Imagine lying in a windswept meadow with soft, diffused sun rays beaming down on you and a gentle breeze blowing around you. It’s a calming scene for many. We tend to associate sunshine and fresh air with happiness and peace.

With the arrival of Spring, the sun’s rays are hitting the Earth in a more direct way, giving way to warmer days and ample opportunities to get outside. If you’ve ever noticed the rejuvenating effects of being outside on a sunny day, you’re not imagining things–the benefits are real.

Sunlight and fresh air can help you avoid or shorten respiratory infections, reliably disinfect linens and fabrics, synthesize needed vitamin D, control cholesterol levels, and regulate mood.

Benefits of Sunlight and Fresh Air

People have believed in the power of sunlight and fresh air for centuries. Florence Nightingale, famous for caring for British soldiers during the Crimean War as a nurse, recommended that patients’ windows be kept open as much as possible without making the patient cold.

She also knew about the disinfectant properties of sunlight before they had been proven: “It is the unqualified result of all my experience with the sick, that second only to their need of fresh air is their need of light, and that it is not only light but direct sun-light they want.”

Fast-forward to today, and although science has made tremendous progress, we’re finding that much of what we believed about the power of sunlight in centuries past was correct. Additionally, we are learning that sunlight and fresh air provide more benefits than we knew about.

1. Clears up infections

A 2011 study from a Chinese university found that dorm rooms with the lowest rates of ventilation were associated with higher instances of respiratory infections.

Even the World Health Organization (WHO) confirms that natural ventilation–allowing fresh air to circulate–is an important part of infection control. They recommend natural ventilation as a means to reduce infection risk at healthcare facilities. You can get the same benefits at your home or office by opening the windows and getting a backdraft of fresh air going.

2. Boosts mood

A 2015 study on Seasonal Affective Disorder (SAD) found that increased exposure to sunlight may increase levels of a “natural antidepressant in the brain.” The study tracked the participants’ levels of the neurotransmitter serotonin on sunny and cloudy days.

They found that on sunny days, the brain tended to produce more serotonin and on darker days, the brain produced lower-than-normal levels of serotonin. The researchers said this is evidence that reduced serotonin levels over time, whether by cloudy weather or staying primarily indoors, can be a factor in the development of SAD.

Symptoms associated with SAD include:

  • Difficulty concentrating
  • Low energy or fatigue
  • Loss of interest in daily activities
  • Moodiness
  • Sleeping more than usual

In addition, these symptoms must be experienced in the winter season or along with a seasonal change.

Sunlight (phototherapy) helps ease the symptoms of SAD by raising the brain’s serotonin levels. Some doctors recommend artificial lightboxes for this reason. However, natural sunlight provides additional benefits that lightboxes and special bulbs do not, like synthesizing vitamin D and lowering cholesterol.

3. Disinfects naturally

Numerous studies have shown that both exposure to natural sunlight and fresh air are effective disinfectants that kill bacteria.

When bacteria comes into contact with fresh air, something called the open-air factor occurs. The open-air factor phenomenon refers to when compounds in the air act as a disinfectant that kills germs and pathogens. Bacteria survive in closed areas better than when they’re exposed to fresh air.

When microbes that cause infection and disease are exposed to natural sunlight for extended periods of time, the Journal of Hospital Infection states that “…the majority of microbes that cause airborne infections cannot tolerate sunlight.”

4. Increases vitamin D + lowers cholesterol

Cholesterol is the precursor to vitamin D. Did you know that both are formed in your skin? When you expose your skin to sunlight for an extended period of time (15 minutes or more), the cholesterol in your skin begins to transform into vitamin D.

The sunlight is the additional energy needed to turn potentially-dangerous cholesterol into a vitamin your body needs and may be deficient in. It’s a win-win!