Falling Into Bed By 10
Fall has always been a time of new beginnings for me - the start of a new school year with new teachers, classmates, classes, and the return to a more regular schedule after the freedoms, expansiveness, and later bedtimes of the summer. As we move into fall, I’m noticing that sunset is coming noticeably earlier and I’m starting to feel a pull to wrap up my evenings and go to bed earlier.
And until the advent of artificial light, this is what people have always done – we’ve followed the rhythm of the sun and the seasons. Despite the many wonderful advances in technology and artificial lighting over the past couple hundred years, our bodies have not caught up; biologically, we still follow the same circadian rhythm as our ancestors did centuries ago.
So, what is the circadian rhythm? It is a roughly 24-hour cycle of day and night, of activity and rest, which affects not only humans, but also animals, plants, fungi, and even cyanobacteria. In humans, the circadian rhythm affects the sleep-wake cycle, fluctuations in core body temperature, heart rate, and many cellular processes. Two important hormones for circadian rhythms whose levels fluctuate daily are melatonin and cortisol. Their rise and decline complement one another, just like the two halves of the Yin/Yang symbol.
Melatonin is secreted by the pineal gland in response to the decreased light that normally happens in the evening; its levels rise about two hours before bedtime and are naturally highest at night. The body’s melatonin production is suppressed by exposure to sunlight in the morning and to blue LED light (found in electronic screens any time of day), so it’s important to limit the use of screens in the evening. Synthetic melatonin is often suggested for people who have trouble falling asleep. The proper dosage, according to a 2001 study from the Massachusetts Institute of Technology, is 0.3 milligrams, about 1/10th of the amount in most pills or supplements. Because melatonin supplements are used to reset the body’s circadian rhythm, they are useful for jet lag, but should not be taken more than a few days. Do not use melatonin if you are pregnant or breastfeeding or have an autoimmune disorder, a seizure disorder or depression.
Cortisol, a hormone secreted by the adrenal glands, rises rapidly in the early morning, allowing us to be awake and alert, and gradually declines during the day, causing us to get sleepy at night. Its levels are highest in the morning. Cortisol levels also increase due to acute stress (think of the burst of energy you get when in “fight or flight” mode), during periods of chronic stress, and in response to meals. High cortisol levels can contribute to insomnia. Cortisol also spikes in response to caffeine. So when you drink coffee or tea to get going in the morning, you are artificially raising your cortisol levels to induce the hormonal response your body would normally produce on its own with sufficient sleep.
Fall, with its association with new beginnings, is the perfect time to introduce new routines and establish healthy rhythms. Having regular habits, such as going to bed and getting up at a regular time, helps your body to anticipate what’s coming next and to develop stability and reserves for future stressors. More sleep improves energy and balances hormone levels. This year, I invite you to join me in getting yourself to bed by 10 pm and together we'll see what a difference it makes.
