SLEEP is THE most important thing in life other than oxygen and water. We can go for a month with no food - and we can live a long time on a poor diet. Heck, we can go a lifetime without exercise. But we can only survive without sleep for seven days! Proper sleep (we recommend 8 hrs) is necessary for optimal health. If you have a perfect diet and workout routine, but only sleep for a few hours each night, you will not be healthy.
OUR HERITAGE AND SLEEP CYCLES
We evolved to have a sleep-wake cycle entrained to the sun. The sun's rays in the morning gave a cue to our ancestors that it was time to get up and start looking for food. Just like every other organism on the planet, we have a built-in twenty-four hour natural cycle - or Circadian Rhythm. Our brains have an area called the Suprachiasmatic nucleus that helps regulate these cycles. This small area is very sensitive to certain natural cues called Zeitgebers.
WHAT IS A ZEITGEBER?
These “time givers” are external cues that tell our body that it is time to sleep or wake and can include:
Light – Our bodies expect daytime to include the full spectrum of light from infrared to near ultraviolet. Blue light is a big part of daylight. Sunrise and sunset are characterized by more red-orange colors. We and all other living organisms on Earth have been genetically programmed to expect this pattern. It’s interesting to note that since humans tamed fire for 1.5 million years, we have developed an ability to receive red-orange light at night and stay entrained to our normal circadian rhythm.
Heat – Our bodies are programmed to expect warmer temperatures during the day and cooler temperatures at night.
Social Interactions/exercise/eating or drinking patterns – We are wired to “wind down” before rest. When these activities are thrown in the mix close to bedtime our rhythms can be disrupted.
Due to the change of seasons and length of day (photo period), the sun rises and sets at different times every day and Zeitgebers aim to keep us on the sun's schedule. As the days lengthen and warm in the summer, our bodies naturally want to get up earlier each day. In winter when there is less light and it is cooler, we want to get up later and go to sleep earlier. Unfortunately the hectic schedule of our modern society can make it difficult to listen to these cues, interfering with our natural rhythms.
HOW DO HORMONES FACTOR IN? So what do hormones have to do with our sleep cycle? Well, while the basic formula for sleep is complex, in a nutshell, the hormone link boils down to two - cortisol and melatonin. Our "stress" hormone - cortisol - is supposed to be at its lowest level at night. Our "relaxation" hormone - melatonin (made from serotonin) - spikes when it gets dark. This window of low cortisol and high melatonin is our clue to rest, relax and fall asleep. During the night, cortisol rises to prepare our body for the morning. It has an adrenalin-like effect causing a rise in heart and breathing rates, temperature, and alertness. Throw in our natural alarm clock - the sun - and boom, we wake up.
STRESS can be an issue in sleep because it raises cortisol to high levels, closing the nightly window of low cortisol and high melatonin.
IMPROVING YOUR SLEEP
While it may not be possible in a world with 9 to 5 jobs to rise and rest based with the sun as our ancestors did, there are many things you can do to help your sleep patterns
Maximize Blue light during the day – Sunshine provides us with blue light, but many of us never go outside due to work commitments. It would be wise to try to get some exposure at lunch or break to establish the normal photoperiod and produce vitamin D.
And avoid it at night. The electronics we use like TV's, computers, lights and cell phones bombard us with blue light. We realize it may be difficult to avoid these; so turning off lights and gadgets one hour prior to bed can be a big help. Blue blocker glasses for night can be an invaluable tool and our easy to purchase online . There are also several programs and apps that can remove the blue from electronic screens. f.lux has a free version for mac and windows. Finally if you must have light, make it red-orange (remember fire). Consider using red lights in some of your lamps.
Have an established routine – Variations in times and amount of sleep can wreak havoc on your rhythms. Have a set relaxation window at least one hour before bed. Additionally, try to go to bed and rise at the same time each day.
Lower your thermostat at bedtime – Studies have shown that the optimal sleeping temperature can range between 60 – 68 Degrees Fahrenheit. Experiment and find the temperature that is right for you.
Minimize nighttime activity - Whether mental or physical, activity can be disruptive, so get in the habit of winding down at least an hour prior to your bedtime.
Avoid Caffeine – and other stimulants after noon that block sleep-inducing chemicals in the brain and produce adrenaline.
Consider a natural sleep aid – like Chamomile or Valerian root tea, Melatonin or Chelated Magnesium. Consult your MD, Naturopath or Nutritionist for help in determining your correct dosage.
Use a “natural” alarm to help maintain your rhythm. Try a dawn simulator - these timers slowly turn up the light to mimic the sunrise and are easy to find on the web. Or, you can also download apps that can wake you up with chirping birds and other pleasant sounds. Check out this article for some options - 5 sleep apps to get you more and better rest.