The Effect of Light
Light is the most important environmental signal for setting the circadian body-clock.
There appears to be a relationship between the level and quality of environmental light and the body’s production of a hormone called Melatonin. This hormone is produced only at night and its production is inhibited by light.
When our eyes become aware if the rising light levels at dawn, the level of melatonin begins to drop and the level of cortisol begins to rise. This process happens quite quickly, in around twenty minutes, and the balancing of these hormones will contribute to our rising alertness.
Melatonin is synthesized from tryptophan, an amino acid found in some foods, and it is converted over several steps into serotonin, and then melatonin. In the next section we will look at foods which might help improve your sleep.
Low levels of exposure to light can also begin to affect our mood. If you are sleeping a lot during the day, and reducing your exposure to light, or if you live in a northerly place where low light levels in winter affect your mood or symptoms, you might try using a light box to boost your daily exposure.
Next: Resetting the Clock