You’ve probably heard of melatonin and know that it’s related to sleep and the body-clock. You may have heard of it being used as a treatment for jet lag. You may also have heard about problems relating to sleep and the use of screens in the evening.
In humans, melatonin is mainly produced by a tiny gland in our brain called the pineal gland. The brain’s clock (or the Suprachiasmatic Nucleus for those of you who really want to know) tells the pineal gland when to start pumping out melatonin. Its production depends on whether it’s day or night. Or more importantly, in our modern lives with electric lights – whether it’s light or dark.
Light is picked up by light sensors at the back of the eye. They send messages to the brain informing it that it’s daytime and that it should stop producing melatonin. In the evening the eye tells the brain there’s less light and melatonin starts to be produced. As the evening goes on, levels increase.
Melatonin helps us fall asleep and to sleep well, but it does much more than that. It’s an antioxidant and prevents damage to tissues in our body and brain. It tells the rest of our body when it’s night-time including other hormones like insulin, the adrenal gland hormones and reproductive hormones. It is part of the system which controls the sugar and fat balance within our body. It also helps our immune system function.
Problems with melatonin levels may therefore have an impact on blood sugars and energy balance generally. Our ability to get rid of potentially harmful compounds in the body from its antioxidant effect may be reduced.
It’s not just humans who produce melatonin. It’s also found in fungi, yeast, fish, birds, reptiles and mammals. In animals the seasonal changes in the length of the days and nights result in an important increase or decrease in melatonin. The amount of melatonin tells the animal’s body what season it is, allowing it to adapt. For instance increasing appetite and food intake in the spring and summer in preparation for hibernation.
Melatonin medication has a number of uses. As we mentioned at the start it can be used if the day/night balance is disrupted by jet lag. It can be effective to improve insomnia in the elderly. It’s also used to help sleep routine in children with autism or attention deficit hyperactivity disorder (ADHD)
It’s being studied in various situations because of it’s role in regulating the immune system and it’s antioxidant properties for instance in Alzheimers disease, Multiple Sclerosis and Ulcerative Colitis. It’s also being studied in relation to it’s potential positive impact on body weight and glucose (sugar) control.
Levels tend to drop as we get older. Lower levels are also associated with diabetes if sugars are running high and with obesity.
Finally, there’s one other important cause of low melatonin that is potentially easy to fix and that is exposure to light at night. The electronic devices that are all around us are of particular concern as the screens often emit high levels of blue light – the same kind of light that is emitted by the sun. The blue light can delay the onset of melatonin production at night-time and prevent its levels from rising properly. It’s really important to be aware of this from our own perspectives and also from that of our kids.