Have you ever wondered why you sleep less as you age? It’s not because you don’t need more sleep and can get by with less. It is because you had roughly twice as much sensitivity to light when you were a child. As an aging adult, your body responds with less melatonin and other hormonal signals for sleep.
But don’t worry, science has discovered a work-around: exposing yourself to more daytime light will improve your sleep at night.
Here’s what happens to our sleep as we age.
Circadian Rhythms
The daily rhythm that we follow is called the circadian rhythm. The part of the brain that oversees the circadian rhythms is the suprachiasmatic nucleus or SCN. It’s your brain’s central clock. We are sensitive to this clock, but not only for waking up and going to sleep. The SNC is the body’s master metabolic regulator and thermostat. It links to the hormone-secreting pituitary gland.
Light comes in through our eyes, which have numerous light-sensing proteins. One such protein is called melanopsin, and it’s not involved in sight. It’s only sensitive to blue light, and its purpose is to set the body’s internal clock.
Melanopsin trains the SCN to release hormones like cortisol and testosterone and it activates peristalsis, the movement of the bowels. It revs up the metabolic engine, burning through stored fuels.
But because we have lost 50 percent of our light sensitivity, our master clock doesn’t get reset properly. According to author Max Lugavere in Genius Life: Heal Your Mind, Strengthen Your Body, and Become Extraordinary, there is an efficient way to recuperate the regulation of your internal clock. You can reset it and regain your natural ability to sleep.
Fortunately, setting your master clock is as easy as exposing your eyes to bright light early in the day. Research shows that for melanopsin—your light-sensing protein—to entrain your brain’s clock, the SCN, about a half-hour of 1000 lux of light (approximately the brightness of an overcast day) is needed.
A Simple Solution to Sleep Better Naturally
If you take time to enjoy sunlight in the morning by taking a 30-minute walk, standing by a window, or engaging in any outdoor activity (without sunglasses), you can restore your natural circadian rhythm.
The problem is that the average American spends 93 percent of their time indoors. But that’s not the only problem. When we’re indoors, we’re using artificial light from bulbs, computer screens, and television. You can’t expect the brain to synchronize to natural rhythms if it’s confused what time it is.
Melatonin the Sleep Hormone
When the body thinks it’s daytime and it isn’t, the brain suppresses melatonin, the sleep hormone. Melatonin plays a vital role in the curative powers of sleep, but much more than that. In one study, researchers gave supplemental melatonin to patients with type 2 diabetes. Compared to the group that received a placebo, three months of supplementation of 10 mg of melatonin a day improved patients’ markers for inflammation, oxidative stress, blood sugar control, and other indicators of heart disease risk.
What Happens When We Sleep
Your brain and body stay remarkably active while you sleep. Recent findings suggest that sleep plays a housekeeping role that removes toxins that build up while you are awake. Everyone needs sleep, but its biological purpose remains a mystery.
After people sleep, they tend to retain information and perform better on memory tasks. Our bodies require long periods of sleep to restore and rejuvenate, grow muscle, repair tissue, and synthesize hormones. Now that’s an excellent reason to get good sleep. What senior doesn’t want that?
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