For years we’ve been told that the main reason to go out in the sun is to make vitamin D. But that is not all there is to it.
A new study by Professor Glen Jeffery and his team at University College London found that longer wavelengths of sunlight, particularly in the near infrared range, don’t just stop at your skin. They can pass through the body, even through clothing, and have effects on tissues far away from where the light entered. In their study, exposing the chest to these wavelengths improved visual function 24 hours later, even though the participants’ eyes were never exposed to the light itself.
Light entered through the chest, travelled through the body, and the eyes benefited a day later.
The researchers believe this happens because these longer wavelengths support the mitochondria, the tiny energy-producing structures inside our cells. Better mitochondrial function means more ATP, the energy every cell relies on to repair, maintain itself and function properly.
This is another reminder that the human body is far more intelligent than we’ve been led to believe.
And this isn’t new information because many natural healers were encouraging regular sunbathing well over a hundred years ago. They didn’t have modern scanners or infrared sensors, but they could see that people recovered better when they had fresh air, sunlight, good food, rest and clean water.
Florence Nightingale understood this too. She insisted that patients should spend time in sunlight whenever possible and she believed fresh air and natural light were essential parts of recovery, not luxuries. Even hospitals of that era were often designed with large windows, balconies and dedicated areas where patients could rest outdoors because sunlight was considered an essential part of good care. Some tuberculosis sanatoriums even built entire wards around open-air verandas, where patients spent hours outside every day.
But somewhere along the way, much of that wisdom was forgotten. Modern hospitals often have sealed windows, fluorescent lighting and patients who may barely see daylight for days.
Now science is beginning to rediscover some of what earlier generations observed through experience.
This latest paper also fits with years of research into red and near infrared light therapy.
Previous studies from Professor Jeffery’s group have shown that brief exposure to deep red light can improve colour vision in older adults by supporting mitochondrial function in retinal cells. Of course, this doesn’t mean sunlight is a cure-all, and it doesn’t mean you should spend all day baking in the intense midday sun. Like most things in nature, there’s a balance. But perhaps we’ve become so focused on avoiding the sun that we’ve forgotten what we’re avoiding.
Our ancestors lived outdoors. Children once played outside from morning until evening. Patients were wheeled into the sunshine because it was considered part of healing.
Sunlight is one of the basic requirements for health, alongside rest, clean water, fresh air, appropriate nutrition, movement and emotional wellbeing.
Maybe the question isn’t whether sunlight is medicine. Maybe the question is what happens when we spend most of our lives under artificial lights, behind glass, in offices, cars and homes, missing one of the most fundamental inputs our bodies evolved with…
Sometimes the oldest advice turns out to have been the wisest all along.
