Have you ever noticed that some days you’re “on”—and some days you’re decidedly not? Are you more productive at some times than others? Do you push yourself to keep going when you’re tired? Do you ever just feel out of sync?
Before electric lighting dominated our world, we lived by the cycles of the sun and moon. We awakened with the sunrise, were active in the daylight, and gathered around the fire as darkness fell. This way of life wasn’t merely convenient; it turns out to be vital to our physical and mental functioning, our moods, and even our survival. In fact, many researchers believe that being synchronized with natural light-dark cycles is the basis of good health.
Living indoors, it’s easy to forget that our bodies have been intimately linked with natural cycles since life began. But it makes sense: As life evolved, the influence of the sun and moon were constant; organisms had to adapt to the cycles of day and night, a waxing and waning moon, and the seasons if they were to thrive.
In our own bodies, we have daily, monthly, and seasonal cycles of sleep and wakefulness, temperature, blood pressure, hormone secretion, cell division, and virtually all functions. These processes are triggered by changes in light level, air temperature, and other environmental factors.
Morning and evening are especially significant times for resetting our inner clocks. Awakening gradually with the sun, which stimulates the hormone serotonin, allows our body to peacefully resolve its sleep cycles and prepare us for the day. If we are in tune, our heart rate, blood pressure, body temperature, and cortisol (a hormone that defends against stress) level increase before we wake up. In the evening, these functions should decrease, while darkness triggers increased production of the sleep-inducing hormones melatonin and prolactin.
Both women and men experience monthly cycles in hormone production and other bodily processes. Many people believe that women’s menstrual cycles were once regulated by the cyclic changes in moonlight. Electric lighting, including streetlights, may throw off those cycles, resulting in menstrual irregularities, infertility, premenstrual depression, and difficult childbirth.
Our annual body cycles follow the seasons: As the days lengthen toward summer, our daily alertness phase also lengthens; our hearts and lungs handle exercise better; and we need less sleep. In winter, we become slower, we sleep longer and more deeply, we eat more, and we store body fat more easily; we move toward hibernation.
In earlier times, people honored their seasonal cycles because they had to. In cold winters, they huddled in their shelters around a fire. They wore extra clothes, moved around less, ate more starch and fat, and slept more during the longer nights. Among some Native American tribes, this was known as the Dark Lodge time; they told stories, repaired tools, and made clothing and ceremonial gear. I can’t help but notice that they were also allowing a quieter, more magical part of their psyches to emerge—something we rarely do now. I also doubt that they were plagued by seasonal affective disorder (SAD, a type of depression triggered in many people by the reduced sunlight of winter) because it probably never occurred to them to operate at summer’s high energy levels.
The dangers of desynchronization
These days most of us tend to be out of sync. We get too little sleep, awaken by an alarm clock, jump-start ourselves with caffeine and sugar, work indoors under steady levels of electric light all day and into the evening—and then have difficulty sleeping. Not only are we out of harmony with the sun and moon, but our complex biological functions get out of phase with each other.
Natural, full-spectrum light is a necessary nutrient. When it enters our eyes, it activates our endocrine system, which is connected to our immune system and our nervous system. Under harsh fluorescent lights, we are missing the portion of the sun’s spectrum that is vital in triggering the production of a proper chemical balance of melatonin and serotonin. When this “desynchronization” occurs, our health declines. We may become tired, depressed, or anxious; our sleep may be disturbed; digestion and metabolism can be thrown off; and we generally become more vulnerable. All of these are common complaints, but how often do we realize that we may be out of sorts because we’re estranged from our natural rhythm?
Studies are beginning to show the consequences of desynchronization. Night nurses have significantly higher rates of heart attacks and breast cancer than the general population (up to 70 percent higher in some studies). Rotating shift workers have increased coronary artery disease, sleep disorders, respiratory problems, lower back pain, intestinal disorders, job stress, emotional problems, injuries, and drug and alcohol abuse. Those of us who routinely go to sleep at night may not suffer such extreme symptoms, but they are a warning of how serious desynchronization can become.
Get your groove back
It won’t surprise regular readers of this column that all of this points to some simple solutions: daylighting, passive solar heating, outdoor living spaces, and greater contact with the natural environment. Gradually awakening with the sun, working near windows, getting outdoors during the day, and turning down lighting levels toward bedtime can make a radical difference in how we feel. If you want to restore your natural rhythm, you will have to squarely face the ways of our culture. It takes planning and mental fortitude to buck the do-more/sleep-less/ignore-nature/take-a-pill-if-it-hurts culture. But the price of running with the pack is high—and you might even be more productive and energetic if you stop working against your body cycles. You don’t have to change your whole life at once; you can try one simple change that appeals to you, then another.
For years, I have wanted to move toward harmony with natural cycles. It’s taken a while to change some habits, but my efforts are paying off. I used to stay up late, sleep late, and feel lousy, but I gradually shifted so that I now awaken with the morning sun; I use an alarm clock only on the rare occasions when I need to get up extra early. I feel much better. I get outdoors every day. I moved my desk near the windows, and I work by daylight most of the time. And—the hardest part for me—I’m learning to slow down in the evenings and keep lighting levels low; it feels good to end the day by candlelight.
Urban planner Carl Anthony tells a lovely story about neighborhoods that lost electricity after the Loma Prieta earthquake in northern California. Unable to watch TV or turn on lights, people drifted outdoors in the evenings and began to talk with neighbors they barely knew. Community was forged as they rediscovered “the essential darkness of night.” Maybe a hidden gift of resynchronization is that we can slow down and find each other. Perhaps we can even find parts of ourselves that have been driven into the shadows. Maybe the good life begins with something as simple as turning off the light.
Carol Venolia is an architect, author of Healing Environments: Your Guide to Indoor Well-Being (Celestial Arts, 1988), and former publisher of Building with Nature Newsletter.