We vastly underrate this important aspect of our lives. I was previously one of those folks who thought it was impressive that I could get by on just 4 hours of sleep each night. Little did I know how much damage I was doing to my body, and the adverse impact that this was having on my brain specifically. Research has shown that most adults need about 7-8 hours of sleep per night,1 and one Japanese study showed that the risk of stroke increased by 50% in those who slept for either 6 hours or less, or 10 hours of sleep or more, when compared to folks who slept for 7 hours.2 Depression and other health conditions have been similarly linked to abnormal sleep levels.
Melatonin
Sleep is hugely important to our health, as it generates melatonin, which plays a critical role in our immune system. Have you ever wondered why you got sick after a few sleepless nights? Melatonin is a powerful intramitochondrial (the powerhouse of the cell) antioxidant, and your body makes this naturally as you sleep. Think of melatonin as putting your cancer cells to bed at night, as that is essentially what it does.3 The only way we can generate melatonin is through sleep, and the only food that we eat that can inhibit melatonin generation is – wait for it – meat.4
How can we get/make this?
Though they are occasionally necessary (vitamin D and vitamin B12 come to mind) I am generally no fan of supplements, and here is a classic reason why: 70% of the melatonin supplements on the market are shown to not contain what is on the label.5 They have too much melatonin, too little, or even no melatonin at all. And then most melatonin supplements are between 3 and 60 times the amount that your brain generates naturally, and we have no way of telling whether that is safe or not. So as always, better (and less expensive!) to stick with whole foods than to supplement!
I will have to do another article to elaborate on just a few of sleep’s benefits, so in the meantime let’s just concentrate on the areas that we can change to improve our sleep, thus improving our immune systems.
When trying to improve sleep:
Caffeine
Eliminate all caffeine – even morning coffee. We become more sensitive to caffeine as we age, and so the fact that we used to be able to drink coffee throughout the day is no guarantee that this can be done as we age. Even as little as one cup of coffee at night has been shown to cause significant adverse effects on sleep.6 So if there are any sleep issues at all, that is the first place I look.
Alcohol
Eliminate all alcohol. There is nothing good about alcohol. It is full of sugar and doesn’t exactly aid in good decision making. It destroys sleep. There are myriad adverse impacts that alcohol has on sleep. Most can quit this cold turkey. Talk to me if you have a concern about doing this.
Blue Light
This delays the normal bedtime melatonin surge by about 45 minutes, so get rid of all blue light sources about an hour prior to your planned bedtime. This includes smart phones, laptops, Kindles, TVs, etc. Get an old-fashioned paper book, or better yet, have no book at all, and only go to bed when tired! Also, cell phones have been shown to disturb sleep independently of blue light, so this is just another reason to keep those phones out of the bedroom!
Bedroom = cave
Your bedroom should resemble a cold, dark cave.7 If light leaks are an issue, consider using an eye mask. I use this and it helps greatly. Sleep is exquisitely sensitive to temperature8 and the ideal temperature for sleep is 65F, which is likely a bit cooler than most of us are keeping our bedrooms.9
Quiet
Even at low levels, noise is significantly correlated with poor sleep, and the louder the noise, the poorer the quality of sleep.10 So it may be worth investing in some ear plugs. I use the soft, trumpet-shaped ones as I feel they expand and block out sound the best. I live downtown, and with all the sirens and other city noise, would never be able to sleep without them.
Clean linens.
I could not find any studies to back this up, but don’t we all love the smell of linens fresh from the drier? Though it may not be included on PubMed (the go-to for medical research), it is part of professional sleep coach Nick Littlehale’s regimen, which he details in his fantastic book “Sleep.” Part of his sleep “system” or plan for his athletes is that they have fresh linens each night. He would not do this if it didn’t help.
Stick to a routine
Keeping similar bedtime and awakening times for both weekdays and weekends will help the body assimilate to a sleeping routine greatly. Once you have been doing this for a bit you may find that you do not even need an alarm to wake – the body has learned what it needs to function. We just need to listen.
Big Picture
Sleep plays an enormous role in our health and how we are able to interact with others. We neglect its importance at our peril. Start thinking of your sleep as a component of your health, and your bedroom as your “recovery chamber” as that is what it can and should be!
References:
- Leng Y, Cappuccio FP, Wainwright NW, et al. Sleep duration and the risk of fatal and nonfatal stroke: a prospective study and meta-analysis. Neurology 2015;84(11):1072-9.
- Fang J, Wheaton AG, Ayala C. Sleep disturbance and history of stroke among adults from the USA. J Sleep Res. 2014;23(5):331-7.
- Blask DE, Dauchy RT, Sauer LA. Putting cancer to sleep at night: the neuroendocrine/circadian melatonin signal. Endocrine. 2005 Jul;27(2):179-88.
- Schernhammer ES, Feskanich D, Niu C, Dopfel R, Holmes MD, Hankinson SE. Dietary correlates of urinary 6-sulfatoxymelatonin concentrations in the Nurses’ Health Study cohorts. Am J Clin Nutr. 2009 Oct;90(4):975-85.
- Erland LA, Saxena PK. Melatonin Natural Health Products and Supplements: Presence of Serotonin and Significant Variability of Melatonin Content. J Clin Sleep Med. 2017 Feb 15;13(2):275-281. doi: 10.5664/jcsm.6462. PMID: 27855744; PMCID: PMC5263083.
- Loret-Linares C, Lafuente-Lafuente C, Chassany O, et al. Does a single cup of coffee at dinner alter the sleep? A controlled, crossover, randomized trial in real-life conditions. Nutrition & Dietetics. 2012;69(4):250-5.
- Brown TM, Brainard GC, Cajochen C, et al. Recommendations for daytime, evening, and nighttime indoor light exposure to best support physiology, sleep, and wakefulness in healthy adults. PLoS Biol. 2022;20(3):e3001571.
- Yan Y, Zhang H, Kang M, Lan L, Wang Z, Lin Y. Experimental study of the negative effects of raised bedroom temperature and reduced ventilation on the sleep quality of elderly subjects. Indoor Air. 2022;32(11):e13159.
- https://www.healthline.com/health/sleep/best-temperature-to-sleep#the-science (Accessed 5/31/23).
- Smith MG, Cordoza M, Basner M. Environmental Noise and Effects on Sleep: An Update to the WHO Systematic Review and Meta-Analysis. Environ Health Perspect. 2022 Jul;130(7):76001.