After years of working in the skin care industry, one common piece of advice I’ve heard over and over again is that you MUST wear sunscreen every day, rain or shine, to prevent both skin cancer and premature skin aging.
Unfortunately, this advice has led many people to be afraid of going out into the sun without sunscreen. These are both possible outcomes if you spend too much time in the sun. However, a growing body of scientific research suggests that completely avoiding sunlight isn't such a good idea. Sunlight is important for so many biological processes, such as vitamin D production and supporting your circadian rhythm.
In this post, I’m going to explain the benefits of safe sun exposure, as well as discuss whether or not you should stop using sunscreen.
Have we been deceived by the sunscreen industry?
Like many other industries, the sunscreen industry has one primary focus: MONEY. Sunscreen was initially created to allow people to tan without getting burnt, not because we needed protection from the sun. However, when the sunscreen companies realized how profitable it was, they turned the sun into our enemy. We have been deceived by the sunscreen industry to believe the sun is bad for us for their commercial gain. 
According to Dr. Al Sears, MD, “any evidence that exposing yourself to the sun is harmful evaporates under scrutiny. It’s nothing more than conjecture and slivers of evidence blown out of proportion for commercial interests. What’s worse; if you follow this “no safe level of sun exposure” dogma, you’ll put yourself at greater risk of numerous deadly cancers, depression, bone loss, heart disease, diabetes and more.” 
Dr. Sears goes on to explain that “the sun is our best friend when it comes to feeling good, staying fit and avoiding disease (even skin cancer) because it is our primary source of vitamin D.” 
Now that you’ve had a glimpse of how important the sun is to our health, let’s discuss the specific benefits of sunlight.
6 Health Benefits of Sunlight
1. Vitamin D production
Did you know that sunscreen lowers your body’s ability to make vitamin D by up to 95 percent? 
When your skin is exposed to sunlight, it makes vitamin D from cholesterol. Specifically, the sun's ultraviolet B (UVB) rays hit cholesterol in the skin cells, providing the energy for vitamin D synthesis to occur.  Vitamin D promotes calcium absorption and is essential for bone growth and formation.  Vitamin D also improves the immune system, helps prevents cancer, and is important for brain function. 
2. Decreases risk of getting cancer
As mentioned above, one of the benefits of getting vitamin D from the sun is decreased risk of cancer. Check out these studies that have found how sun exposure and vitamin D are associated with lower chances of getting cancer:
A study published in the journal Anticancer Research says very clearly that the more you make vitamin D from UVB rays, the lower your chances are of dying from 15 kinds of cancer. 
A study published in the Lancet Journal states that the skin's exposure to ultraviolet radiation of short wavelength (UVB) has been associated with a decreased risk of melanoma. 
A study published in the European Journal of Cancer assessed a study cohort that consisted of 416,134 cases of skin cancer and 3,776,501 cases of non-skin cancer as a first cancer extracted from 13 cancer registries. The conclusion of this study states that Vitamin D production in the skin seems to decrease the risk of several solid cancers (especially stomach, colorectal, liver and gallbladder, pancreas, lung, female breast, prostate, bladder and kidney cancers). 
3. Maintain circadian rhythm
The human eye contains photosensitive cells in its retina that directly affect the brain’s hypothalamus region, which controls our biological clock. Stimulation of these important cells comes from sunlight, in particular, the blue unseen spectrum.  Going out in the sun first thing in the morning is important because your body will increase production of serotonin. Serotonin regulates mood, appetite, memory, and sleep. It is also the precursor to melatonin, which helps control your sleep and wake cycles. Bright light in the morning (i.e. sunlight) also increases production of cortisol like it does with serotonin, which further helps us to wake up. 
4. Boosts your mood
Moderate sunlight exposure helps improve your mood and focus by boosting the levels of the feel-good neurotransmitters serotonin and dopamine. Higher levels of serotonin correlate with better mood and feelings of satisfaction and calmness, and lower levels link to depression and anxiety.  Dopamine influences vital brain functions that affect mood, sleep, memory, learning, concentration, and motor control. The right balance of dopamine is vital for both physical and mental wellbeing.  There’s also evidence that UV light can push melanocytes (the cells that produce dark pigment in skin) to release endorphins, a feel-good chemical. 
According to an article published by Time, the correlation between sunlight and mood emerged with a condition called Seasonal Affective Disorder, or SAD. The term was coined by Dr. Normal Rosenthal at Georgetown University to describe the “winter blues” aka the lethargy and feelings of sadness and hopelessness that come when the weather forces people to spend more time indoors and the season provides little opportunity for exposure to natural light. It is even speculated that our modern lifestyle, which keeps people indoors under artificial light for so many hours, may be encouraging a form of SAD year-round. 
5. Promotes weight loss
Another interesting benefit of safe sun exposure is its ability to reduce body fat. In a University of Alberta study, researchers found that subcutaneous fat cells (white fat cells found right beneath your skin) shrink under sun’s blue light. Peter Light, senior author of the study, explains, “When the sun’s blue light wavelengths—the light we can see with our eye—penetrate our skin and reach the fat cells just beneath, lipid droplets reduce in size and are released out of the cell. In other words, our cells don’t store as much fat.” 
6. Boosts immunity
As mentioned above, sunlight stimulates vitamin D production, and vitamin D plays a role in immune function. Research also indicates that low levels of blue light, found in sun rays, makes T cells move faster.  A T cell is a type of lymphocyte which develops in the thymus that plays a central role in the immune response. A study published in Scientific Reports shows that sunlight directly activates key immune cells by increasing their movement. 
Negative consequence of sunscreen
Of course, one of the main negative consequences of using sunscreen is that you’ll deprive your body of all the benefits described above that sunshine naturally provides!
But did you know that certain sunscreen ingredients come with many undesirable health effects? I am talking about sunscreen ingredients that are classified as “chemical sunscreens”, such as avobenzone, oxybenzone, octocrylene, homosalate, and ecamsule. These ingredients are absorbed into the skin and work by first absorbing UV light, then transforming that light energy into some other form of energy, such as heat.
A recent study in the Journal of the American Medical Association (JAMA) confirms these active sunscreen ingredients seep into your bloodstream after just one day of use.  In addition, most sunscreens contain fragrances and stabilizers that mimic hormones, irritate your skin, and mess with your system in other ways.14 Here are some facts on specific chemical sunscreen ingredients:
Oxybenzone: linked to hormone disruption and cell damage that may lead to skin cancer. 
Octyl-methoxycinnamate: causes oxidation damage of the skin, which ages your face. 
Butyl Methoxydibenzoylmethane: releases free radicals into the body. 
Benzophenone 2 (BP2): decreases the function of the thyroid. 
So should you stop using sunscreen?
While this blog post has outlined the very important benefits of getting safe sun exposure every day, it should be noted that excessive sun exposure is still deleterious to your health. UVA radiation 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. Too much UVB radiation causes sunburn and also leads to direct DNA damage and promotes various skin cancers. Both forms of UV radiation can damage collagen fibers, destroy vitamin A in skin, accelerate aging of the skin, and increase the risk of skin cancers.16
So what exactly is ‘safe sun exposure’? Well, there’s no clear cut answer since everyone is different! One recommendation is to spend 10 to 30 minutes in direct sunlight every day (in the morning if possible). If you start to burn, you’ve gone too long. Scale it back by a couple minutes next time.
If you’re going to be in the sun longer than this amount of time, use a broad spectrum SPF 30 sunscreen. I personally recommend a mineral sunscreens since they are much safer than the synthetic chemical sunscreen ingredients mentioned above. Mineral sunscreen ingredients (i.e. zinc oxide and titanium dioxide) work by blocking or deflecting UV light, rather than being absorbed by the skin. Here are some of my favorite mineral sunscreen products:
Paula’s Choice Essential Glow Moisturizing SPF 30 is a fragrance-free, illuminating face moisturizer that shields skin with all-mineral sun protection (Titanium Dioxide 5.25% and Zinc Oxide 6.12%) plus antioxidants to help protect against the effects of environmental damage. I love this moisturizer because it not only provides sun protection, but also provides skin-soothing and replenishing ingredients, such as licorice root extract, argan kernel oil, linoleic acid, niacinamide (vitamin B3), bisabolol, phospholipids, lecithin, and more.
Coola Mineral Body Sunscreen Lotion SPF 30 is a fragrance-free, hydrating body sunscreen that utilizes “genre-defying technology” to help disperse non-nano minerals (Zinc Oxide 14.0%) evenly, for a sheer application with a lightweight and eminently wearable finish. This sunscreen also provides several skin-soothing and replenishing ingredients, such as algae extract, bisabolol, shea butter, meadowfoam seed oil, avocado oil, raspberry seed oil, and more.
6. Anticancer Res. 2006 Jul-Aug;26(4A):2687-99.
7. Eur J Cancer. 2007 Jul;43(11):1701-12. Epub 2007 May 30
16. Environ Health Perspect. 2008 Apr; 116(4): A160–A167.