#1109 - Matthew Walker
The power of light on human health and well-being.
Our eyes are not only for seeing. The human eye has cells which are designed to detect light that send signals to the region of the brain responsible for our vision. But these cells also send signals to the region of the brain that controls our circadian system (body clock).
The human body is programmed to function on a 24-hour internal clock that matches the solar day. Known as the circadian rhythm, this clock is synchronised by light and controls many aspects of our physiology, metabolism, and behaviour, including our sleep-wake cycle.
Melatonin is a hormone produced by the brain that plays an important role in the regulation of our sleep wake-cycle. Melatonin production starts to increase in the evening, peaks in the middle of the night and rapidly declines in the morning, allowing us to wake-up. Exposure to blue enriched LED light or Bright light before bedtime can lead to melatonin suppression, which can delay sleep onset and shorten sleep duration. It has been shown that by having 10 minutes exposure to this type of right before bed and suppress melatonin by 50% which is a huge number.
Study’s show 40% of Australians suffer from inadequate sleep and poor sleep is linked to a huge range of impaired health issues like heart disease, diabetes, depression, anxiety, hormone imbalance, cancer, unhealthily eye development and more.
Inversely, exposure to blue-enriched bright white light at the right time of the day can have positive effects on the human body, increased alertness, improving mood, energising effect and improve wellbeing.
It’s no secret that artificial lighting has opened the door to immense progression, allowing us to extend our daily activity into the night hours. Nevertheless, the indiscriminate use of artificial light has impacts. Its Just about ensuring we use it to our full advantage.