Sleep Deprivation: As Damaging To Brain Health As Binge Drinking?
Dr. Farrell Cahill, PhD. Head of Research, Medisys Health Group
In our January issue we talked about the eight proactive things you could do to improve brain health and ward off cognitive decline – at the top of the list were sleep and exercise. If you are like many Canadians, you’re getting less than six hours of sleep per night. The cumulative health consequences of sleep deprivation are severe – including increased risk of hypertension, diabetes, obesity, depression, heart attack, and stroke1. Sleep deprivation negatively impacts the whole body, but as Dr. Adrian Owen explains, no one organ is as severely affected as the brain.
Recent reports suggest that about 1 in 3 Canadians are chronically sleep deprived including adolescence and children, making Canada the 3rd most sleep deprived country on the planet! Not only is sleep deprivation having a devastating impact on our health, some report suggests that sleep deprivation is also costing the Canadian economy about $21.4 billion (USD) per year due to lost employee productivity.
Sleep deprivation has long been associated with acute cognitive impairment; however, more recent findings suggest that both the acute and long-term health implications of sleep deprivation are even broader and more complex than initially believed. Poor sleep habits have been linked to everything from mental and emotional health issues, to weakened immunity, to increased risk of obesity. When it comes to weight management, sleep is an important hemostatic modulator and the reduction of sleep has been shown to significantly decrease both glucose and fat metabolism while also inappropriately increasing appetite2,3, leading to weight gain. “Sleep plays an important role in regulating the hormones that influence hunger (ghrelin, cortisol, and leptin),” explains Medisys Registered Dietitian Richelle Tabelon, “that’s why sleep deprivation increases appetite and lads to overeating and weight gain” Tabelon continues. Regular exercise and maintaining a healthy diet will always be important components of weight maintenance – but if you are growing out of your clothes and can’t figure out why, it might be time start getting to bed earlier.
If the prospect of a weakened immune system, mental health disturbances, and increased risk of weight gain, heart disease, and type II diabetes doesn’t make you want to get to bed earlier consider this: driving while sleep deprived (the norm for up to 30% of us) is the cognitive impairment equivalent of drunk driving.
Imagine this scenario: You wake up at 5:30am to get an early start on the day because you have a busy week at work. You work until 8pm to meet a deadline and then catch up with a friend for a bite to eat before driving home. It’s 10:30pm and you have now been awake for 18 hours. Sound familiar? You are about to get behind the wheel, and even without one sip of alcohol you are, from a cognitive impairment perspective, intoxicated4. After just one more hour of being awake, 11:30pm in this case, your cognitive performance would be as impaired as someone with a blood alcohol level of 0.1%. That’s equivalent to an average weight adult male consuming 5-6 drinks (assuming the Canadian standard of 13.6 grams of alcohol per drink). The cognitive impairment effects of long periods of wakefulness and alcohol consumption are cumulative – add even a small glass of wine or beer to the above scenario and by getting behind the wheel you are engaging in extremely risky behaviour.
Research on sleep and cognition has shown that engaging in any cognitively demanding task while sleep deprived is risky – be it a physical like operating a vehicle, or an intellectual one like business-critical decision making (recall the Challenger explosion blamed on certain launch managers having had only two hours of sleep the night previous). Dr. Adrian Owen, a neuroscientist at Western University and the Chief Scientific Officer of Cambridge Brain Sciences — a leading online brain health platform — has been studying the effects of sleep deprivation on the brain. Dr. Owen is soon launching the World’s Largest Sleep Study in order to better understand the connection between brain health and healthy sleep. In an exclusive interview with Medisys, Dr. Owen sat with us to answer some of our burning questions about sleep health and the medical impact of sleep deprivation.
Q: What happens to our brains when we don’t get enough sleep?
A: We’ve long known that sleep deprivation negatively impacts alertness and reaction times, but a more recent studies5 have concluded that a wider range of brain functions are disrupted by sleep loss, including attention, working memory, and emotional processing. The brain becomes less stable the longer you are awake, diminishing your ability to focus your cognitive resources where they are needed. One study6 scanned the brains of people at rest (but not asleep), and could, with very high accuracy, predict which brains were sleep-deprived and which were not. Interestingly, the sleep-deprived individuals had less overall connectivity between active areas. In other words, researchers could pick out a sleep-deprived individual just by looking at their brain activity at rest – suggesting sleep deprivation causes physiological changes in the brain!
Q: How do you define sleep deprivation and how common is it?
A: Most adults need between 7-9 hours of sleep per night. Teenagers and children need more sleep due to their stage of growth and development – especially brain development, and older adults (65+) need a little less sleep (7-8 hours per night). Sleep deprivation is, unfortunately, very common in Canada – it’s estimated that about 30% of Canadian adults get fewer than 6 hours of sleep per night. In today’s business world, technology allows for many work tasks to be completed anywhere, at any time, using any device. Because of this, there is often pressure – whether it’s real or perceived – for people to put in as many hours of work as possible, even if it means less sleep. In certain professions such as medicine, financial services, legal professions, law enforcement, and aviation, long periods of wakefulness are often requirements of the job. In many cases, there are laws governing required rest times between shifts to protect both the worker and the public. However in some professions, such as medicine, 24 hour or longer shifts are not uncommon – which is particularly concerning from a public health perspective in light of mounting evidence that just 18 hours of wakefulness results in cognitive impairment equivalent to alcohol intoxication. Regardless of the profession, more and more Canadian adults are working longer hours and sleeping less during the week – and don’t be fooled into thinking that a few ‘catch up sleep’ hours on the weekends are going to make up for the loss. From a neurological perspective, when you lose sleep, consider it gone forever.
Q: What’s the impact of sleep deprivation on Canadian businesses?
A: Sleep deprivation results in increased risk of workplace accidents and injury. The Association of Workers’ Compensation Boards of Canada (AWCBC) reported 852 workplace deaths in 2015 alone, in addition to the hundreds of thousands of claims processed every year for work-related injuries. Some of the more infamous workplace accidents linked to sleep deprivation include Chernobyl, the Exxon Valdez Oil Spill, and the nuclear incident at Three Mile Island.
Employers may be inclined to reward or encourage an employee who puts in extra hours to meet a deadline. However, even a single long day at work can significantly impair an employee’s judgment, attention, reaction times, vigilance, and working memory7 – putting both the employee and the company at risk. This disrupted cognition due to sleep deprivation adds up over time and leads to widespread reductions in workplace productivity as well as increased risk of errors, omissions and workplace accidents and injuries. One survey8 of four U.S. companies in various industries found that workers with poor sleep habits were less able to perform work tasks over time, costing the organization thousands of dollars per employee annually in productivity losses. Evidence suggests that inadequate sleep results in a 162% greater chance of a work-related injury9 and a significantly increased risk of motor vehicle crashes10.
It’s important to note that working while sleep deprived isn’t only hazardous within safety sensitive environments. Any executive accountable for business-critical decisions puts the company at risk if making these decisions while sleep deprived.
A word to the wise: If you know a member of your team worked late to complete a project, don’t give them a bonus, give them a morning off to sleep in!
Q: What can I do to prevent sleep deprivation?
A: Researchers have identified a number of habits that support better sleep. All which should be tried before turning to over-the-counter sleep medication. Healthy sleep habits include:
- Exercising regularly during the day. Physical activity during the day has beneficial effects on sleep the night after, and promotes better sleep as a consistent long-term habit11.
- Reducing stress. Engage in stress-relieving activities including yoga, meditation, warm baths or other activities that help you unwind.
- Avoiding caffeine. Limit caffeine and avoid other sleep disruptors like nicotine (in case you needed another reason to quit), and avoid heavy meals close to bed time.
- Drinking in moderation. Alcohol negatively impacts sleep quality. Alcoholic beverage consumption should be limited to a maximum of 7-9 drinks per week for women and 14 drinks per week for men, not exceeding 1-2 drinks daily (no, you can’t save them up for weekends like Weight Watchers points!). A “drink” is considered to be 12 ounces (341 ml) of beer, 5 ounces (142ml) of wine or 1.5 ounces (43 ml) of spirits.
- Modifying your bedroom environment. Make your bedroom a sleep sanctuary by eliminating light, noise, and excessive heat and by turning off electronic devices before bedtime.
- Not forcing it. If you’re lying awake and sleep just isn’t happening, get out of bed and do something else until you’re tired again.
- Keeping a consistent sleep schedule. Staying up later on weekends can throw off your biological clock and make it harder to sleep well during the rest of the week.
- Making sleep a priority. There will only ever be 24 hours in a day. Between making time to exercise (which is very important), your career, family, spending time with friends, running errands, and working your way through that ever-growing ‘to-do’ list, the only surefire way to get enough sleep is to make it a priority. Set a bet time and stick to it – no ifs, ands, or buts.
Not surprisingly, one of the biggest predictors of healthy sleep habits in adults is healthy sleep habits as a child. If you are a parent or grandparent – set a positive example and encourage the whole family to make sleep a priority!
For more advice on “sleep hygiene,” Harvard’s Division of Sleep Medicine has twelve simple tips to start with.
Q: What’s the next step in learning about how sleep affects the brain?
A: There is still a lot to learn when it comes to sleep and cognition. Despite the mounting body of research linking sleep and brain health, there is still much debate over the details. That’s why we are using the Cambridge Brain Sciences platform to launch The World’s Largest Sleep Study. It’s an unprecedented look at the sleep habits of people all over the world. Through this study we hope to answer some of the most debated questions such as which facet of cognition is most impaired by sleep loss, how much sleep is needed to avoid cognitive impairment, and which professions get the least sleep. We’re hoping through this study we’ll learn everything we need to know so that we can finally put this great debate to bed.
- Morselli L, Leproult R, Balbo M, Spiegel K. Role of sleep duration in the regulation of glucose metabolism and appetite. Best Pract Res Clin Endocrinol Metab. 2010;24:687–702.
- Knutson KL. Sleep duration and cardiometabolic risk: a review of the epidemiologic evidence. Best Pract Res Clin Endocrinol Metab. 2010;24:731–743.
- Williamson, A. M., & Feyer, A. M. (2000). Moderate sleep deprivation produces impairments in cognition and motor performance equivalent to legally prescribed levels of alcohol intoxication. Occupational & Environmental Medicine, 57, 649-655.
- Krause, A. J., Simon, E. B., Mander, B. A., Greer, S. M., Saletin, J. M., Goldstein-Piekarski, A. N., Walker, M. P. (2017). The sleep-deprived human brain. Nature Reviews Neuroscience. doi: 10.1038/nrn.2017.55
- Kaufmann, T., Elvsåshagen, T., Alnæs, D., Zak, N., Pedersen, P., Norbom, L. B., Quraishi, S. H., Tagliazucchi, E., Laufs, H., Bjørnerud, A., Malt, U.F., Andreassen, O.A., Roussos, E., Duff, E. P., Smith, S. M., Groote, I. R., & Westlye, L. T. (2016). The brain functional connectome is robustly altered by lack of sleep. Neuroimage, 127, 324-332.
- Lim & Dinges
- Rosekind, M. R., Gregory, K. B., Mallis, M. M., Brandt, S. L., Seal, B., & Lerner, D. (2010). The cost of poor sleep: workplace productivity loss and associated costs. Journal of Occupational and Environmental Medicine, 52, 91-98.
- Uehli, K., Mehta, A. J., Miedinger, D., Hug, K., Schindler, C., Holsboer-Trachsler, E., Leuppi, J. D., & Kunzil, N. (2014). Sleep problems and work injuries: A systematic review and meta-analysis. Sleep Medicine Reviews, 18, 61-73.
- Barger, L. K., Cade, B. E., Ayas, N. T., Cronin, J. W., Rosner, B., Speizer, F. E., & Czeisler, C. A. (2005). Extended work shifts and the risk of motor vehicle crashes among interns. New England Journal of Medicine, 352, 125-134.
- Kredlow, M. A., Capozzoli, M. C., Hearon, B. A., Calkins, A. W., & Otto, M. W. (2015). The effects of physical activity on sleep: A meta-analytic review. Journal of Behavioral Medicine. doi: 10.1007/s10865-015-9617-6