Most public health messages of the past century have focused on the
hazards of too much sun exposure. Long wave ultraviolet radiation (95–97% of
the UVR that reaches Earth’s surface) penetrates deeply into the skin, where it
can contribute to skin cancer indirectly via generation of DNA-damaging
molecules such as hydroxyl and oxygen radicals. Sunburn is caused by too much
UVB radiation; this form also leads to direct DNA damage and promotes various
skin cancers. Both forms can damage collagen fibers, destroy vitamin A in skin,
accelerate aging of the skin, and increase the risk of skin cancers. Excessive
sun exposure can also cause cataracts and diseases aggravated by UVR-induced
immunosuppression such as reactivation of some latent viruses.
hazards of too much sun exposure. Long wave ultraviolet radiation (95–97% of
the UVR that reaches Earth’s surface) penetrates deeply into the skin, where it
can contribute to skin cancer indirectly via generation of DNA-damaging
molecules such as hydroxyl and oxygen radicals. Sunburn is caused by too much
UVB radiation; this form also leads to direct DNA damage and promotes various
skin cancers. Both forms can damage collagen fibers, destroy vitamin A in skin,
accelerate aging of the skin, and increase the risk of skin cancers. Excessive
sun exposure can also cause cataracts and diseases aggravated by UVR-induced
immunosuppression such as reactivation of some latent viruses.
Positive Effects of the Sun
Vitamin D production
The best-known benefit of sunlight is its
ability to boost the body’s vitamin D supply; most cases of vitamin D
deficiency are due to lack of outdoor sun exposure. At least 1,000 different
genes governing virtually every tissue in the body are now thought to be
regulated by 1,25-dihydroxyvitamin D3 (1,25[OH]D), the active form of the
vitamin, including several involved in calcium metabolism and neuromuscular and
immune system functioning.
ability to boost the body’s vitamin D supply; most cases of vitamin D
deficiency are due to lack of outdoor sun exposure. At least 1,000 different
genes governing virtually every tissue in the body are now thought to be
regulated by 1,25-dihydroxyvitamin D3 (1,25[OH]D), the active form of the
vitamin, including several involved in calcium metabolism and neuromuscular and
immune system functioning.
Although most of the health-promoting
benefits of sun exposure are thought to occur through vitamin D photosynthesis,
there may be other health benefits that have gone largely overlooked in the
debate over how much sun is needed for good health [see “Other Sun-Dependent
Pathways,” p. A165]. As for what constitutes “excessive” UVR exposure, there is
no one-size-fits-all answer, says Lucas: “‘Excessive’ really means
inappropriately high for your skin type under a particular level of ambient
UVR.”
benefits of sun exposure are thought to occur through vitamin D photosynthesis,
there may be other health benefits that have gone largely overlooked in the
debate over how much sun is needed for good health [see “Other Sun-Dependent
Pathways,” p. A165]. As for what constitutes “excessive” UVR exposure, there is
no one-size-fits-all answer, says Lucas: “‘Excessive’ really means
inappropriately high for your skin type under a particular level of ambient
UVR.”
Enhances Your Mood
Dr. Carey Bligard, MD, UnityPoint Health says
there are many benefits from sunlight, including that it is a free mood
enhancer. Being in the sun can make people feel better and have more energy.
Sunlight increases the levels of serotonin in the brain, which is associated
with improved mood. Not surprisingly, serotonin levels are highest in the
summer.
there are many benefits from sunlight, including that it is a free mood
enhancer. Being in the sun can make people feel better and have more energy.
Sunlight increases the levels of serotonin in the brain, which is associated
with improved mood. Not surprisingly, serotonin levels are highest in the
summer.
Treats Seasonal Depression
(commonly referred to as Seasonal Affective Disorder)
In certain people, the lack of sunlight in
the winter seems to trigger depression. Symptoms include bad moods, difficulty
making and keeping friends, overeating, tiredness and sleeping too much.
Seasonal depression, formerly known as Seasonal Affective Disorder,
is rare in the warmer months.
the winter seems to trigger depression. Symptoms include bad moods, difficulty
making and keeping friends, overeating, tiredness and sleeping too much.
Seasonal depression, formerly known as Seasonal Affective Disorder,
is rare in the warmer months.
Relieves Stress
Everyone experiences stress for various
factors, such as family, work and health issues. Dr. Bligard says stress can be
relieved in a variety of ways, including exercise, having relaxing hobbies,
walking the dog or by getting out in the fresh air for a little sun exposure.
factors, such as family, work and health issues. Dr. Bligard says stress can be
relieved in a variety of ways, including exercise, having relaxing hobbies,
walking the dog or by getting out in the fresh air for a little sun exposure.
Improves Sleep
Sunlight exposure impacts how much melatonin
your brain produces, which is what tells your brain when it is time to sleep.
When it gets dark, you start producing melatonin so you are ready to sleep in
about two hours. With more sunlight in the summer, you are likely to feel more
awake. Dr. Bligard points out that modern technology has allowed us to change
our light exposure artificially with lights, TV screens and computer screens
(including tablets and cell phones). Consequently, the incidence of insomnia is
much higher now than it was before these devices were invented.
your brain produces, which is what tells your brain when it is time to sleep.
When it gets dark, you start producing melatonin so you are ready to sleep in
about two hours. With more sunlight in the summer, you are likely to feel more
awake. Dr. Bligard points out that modern technology has allowed us to change
our light exposure artificially with lights, TV screens and computer screens
(including tablets and cell phones). Consequently, the incidence of insomnia is
much higher now than it was before these devices were invented.
Protection from the
Sun
Much of the damage to our skin caused by
sun exposure can be prevented. Sunscreen must be applied 20 minutes before
going out in the sun and should be reapplied after two hours in the sun and
after swimming or heavy sweating. You can also protect yourself with UV
filtering sunglasses, long sleeves or a brimmed hat. If you are going to be
outside for long periods, sit under a cover of a building, an umbrella or a
tree that has dense shade underneath.
sun exposure can be prevented. Sunscreen must be applied 20 minutes before
going out in the sun and should be reapplied after two hours in the sun and
after swimming or heavy sweating. You can also protect yourself with UV
filtering sunglasses, long sleeves or a brimmed hat. If you are going to be
outside for long periods, sit under a cover of a building, an umbrella or a
tree that has dense shade underneath.