Sleep is generally undervalued by society today, and yet for good health and longevity, sleep should be a priority. Research shows that even short-term sleep deprivation causes increased levels of the stress hormone cortisol, raises blood pressure, impairs our body’s ability to regulate blood sugar and activates our sympathetic nervous system which can make us feel irritable and stressed. Furthermore, failure to remain alert during the day is a major cause of accidents, including road traffic and occupational accidents, leading to thousands of deaths a year. (1)
Sleep needs are individual; our overall health, daily activities and lifestyle all contribute to our ideal length of nightly sleep. Different life stages also demand different sleep patterns: toddlers benefit from 11-14 hours of sleep; children of Primary school age 9-12 hours; teenagers 8-10 hours and adults 7 hours or more. (2) Quality of sleep is important; if you are not waking refreshed then it is time to take action to improve your sleep.
Hormones play a vital role in our sleep.
Melatonin is a hormone, produced in the pineal gland, which regulates sleep and helps to set the body’s internal biological clock. Melatonin is a potent antioxidant and functions as an anti-inflammatory, which highlights the importance of 7 to 9 hours of sleep for adults every night, for our overall health and wellness. Our body repairs itself whilst we sleep so keeping inflammation down and reducing the chance of chronic disease including Alzheimer’s disease and dementia.
Melatonin levels can drop in those who have irregular sleep patterns and perhaps work night shifts and those who are jet lagged. All other hormones are supported by good sleep and in particular the hormones leptin for fullness after eating and ghrelin, which stimulates hunger, are balanced when we get enough sleep, so we make better food choices during the day. To make melatonin the body needs enough serotonin.
Serotonin, known as 5-HT, is a neurotransmitter and also acts as a hormone. Often referred to as the ‘happy hormone’ because it influences our mood, it is probably less known for the role it plays in the regulation of appetite, digestion, sleep, sexual behaviour, body temperature, learning and memory. Insufficient serotonin is thought to play a role in anxiety, depression, mania and other health conditions.
Most of the serotonin found in the body is in the gut – between 80%- 90% of serotonin is found in the cells lining the gastrointestinal tract. (2) Good gut health is vital for the production of serotonin. Serotonin is made from the essential amino acid tryptophan; it can’t be made by your body so must be obtained from the foods we eat. Salmon, eggs, cheese, turkey, tofu, pineapple, nuts, seeds and oats are good sources of tryptophan.
Regular exercise is known to increase serotonin levels and so help sleep. Thirty minutes of aerobic exercise five times a week plus two strength-training sessions per week can improve mood disorders and heart health. (3) Exposure to sunlight increases serotonin levels and promotes health-boosting vitamin D production.
Nutrition can have a big impact on how well you sleep.
Eating a whole food diet, which provides the nutrition the body needs, helps sleep; it influences being able to get off to sleep easily, staying asleep and having a good quantity and quality of sleep. In contrast, eating a diet high in unhealthy fat, sugars, and refined carbohydrates is linked to increased insulin levels, which in turn, can impact your melatonin levels.
Poor diet → increased insulin → reduced melatonin → lack of sleep → increased insulin.
Anything that has a stimulant effect can keep you awake including caffeine and chocolate and of course the closer to bedtime, the worse the effect. For most people, it may be better not to have any caffeine after midday. Enjoy a calming herbal tea, such as chamomile, instead.
Alcohol can also change our sleep pattern meaning less deep sleep and more disruptions. This can promote low mood, increased stress and tiredness the next day. Alcohol acts as a diuretic which might mean having to pass urine in the night, so disrupting sleep.
Top Tips for great sleep
Magnesium is a key nutrient to aid sleep. Try including almonds, cashews, dark chocolate, avocado, black beans and other legumes, pumpkin seeds, oats, bananas, kale and spinach in your diet for top sources of this vital nutrient.
Review and reduce your consumption of artificial sweeteners, including aspartame, which may be contributing to any sleep problems.
Reishi mushroom, consumed as a powder, tea or capsule, may have a mildly sedative effect, calm the nervous system and aid restful sleep.
Start the day with a 15-20 minute walk to reset your circadian rhythm and benefit from important exercise and vitamin D. For maximum benefit avoid wearing sunglasses at this time.
Avoid smartphone or tablet use 2 hours before bedtime. These emit blue light which interferes with the production of the hormone melatonin giving our body the signal to be awake, not asleep. If this is unavoidable use amber lens glasses which filter the blue light from your screen.
Make your bedroom a place of complete darkness. Consider using a red light if a night light is needed for children.
If you wake regularly in the night and find it hard to get back to sleep try these ideas to retrain your brain:
- Breathe deeply and focus on breathing to avoid busy brain syndrome. Try repeating ‘breathe in, breathe out’ in your head as you breathe to push out unwanted thoughts.
- Avoid turning on the light.
- Avoid getting out of bed. If you need to use the bathroom then cut your evening consumption of fluids.
- Avoid looking at a clock. Knowing the time will invite panic thoughts about how long you have been awake, how little sleep you have had and how few hours there are left until you must wake up.
- Avoid looking at any electrical device.
Try listening to this podcast by Dr Rangan Chatterjee with Russell Foster, Professor of Circadian Neuroscience at Oxford University, for comprehensive information on sleep.
References
- Nature communications. May 2021 How people wake up is associated with previous night’s sleep together with physical activity and food intake. https://www.nature.com/articles/s41467-022-34503-2 accessed 22/3/2023
- https://www.sleepfoundation.org/how-sleep-works/how-much-sleep-do-we-really-need
- https://my.clevelandclinic.org/health/articles/22572-serotonin#:~:text=What%20is%20serotonin%3F,(your%20peripheral%20nervous%20system).
