Sleep is so vital for good health, but it is often overlooked and undervalued. In addition to better immune function, sleep is the time when we clear accumulated toxins from our brains, when we consolidate memory, and when we upregulate the brain’s executive function. No wonder we can’t think straight and feel lousy when we have a bad night’s sleep!
Let’s talk about some of the many things you can do to get a good, deep sleep:
Sleep in complete darkness. Blackout blinds are a good investment for better sleep, and better health! Also, remove bright digital display alarm clocks or any other source of light in your bedroom. If you get up to urinate at night, use a dim nightlight in the bathroom instead of turning on the light.
When light hits the eyes, it disrupts the circadian (daily) rhythm of the pineal gland and inhibits the production of melatonin. Melatonin is called the sleep hormone, since one of its roles is to induce drowsiness. Yellow light, like the light of a candle or a campfire, does not trigger this response. Think about sitting around a fire at a campsite, then rolling into your sleeping bag and having a deep refreshing sleep. Many of us have had this experience.
On the other hand, blue light (think sunny morning with a blue sky) increases serotonin and activates alertness. This is great to get going in the morning, and we always recommend a morning walk outdoors for people who are trying to retrain their circadian rhythm.
However, are you in front of an electronic screen at night? Screens from computers, TVs and even cellphones beam blue light right in our faces, tricking the brain into thinking it is day instead of night. To fall asleep easily, either turn off electronics, or at least block blue light with a filter, for two hours before sleep.
Speaking of circadian rhythm, if you are a night owl, try dialing back your bedtime, thirty minutes at a time. The adrenal glands, our stress management system, do the majority or their recharging between the hours of 11pm and 1am. In this same window, the gallbladder is busy dumping toxins into the intestine for elimination in the morning. If you are awake during this window, these important processes are not going to work as well as they should. Our great-grandparents, prior to the widespread use of electricity, would spend an hour or two in candlelight after sundown, and then go to bed. Nature intended us to follow this circadian pattern.
Avoid eating after dinner. Have you heard of Brain-derived Neurotrophic Factor? You can think of it as “Miracle-gro” for your brain, increasing and repairing neural connections. This is secreted during sleep, and fasting stimulates its secretion. Ideally, we should allow at least a four-hour window between dinner and bedtime, with no snacking after our evening meal, for better sleep, better digestion, and less inflammation in the body.
Evening snacks are often sugary, salty, and carb-laden. Not only can they raise your blood sugar and inhibit sleep, but a few hours later they can cause a blood sugar drop (hypoglycemia) which the body perceives as a stressor, waking you up in the middle of the night.
And what about caffeine? Besides melatonin, there is a second mechanism that induces sleep, which is the accumulation of a biochemical called adenosine during our waking hours. Adenosine exists in all cells of the body and is necessary for energy transfer between cells. When adenosine builds up in the brain, it induces a feeling of drowsiness, which keeps increasing until we sleep. During sleep, adenosine is cleared out by the glymphatic system. This buildup of adenosine is called sleep pressure, and if you have ever stayed up for hours past your bedtime, you know the feeling: barely able to resist falling asleep.
It turns out caffeine blocks the action of adenosine and removes this “sleep pressure”. Some of us are very efficient at metabolizing caffeine and break it down almost as soon as it gets into the circulation. This is the person who can enjoy a cup of coffee right before bed, then sleep like a baby. Other people break down caffeine very slowly, so the caffeine in that afternoon cup of coffee is still in the brain, blocking adenosine and keeping us awake. For those poor sleepers who are slow metabolizers of caffeine, we recommend avoiding coffee, tea, cola and even chocolate, especially after lunch and beyond.
Alcohol doesn’t help, either. Although alcohol can make you feel relaxed and even drowsy, this effect is short-lived. After a couple of drinks, many people report waking at 3am, feeling hot, irritated and wide awake. This seems particularly true for perimenopausal women. Interestingly, 3am is “liver time” according to the Chinese Medicine body clock, so the extra burden alcohol places on the liver is making itself apparent.
Even if that nightcap doesn’t wake you up, alcohol can impair the deeper stages of sleep, when the brain and body do much of their healing and repair.
Pay attention to temperature. The adage “warm bed, cold room” is true! First, consider a hot bath or shower before bed. Warm water will bring circulation to the skin (pink and rosy after a bath), which then cools the body and makes us relaxed.
But we need to feel comfortable during sleep, which is why we seek our warm cozy bed. A cool head, from our cool room, improves sleep, but cold feet can wake us up. A study has shown that wearing socks to bed can reduce nighttime waking.
We spend one third of our life asleep. Good sleep is an important foundation of health, just like diet and exercise. There are so many things we can do to enhance our sleep. Paying attention to these things can make every day more productive and more enjoyable.
Want to learn more about the vital function of sleep? We recommend “Why We Sleep” by the neurophysiologist Matthew Walker. It’s a fascinating read!