We know that you already know this part: sleep is important.
Some of us buy smartwatches that track our sleep, swoon (literally) over the right mattress, and ingest sleep tonics with an enthusiasm usually reserved for that other hypenated tonic.
Some people even fly across oceans just to land at a sleep retreat – I know, Ive done it!
As usual, the problem can compound itself when you worry about it, causing even more sleep difficulties and sending you down the spiraling vortex.
Worrying uselessly kills you and is a whole different issue best addressed by this post here.
And while sleep, yes, is vital, what we don’t all know is that sleep is not the same as circadian rhythm, which governs all your biological systems.
What Is the Circadian Rhythm
Humans evolved to be highly sensitive to the 24-hour solar cycle.
Almost all organisms, including humans, have internal daily clocks (circadian rhythms) which “help regulate many of our physiological processes, including sleep, metabolism, hormone secretion, and even how our brain functions. Energy, alertness, and other biological processes can suffer when that rhythm doesn’t align with the clock one is actually trying to follow. The circadian and sleep processes are also very tightly related to your mental state and how alert you are. If you try to do something in the wrong time of day, your alertness is not going to be as effective as if you do it in the right time of day as defined by your circadian clock.”
Today, however, our circadian rhythms are subject to so much disruption, because we’re taking in light and dark in historically weird ways.
Ever-brighter, addictive screens trick our brains into the thinking its still daytime: there is a disconnect between natural solar time and our social clocks. The price of technological progress!
We have evolved to be in the light during the day, and since our body systems are managed by our circadian rhythm, we need to facilitate proper alignment of our internal “clocks” with our external realities – starting with the management of lighting.
That is, it’s the timing of sleep that is absolutely key to getting high-quality, restorative sleep. This means sleeping at the right circadian time, and the only solutions that can actually reset circadian rhythms are centered around light. Circadian rhythms cannot be meaningfully reset by exercise, stress-reduction, yoga, massage, food, etc.
Your Circadian Health Will Impact Your Longevity
In 2017, a group of researchers won the Nobel Prize in Medicine by discovering how ”clock genes” control our daily rhythms.
These genes controls not just when we sleep but also our heart rate and blood pressure, the immune system, metabolism, body temperature, hormones and even mood. These clocks are in our DNA.
Disruptions to our circadian rhythms, from those ever-increasing mismatches between our internal clock and lifestyle, when we override our natural cycles, have significant health consequences, including a higher risk of obesity, diabetes, some cancers, heart disease, depression, gut disorders, allergies, infections, premature aging—and early death.
There have been innumerable studies connecting light to health. People are hardwired with genes that make us night owls or early birds—called our chronotype.
Early risers’ daily peak performance occurs early during the day, while natural night owls’ occurs later.
Researchers estimate about 40 percent of people are morning or evening types, and 60 percent are in-between. Our chronotype impacts circadian cycles: Early birds have a faster internal clock, for example, whereas night owls have a slower clock, taking up to 25 hours to complete one cycle.
These internal clocks need to be reset, just like a watch, exactly 24 hours each and every day, and the light-dark cycle is the synchronizer.
For the first time in human history, we actually have nearly complete control on how much light we have at different times of the day, so we can program lighting in our indoor environments in ways that simulate midsummer or spring days.
Exposure to regular light-dark cycles provides the daily “time cues”we need to reset our circadian clocks and not only determines how well we sleep but our very cellular health. We need the sun’s bright blue light in the day to be alert and active, and we need dark to kick-start our brain’s sleep mode and recovery.
The circadian clock anticipates environmental time; it doesn’t reflect it or have anything to do with the “social” time of day.
The clock anticipates the timed physiology that will happen tomorrow, when we wake/ sleep, eat, etc., to ensure that we do these things at the right time. That is, your circadian rhythm is generated from within.
Here are a few things to try if you think your circadian rhythm is off:
- Maintain a consistent sleep and wake up time: and try to keep it close to what feels natural to you – i.e., don’t fight the fact that you are an owl or a bird – even a dog or an elephant! (elephants don’t sleep much, we really are not certain why!)
- Get light in the morning: Get sunlight in your eyes first thing in the morning when you can. Getting light early in the day tells your body it’s time to “wake up.”
- Avoid bright lights in the evening: avoiding bright lights in the evening and dimming your lights can make a difference.
- Avoid blue light at night: turn off the TV and other devices that emit blue light at least 3 hours before bed.
Circadian Travel: Treatment for Jet Lag
The travel industry—hotels, wellness resorts and airlines—has recently gone sleep-bananas.
There are scores of of sleep-focused wellness retreats, and sleep scientists are even designing entire resort sleep programs
Hotels and spas / retreats feature pillow ”menus”; sleep aromatherapy and massages; guided meditation; oxygen therapy; cryotherapy; special sleep workouts; and minibars and menus filled with sleep tonics, CBD and “sleep bites.”
These generic sleep solutions can help your overall well being but they are not strictly ”circadian” solutions and they have sero impact on the bane of all long-distance travelers: jet lag.
This is about to change.
The timing of light exposure—not sleep, exercise, food or caffeine—is key to eliminating jet lag and can be the difference between a successful trip or a miserable one. The right light exposure at the right time can significantly accelerate travelers’ adaptation to new time zones. Seeing light at the wrong time makes jet lag much worse.
Many companies and research centers are developing technology to tackle jet lag: Rensselaer Polytechnic Institute, for example, recently announced it has developed a wearable device that analyzes a person’s biometric info and can then recommend the right sleep and light schedule to re-optimize circadian rhythms. They say their bio-sensing tech that can tell you where you are in the circadian phase works in-line with clinical hormone measurements, and it would be a whole new approach to jet lag. (It’s being funded by the US Department of Defense.)
New lighting technologies are tunable, biodynamic and sync with the time of day. More people will likely bring circadian lighting and behaviors into their homes. Some of the changes are not exactly high-tech: adopting the routine of disconnecting from your devices and dimming the lights well before bed: banishing laptops and cellphones from the room. We know by now that restful sleep means avoidance of light.
You can make a simple switch in your lighting, too: using bright, short wavelength, blue-light bulbs in the day and switching to dimmer, warmer, longer wavelength bulbs with red, yellow and orange color spectrums (think: campfire) at dusk—which boosts melatonin. You can also go high-tech with LED tunable lights that automatically adjust day and night light color temperature and brightness levels.
Circadian lighting was a $400 million market in 2017; it is estimated to be $4 billion by 2024.
What’s Next for Circadian Health?
A future development that will revolutionize medicine and wellness is the ability to measure people’s unique, precise circadian clock state in real-time, maybe even from a single blood, urine, saliva or breath sample at the doctor’s office or at home. A single sample will be able to measure dozens (or even hundreds) of biomarkers at once to pinpoint exactly what our internal circadian time is.
The possibility of a circadian “fingerprint” measurement has serious implications for the timing of medicine because when you take different medicines, have surgery or chemo, and what lab tests reveal, depend so much on where you’re at in your circadian clock.