin. Excessive exposure, particularly without eye protection, can also cause cataracts. Wearing sunscreen with a SPF rating of 30 or higher and sunglasses that provide 100 percent UV or UV400 protection are wise precautions.
It is also vital to stay properly hydrated when outdoors. Sun exposure, especially combined with higher winds, will dehydrate you much faster than when you’re indoors, even while doing similar activities. Always keep some water nearby and pay attention to any signs of dehydration: thirst, fatigue, dizziness, darker colored or less urine production, or confusion. Some symptoms usually attributed to children may also be signs of dehydration in adults, such as having a rapid heart rate, feeling cranky, and having a dry mouth.
Fun in the Sun
Growing up near a beach had its advantages, but my family always seemed to go for a dip when the weather was overcast, and that took a lot of the fun out of it.
Sunlight can make a great deal of outdoor activities more enjoyable. Anything water related is certainly improved by the accompaniment of solar warmth. Swimming, water skiing, tubing, water balloon fights, or playing around a sprinkler (you’re never too old for that) are all way better when you know you can dry off in the sun’s rays afterward. But use caution; water and sand both reflect the sun’s rays, effectively doubling the amount of exposure you’re getting.
Going for a walk or run, hiking in the parks, cycling, or playing any number of sports are great ways to get your daily dose of UV and exercise at the same time. Plus, the sun may help you work up a sweat a little faster, removing toxins from your body and helping you burn fat.
Working in the garden, planting a tree, or mowing the lawn are other ways to enjoy the sun, get some exercise, and get some work done at the same time.
Central Illinois is blessed with numerous parks, golf courses, and other places in which one can enjoy the sun. And remember, there’s nothing wrong with just lying down in the grass and sunbathing for a little while. The simple pleasure of listening to the birds, feeling the soft summer breeze, and soaking in the warmth of the sun can give you an emotional and mental boost.
Sunlight That’s Just Right
Just as the earth’s orbital distance from the sun varies throughout the year and the angle of the earth on its axis means certain areas of the planet certainly get more sun than others, numerous factors also come into play as to what amount of sunlight is the right amount for you.
For instance, an old friend’s ex-wife used to joke that I would get sunburned in the fog. Regrettably, she is right. Fog and clouds are poor filters of UVR, so precautions should still be taken on seemingly cloudy days, particularly for people with lighter skin.
The amount of melanin in your skin and eyes definitely plays a role in how much sunlight is right for you. “Melanin acts like an umbrella over the cell nucleus, shading and protecting the DNA from the sun’s harmful radiation,” explains Dr. Tanya Nino, dermatologist and melanoma program director at Providence St. Joseph Hospital’s Center for Cancer Prevention and Treatment. Regardless of your skin tone, limiting your time in the sun and applying sunscreen are still recommended. Anyone can get skin cancer.
Check your family medical history regarding skin cancer and your own history with sunburn. High mole counts and freckling are indicators you should take extra precautions with sun exposure.
Some medications can also make you more prone to getting sunburn. Antibiotics, oral contraceptives, some acne and diabetes medications, and over-the-counter medicines like acetaminophen or naproxen can make you more susceptible. If you’re taking medication and wish to spend a day under the rays, consult your physician and/or pharmacist.
Although your personal time with the sun can and should vary depending on personal factors, we all still need the sun to survive. Figuring out your own Goldilocks zone is something that will not only keep you safe while venturing out beneath the rays, but it will also help you better enjoy all the beauty and wellness our star has to offer.
