Benefits Of Sunlight

I'd like to share with you some amazing new research about the benefits of sunlight to your health.

Sunlight powers life on Earth. All of life is highly adapted to absorb sunlight. You just have to look at your plants as they desperately grow towards the sun. Trees are arranged as antennae to capture as much sunlight as possible. In photosynthesis, plants absorb UV light to grow. Research is now revealing how important light is to humans too. Just like food, light is an energy source, a nutrient that we require for life.

Light is the ultimate super nutrient.

Sunlight has a wide spectrum of wavelengths, but as we only "see" the visible spectrum, we often forget about the other wavelengths. In a similar way to plants, our bodies have developed to soak up the sun’s rays and harness it for cellular regeneration and to help us fight infection.

Infrared waves penetrate through our clothes deep within our bodies. This energises our mitochondria (the batteries of our cells) and helps our cells to function. Mitochondria control our health and our ageing, so exposure to infrared light will result in healthy mitochondria and extend life. 

Modern humans now spend most of their time indoors. This is behind highly efficient window glazing which has been developed specifically to only transmit light from the visible spectrum - and our light sources within our buildings are LED lights. Again, highly energy efficient but also only emit light in the visible spectrum. Research shows that in environments where LED light sources are the only source of light, our cells become dysfunctional and we can become unwell. An example of this - astronauts in space exposed solely to white LEDs become ill due to mitochondrial starvation. This modern “visible light only” environment is a recent development as we have moved away from tungsten light bulbs which did emit a much wider spectrum of light, especially in the infrared. Remember how hot old filament bulbs were? That heat was from infrared light.

Humans absorb the sun’s ultraviolet rays through our skin. The dangers of UV light on our skin have been well publicised but new data is emerging that indicates the dangers have been overstated and the benefits of UV light have been understated. Skin cancer is caused by overexposure to UV, specifically sunburn in childhood, so while the advice is still to avoid sunburn, we do need UV light!

Skin colour is an evolutionary adaptation to different amounts of sunlight in the world. Paler skin has evolved in humans who moved from Africa to lower light environments, in Europe and Asia, to improve the uptake in UV light. So as humans moved away from the equator and the concentration of UV rays reduced, why would paler humans evolve to absorb UV light more efficiently, if UV light was of no benefit? There must be innate benefits to sunshine.

The leading cause of premature death worldwide is high blood pressure, leading to heart attacks and strokes. Blood pressure correlates with latitude and season. Everyone’s blood pressure is lower in the summer than winter. So when UV exposure is higher, blood pressure is lower. This seasonal effect has a bigger effect on reducing blood pressure than blood pressure reducing drugs! The death rate is always higher in winter: a fact we all accept. You are 30% more likely to die in January than July - but why? 

In recent years, the benefits of vitamin D have been publicised as if it is a perfect replacement for UV light, one tablet at a time. This isn’t correct. Vitamin D is only an indicator of a person’s exposure to UV light, and while this correlates with lower blood pressure and heart disease, this isn’t the result of vitamin D. Instead, this is from UV light.

Research shows that UV light on our skin activates the release of nitric oxide which dilates our blood vessels, so reducing blood pressure and heart rate. This lowered blood pressure reduces the risk of heart attacks by 20%! 

So the benefits of sunlight for the British population, with our low UV exposure, vastly outweigh any hazards. This beneficial effect goes beyond blood pressure. In fact, all causes of mortality in high latitude countries are lowered by sunlight, including cancers. UV light increases our immune response, so we are far more able to deal with new infections and cancer.

Sunlight makes you live longer, reduces your blood pressure and reduces mortality. 

We have evolved over two billion years in sunlight with its balance of ultraviolet, visible and infrared light. Both UV and infrared are showing to be critical to our health yet no longer form a significant part of our lives, as we spend 90% of our time indoors.

Sunlight is vital to our health. So, try and spend part of your day outside - just remember your sunglasses!

References:

The Infrared Revolution: New Frontiers in Light & Health

Sunlight: Time for a rethink?

Link to a recent paper from Richard Weller Professor of Dermatology at Edinburgh University: Sunlight :Time for a Rethink

Higher ultraviolet light exposure is linked with lower mortality