Health Benefits Of Sunlight

Sunlight is essential for human well-being and overall health. Bright light— but particularly blue wavelength light like what the sun emits— has many positive effects on the human body. Despite our lives being spent indoors either in our apartments, working 9-5 jobs, or stuck in traffic in our cars, it is still essential we get sunlight exposure throughout the day.

Here are 10 health benefits of sunlight exposure.

Improves Happiness & Reduces Stress

Serotonin, also known as the happiness hormone, is typically produced during the day. When we are exposed to darkness serotonin converts to melatonin which helps us fall asleep. Scientists have studied the brains of people post-mortem of those who died in the winter and who died in the summer. Research proved that those who died in the summer had more serotonin in their brains. This can also be what causes the phenomenon known as Seasonal Affective Disorder. Less exposure to sunlight means less serotonin produced in the brain.

Cortisol, the hormone best known for keeping us awake, can become elevated when the body is exposed to excess stress. Chronically elevated cortisol can wreak havoc on the body resulting in excess fat gain and sleep disturbances. It can even cause the memory center in the brain to shrink.

However, exposure to bright light may help reduce stress. In a study conducted where people were exposed to short wavelength light (blue light) for 6.7 hours, researchers found that the participant’s cortisol levels decreased by up to 25%. While spending close to 7 hours outdoors a day may be hard to do today it is clear that if you spend the entire day indoors you run the risk of boosting your cortisol by up to 25%.

Improves Brain Speed & Increases Sex Drive

In a study done at the University of Arizona, researchers exposed adult participants to 30 minutes of bright blue light meant to mimic the wavelength of sunlight. Afterward, they studied their brain activity with an fMRI machine and found that the bright light exposure activated the participants’ prefrontal cortexes. This is the part of the brain that is responsible for “higher order” aspects of cognition such as decision-making, planning, and certain aspects of personality. The light also sharpened their mental acuity. Participants were able to display increased reaction times and processing speeds on tests as compared to the participants who were exposed to amber-colored light.

In a trial involving 38 males who were experiencing low libido and low sexual satisfaction, half were exposed to full spectrum light, which was meant to mimic sun exposure, for 30 minutes a day for 2 weeks. The other half of the group was the placebo ground that was exposed to a “sham” light instead. The trial found that the men who were exposed to the blue light experienced an improvement in sexual function that was 3 times as great as the placebo group. The blue light group also saw a 70% increase in testosterone from their baseline.

Boosts Immune System Function & Protects Against Nighttime Screen Exposure

A study conducted at Georgetown University found that blue light actually “activated” T cells, which are a category of immune cells, and caused them to move around faster. While this was a study conducted in a petri dish and not in a living body, researchers found that the blue wavelength light was able to penetrate the skin where it can then reach these cells. This study suggests that the sun can act as a hormetic stimulus and create mild “stress” at the cellular level. This stress then activates gene pathways that are involved both in protection and repair. Therefore your immune system can receive a boost after being exposed to sunlight.

Technology has harmed our health by exposing us to amounts of blue light even into the nighttime. Our ancestor’s eyes were only ever exposed to amber-colored light from fire once the sun had set. The unprecedented amount of blue light exposure we are getting suppresses melatonin which not only helps us sleep but also aids in healthy immune function.

A small study was conducted in Japan where researchers found that exposure to daytime blue light was able to prevent light-induced melatonin suppression at night. This study suggests that by going outside and receiving blue light exposure from the sun you can more safely use your electronic devices at night.

Improves Sleep & May Help Protect Your Eyes

Exposure to sunlight or very bright artificial light in the morning helps your body produce nocturnal melatonin earlier in the day which in turn helps you fall asleep more easily at night. Sleep is essential in keeping your hormones regulated. A happy healthy hormonal system connects to everything you do including making better dietary choices throughout the day.

While we don’t suggest going out and staring at the sun, there have been studies that show sunlight exposure may help with nearsightedness. Research has found that higher UVB exposure, which is directly correlated to time outside and sunlight exposure, is associated with reduced odds of developing nearsightedness. Exposure to UVB rays between the ages of 14-29 is also associated with a higher reduction in the odds of developing adult nearsightedness.

Regulates Healthy Gene Expression & Increases Lifespan

Circadian rhythm is the physical, mental, and behavioral changes we experience within 24 hours. It’s also known as your internal clock and it responds primarily to light and dark. Exposure to bright light in the morning is what sets the clock. Your circadian rhythm is responsible for regulating 15% of the human genome including genes that regulate hormones in charge of immune function, appetite control, and producing neurotransmitters.

Researchers tracked 29,518 Swedish women over the course of 20 years. They found that the women who had the most sunlight exposure lived longer and had less cardiovascular disease as compared to those who avoided the sun. Those who avoided the sun saw a reduced life expectancy of 0.6-2.1 years. Shockingly enough, cigarette smokers who had the highest sunlight exposure were at just as much of a risk of death and diseases as non-smokers who avoided sun exposure. The study showed that avoiding the sun canceled out the health benefits of being a non-smoker.