In the last post we talked about some of the benefits of getting outside in nature every day (missed it? click here.), getting in a dose of greenery, trees, plants, and dirt does wonders for our physiological and our mental health.
Who doesn’t like nature? Today we’re going to talk about another benefit of getting outside every day: sun exposure.
Usually when we talk about sun exposure we talk about the danger of getting skin cancer associated with sun exposure, especially getting a sunburn, and the importance wearing SPF and blocking the suns harmful rays. But the sun’s rays aren’t all bad. Quite the opposite, actually, unprotected sun exposure is quite important for our mental and physical health.
Benefits of unprotected (gasp!) sun exposure
Sun exposure is linked with all sorts of health benefits, from better sleep to better moods to better physiological functioning to disease prevention.
The biggie benefit, and one most of us are familiar with, is vitamin D synthesis. When vitamin D is synthesized through our skin from sunlight, it is a powerful health booster and health protector.
Most of our cells and organs have vitamin D receptors, because of this the vitamin D production that occurs as a result of sun exposure (and not just food or supplement intake) supports a number of biological pathways, playing a role in everything from metabolic functions to neuromuscular transmissions to bone mineralization.
Sun exposure and flourishing health
Adequate vitamin D levels are also important to fend of disease and stay healthy. Vitamin D deficiency has been associated with a number of chronic diseases, including multiple sclerosis and other auto-immune diseases, rickets and other bone disorders, metabolic dysfunction and type 2 diabetes, heart disease, some cancers, and some mental disorders, including seasonal affective disorder (SAD), depression, and schizophrenia.
Cancer Protection
While sun exposure may lead to increased risk of some skin cancers, the more sun exposure we have is also associated with lower incidences of other forms of cancer throughout the lifespan, including breast and prostate cancer and even including some forms of skin cancer.
It appears that sun exposure in adolescence and early adulthood is more protective against cancers than harmful (meaning it protects against more cancers than it puts us at risk for) and continued exposure into adulthood is protective as well.
Enhanced Immune Function
Sun exposure is also linked with better immune function, historically associated with fewer auto-immune diseases like MS and enhanced immunity from diseases such rickets, pneumonia, and tuberculosis
Cardio-metabolic Health
Sun exposure is also linked with lower blood pressure, decreased risk of heart attack and stroke, and overall better cardiovascular and metabolic health.
Conversely, Vitamin D deficiency is linked with a 50% increased likelihood of having a heart attack, a 100% increased likelihood of dying from a heart attack, and higher rates of hypertension, diabetes (type 1 and 2), and obesity.
Mental Health
Sun exposure, especially in the morning, also helps with melatonin production and better sleep. Who wouldn’t like to sleep more soundly?
The precursor to melatonin, serotonin, is also boosted by sun exposure. Serotonin is the good mood neurotransmitter, with low levels of serotonin being associated with depression and seasonal affective disorder.
Being exposed to the sun and natural light is also associated with general feelings of well-being, calmness, focus, and sound mental health, whereas lack of sun exposure and Vitamin D deficiency are linked with higher rates of mental disorders, like schizophrenia and Alzheimer’s, and higher rates of cognitive decline.
The benefits of sun exposure outweigh the risks
Vitamin D supplementation is not enough. The vitamin D3 and associated photoproducts that result from sun exposure have unique health benefits above and beyond that which can be gained through foods or supplements. So getting some unprotected sun exposure every day, or at least a few times a week, is important.
In the grand scheme of things, the risks associated with excessive sun exposure (skin cancer) is small compared to the benefits of getting some unprotected sun exposure and preventing vitamin D deficiency (which is associated with all the bad business discussed above).
But there are still risks…so be sensible, practice safe sun
I’m not saying to never use sun protection, mind you, just not to always use sun protection.
Protecting yourself from getting too much sun is still important. Getting a sunburn is where this risks outweigh the benefits as sunburns are associated with higher incidences of both melanoma and non-melanoma skin cancers.
Protect your face with hats or sunscreen…
Also, protecting the face and head is always a good idea as sun exposure to these areas doesn’t result in as much vitamin D3 production as other areas of the body and are at a higher risk for over-exposure and skin damage.
Everywhere else, get enough sun exposure to support health but not so much as to get burnt
But getting some unprotected sun exposure is important, for all the reasons that have been discussed. Using sunscreen with an SPF of 30 will block reduce our body’s capacity to synthesize vitamin D3 by 95-98%, which can lead to deficiency.
If we block the sun 100% of the time, we won’t be able to boost our vitamin D3 production and gain all of the positive health benefits associated with adequate vitamin D levels, in addition to the benefits in other physiological and cognitive functions, like those seen with enhanced melatonin and serotonin production.
The take home message is that sun rays aren’t all harmful, they’re also beneficial to us, leading to improved physical and mental health and protecting us from disease and decline. But there is a balance.
So what is “safe” sun exposure?
Most doctors and scientists agree that getting some unprotected sun exposure, without blocking rays with SPF or clothing, is crucial to maintaining healthy vitamin D levels and that the benefits outweigh the risks.
So what’s the right sunshine dose?
Unfortunately, that’s not an easy answer as it will be different for everyone depending on skin pigmentation, where we live (including latitude, altitude, and pollution levels), if we’re exposed to the sun unfiltered or exposed through glass or plastic, the season, and the time of day.
The right dose of sun exposure is one that allows our bodies to synthesize vitamin D3, boosts our other health functions, and protects us from disease yet doesn’t damage the skin (i.e. getting sunburned).
Getting outside with exposed skin should be done every day but only as long as your skin can tolerate without burning.
Estimating your “safe” exposure
The recommended “dose” is determined by estimating how longit would take for you to develop a light pink sunburn 24 hours later and exposing yourself unprotected for half that time.
For example, if it would take 30 minute for you to wake up with pink skin the next day, go protection free for 15 minutes, then apply sunscreen and protective clothing or seek some shade.
Most people can be outside for at least 10-15 minutes without burning, especially in the morning or late afternoon hours and when the UV index is below 3. Many people can be outside for much longer without incurring skin damage, but each person is unique.
Take brief excursions outside throughout the day
As I mentioned in the previous “get outside” post, getting outside for brief stints throughout the day is beneficial for our physical and mental health. This goes for sun exposure, too.
By getting outside for a few minutes a few timesa day you minimize your risk of skin damage while also getting in those beneficial sun rays; boosting your vitamin D production, getting a mental boost, and helping you sleep better at night.
We each have to figure out our own sun sweetspot but getting outside each day, even when the sun is behind some clouds, is a natural boost for our health and happiness. And it’s free :)
As always, thanks for reading my post!
References for my nerd friends (with links)
Mead M.N. (2008). Benefits of sunlight: A bright spot for human health. Environmental Health Perspectives, 116(4), A160–A167.
Paddock, C. (2013, May 8, ). Sun exposure benefits may outweigh risks say scientists. Medical News Today. Retrieved from http://www.medicalnewstoday.com/articles/260247.php
Wacker M., & Holick M.F. (2013). Sunlightand vitamin D: A global perspective for health. Dermatoendocrinology, 5(1), 51–108. doi: 10.4161/derm.24494
