“If we don’t continue to chip away at our collective delusion that burnout is the price we must pay for success, we’ll never be able to restore sleep to its rightful place in our lives,” Arianna Huffington, author of The Sleep Revolution.

Over recent years, sleep has become a widely discussed topic - or more so the lack of it. In 2017, a report¹ found that 67% of UK adults suffer from disrupted sleep and this is likely to have worsened since the outbreak of COVID-19. As much as we are a society who now more than ever invest on our health and wellbeing, sleep seems to be, well, slept on. Even though we now know that sleep is at the very heart of our physical and mental health.

The question is, when it comes to sleep, why do we actually need it? What is affecting our sleep quality and what steps should we take to improve it? 

Why do we need sleep? 

Sleep is something that we all do. It’s something that allmammals do. It’s even observed in birds, reptiles, some fish and in some kind of form, insects. As a phenomenon so widely adopted by organisms on this earth, it must be pretty important.

To put it simply, sleep is essential. Scientists used to believe we were physically and mentally inactive while we sleep, but we're far from it. We now know that sleep is one of nature’s ways of improving our mental and physical performance, helping us become better versions of ourselves.

In terms of cognitive function:

• Our important memories are strengthened during sleep, whilst unimportant ones are trimmed back to free up capacity for new learning².
• Our emotions are reset every night, allowing us to face the world with a clearer, more refreshed outlook the next morning.
• In terms of physical health, we are constantly improving our immune system while we sleep, strengthening our natural killer cells against foreign invaders (viruses included)³.
• Growth hormones are produced, promoting the growth and repair of damaged cells and stress hormones return to low levels during this time too³. This might explain why those suffering from insomnia are twice more likely to develop mental health issues, like anxiety and depression⁵.

What’s more, there is now a growing body of research supporting the association of lack of and low-quality sleep with certain health risks, including weight gain, obesity, diabetes, heart disease and cognitive decline^6,7,8. 

How long should I be sleeping for?

Scoring high on the sleep board doesn’t always mean getting as much sleep as you can. In fact, sleeping too long can often be a sign of an underlying illness like depression⁹. The most important measure of your sleep is how you feel during the day. The vast majority of people need around 7-9 hours of sleep every night, however, there exists some individual variation, so it’s difficult to judge by the length of your slumber.

How can I judge my sleep quality?

Try to hone in on your energy levels when you’re awake. Do you need caffeine to keep you going throughout the day? Do you find yourself catching up on sleep every weekend? If so, it may be worth re-evaluating some of the routines surrounding your sleep. 

I'm tired, so why can't I fall asleep?

 A lack of routine is often a big culprit when experiencing difficulty falling asleep. Our internal body clock, known as the circadian rhythm, runs on a 24-hour cycle and has an innate appreciation for routine. Once you establish a more regular pattern of sleeping, your body will improve its ability to anticipate sleep at night, and consequently release the ‘sleep’ hormone melatonin. Interestingly, your brain isn’t fond of irregularity either. Uncertainty can cause spikes in your levels of stress hormones, like cortisol, which is why it’s beneficial to create a familiar routine that will help you wind down and relax before bed. Have a go at lighting some candles, enjoying a warm bath and having a little stretch before you hit the hay. 

How can I improve my sleep environment?

The second most powerful signal to your body clock is light. Natural light has a much greater influence on your body than electric light, so if you are feeling fatigued during the day it’s always worth picking yourself up and taking a short walk outside to help you feel more alert. If you are working from home, try setting up next to a window to get as much natural light stimulation as you can. Although not as strong, electric light still has an impact on your body clock in the evening, with blue light repressing the release of melatonin. Try to keep technology out of the bedroom if you can and switch off your phone an hour before you are planning to sleep. Phones are highly arousing and are designed to feed our craving brains with new information. How about challenging yourself tonight and leaving your phone out of the bedroom? Out of sight, out of mind. 

Can my diet help me sleep?

Nutrition can also influence our sleep health and the quality of sleep that we get. A Mediterranean style diet, high in vegetables, fruits, legumes, grains and unsaturated fats such as olive oil, tends to associate itself with better quality sleep. Lab studies have also found that meals high in protein and fibre are linked with improved sleep than meals high in saturated fat¹⁰. This comes as no surprise to us, as a good diet can support all pillars of health, including the microbiome, inflammation, mood and consequently, sleep. On the other hand, alcohol and caffeine are known to affect our sleep quality, often without us even realising. The optimum cut-off time for caffeine consumption is said to be around 6 hours before your bedtime, although this varies between individuals depending on how quickly they can metabolise it. Nevertheless, research has found that caffeine can still disrupt deep sleep, even at this cut-off time, and is associated with micro-arousals (waking up for short periods in the middle of the night)¹¹. If you think your caffeine intake is affecting your sleep, try to limit your coffee intake to the morning.

Final Thoughts 

Good quality sleep could be the answer to so many of our health-related questions, so why not pay a little extra attention to your sleep hygiene? It seems like a win-win in terms of mental health, productivity and physical health. Give some of the suggestions in this article a try, we wish you luck on your journey to better sleep.

How can I get started?

Why not take our quiz and see which vitamins we can provide you with to improve your sleep? Additionally, with every subscription you receive a free consultation with your very own nutritionist, who can help you build a diet that aid's better sleep. Take our quick online quiz here to get started, or email our senior nutritionist nuna@personalised.co

References

1. The Wellbeing Report from Aviva, 2017 

2. Aude Jegou, Manuel Schabus, Olivia Gosseries, Brigitte Dahmen, Geneviève Albouy, Martin Desseilles, Virginie Sterpenich, Christophe Phillips, Pierre Maquet, Christophe Grova, Thien Thanh Dang-Vu. Cortical reactivations during sleep spindles following declarative learning. NeuroImage, 2019; 195: 104 DOI: 10.1016/j.neuroimage.2019.03.051

3. Irwin M, McClintick J, Costlow C, Fortner M, White J, Gillin JC. Partial night sleep deprivation reduces natural killer and cellular immune responses in humans. FASEB J. 1996 Apr;10(5):643-53. doi: 10.1096/fasebj.10.5.8621064. PMID: 8621064.

4. Kim, T. W., Jeong, J. H., & Hong, S. C. (2015). The impact of sleep and circadian disturbance on hormones and metabolism. International journal of endocrinology, 2015, 591729. https://doi.org/10.1155/2015/591729

5. Khurshid KA. Comorbid Insomnia and Psychiatric Disorders: An Update. Innov Clin Neurosci. 2018;15(3-4):28-32.

6. Knutson KL, Ryden AM, Mander VA, Van Cauter E. Role of sleep duration and quality in the risk and severity of type 2 diabetes mellitus. Arch Intern Med 2006;166:1768–1764.

7. Kasasbeh E, Chi DS, Krishnaswamy G. Inflammatory aspects of sleep apnea and their cardiovascular consequences. South Med J 2006;99:58–67.

8. Taheri S. The link between short sleep duration and obesity: We should recommend more sleep to prevent obesity. Arch Dis Child 2006;91:881–884.

9. National Sleep Foundation: "The Ill Effects of Too Much Sleep.”

10.  St-Onge MP, Mikic A, Pietrolungo CE. Effects of Diet on Sleep Quality. Adv Nutr. 2016;7(5):938-949. Published 2016 Sep 15. doi:10.3945/an.116.012336

11. Drake, C., Roehrs, T., Shambroom, J., & Roth, T. (2013). Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. Journal of clinical sleep medicine, 9(11), 1195–1200. https://doi.org/10.5664/jcsm.3170