Insomnia is a sleep disorder frequently characterized by having difficulty in initiating and maintaining sleep, having trouble returning to sleep after multiple awakenings during the night, and failing to sleep again after early morning awakenings (1) (2). This insufficient sleep duration can be a huge burden on people’s life.
Insomnia can cause psychological distress to individuals affected by it and have adverse effects on their quality of life (3). Increased risk of depression and anxiety were also associated with insomnia (4).
There is an increasing amount of evidence suggesting a link between diet and sleep quality (5) . Given the associated risks with insomnia, it’s essential to look into how nutrition can have a negative or a positive impact on insomnia.
High Glycaemic Index (GI) foods were associated with an increased risk of insomnia. High GI foods are carbohydrates that break down quickly during digestion causing a rapid rise in blood sugar followed by increased insulin secretion (6). Some examples of High GI foods are white bread, rice, biscuits, and breakfast cereals (7)
The mechanism in which high GI foods can increase insomnia risk is that after consuming high GI foods, the blood sugar levels increase rapidly, causing a compensatory rise in insulin which will result in lowering blood glucose levels. These low blood sugar levels will trigger the release of counter-regulatory hormones such as adrenaline, cortisol, glucagon, and growth hormone, these hormones can contribute to insomnia by causing an increase in heart rate, tremors, hunger, irritability, and anxiety (8). Another mechanism in which high GI foods can cause insomnia is that they stimulate the release of inflammatory immune responses, and they can alter the intestinal microbiome, both can hinder sleep and lower sleep quality (9).
Key Actions for Balancing Blood Sugar
Focus on eating unrefined carbohydrate sources and avoid intake of high GI foods at night. When consuming high GI food try to combine them with protein and fibre sources to help lower sugar release.
Side effects: None
Contraindications with medication: Diabetes medication should be closely monitored by a doctor since dosages may need to be lowered if sugar intake is reduced significantly.
Saturated fatty acids (SFAs) are fatty acids that are mainly present in animal fat and processed deep-fried foods (9) (Zhao et al 2020). SFAs were negatively associated with insomnia as it was established that higher consumption of SFAs during the day was linked to a shorter period of slow sleep wave, which is the deepest sleep stage (10) (11).
Omega- 3 Polyunsaturated Fatty Acids are types of polyunsaturated fatty acids (PUFA) that can be found in oily fish such as salmon and tuna (12). There is evidence that a diet deficient in Omega-3 disturbed nocturnal sleep though affecting the melatonin rhythm and circadian clock functions (9). Interestingly, high-EPA fish oil supplements were associated with a disturbance in sleeping (9).
Key Actions for Increasing Omega 3
Limit your saturated fat intake to less than 5% a day. Aim to increase your intake of seafood containing omega-3 such as seabass, oysters, salmon at least twice a week. If you’re taking omega-3 supplements consume the in the morning with breakfast or lunch whichever has the higher fat content.
Side effects: omega 3 supplements can leave a fishy after taste and may cause loose stools in some individuals.
Contraindications with medication: always consult a doctor and qualified dietitian of nutrition practitioner before commencing any supplement recommendation. Omega 3 supplements contraindicate with blood thinners, such as warfarin and heparin.
Alcohol consumption can contribute to or further worsen insomnia as it was linked to poor sleep quality and a higher rate of waking up in the middle of the night (13). Caffeine is one of the most frequently used psychoactive stimulant drugs and can be found in beverages such as coffee, tea, and energy drinks (14) . Increased caffeine consumption can lower sleep quality and increase insomnia symptoms by causing impairments in night-time sleep by blocking the adenosine neuromodulator and receptor system that play a vital role in sleep-wake regulation (14) (15).
Keys Actions for Managing Alcohol and Caffeine
Limit your alcohol intake equal to or less than 14 units of alcohol per week, if you often drink 14 units of alcohol per week spread your drinking over 3 or more days (16). Avoid drinking beverages containing caffeine during the night and limit your caffeine intake to less than 400 mg a day which is equivalent to approximately 4 cups of coffee (17).
Side effects: Alcohol and caffeine can be coping mechanisms for some individuals, which can be a barrier to individuals for addressing intake. Reducing slowly, and swapping for alcohol and caffeine free alternatives can be a really positive way of supporting the transition. y companies now offer alcohol free alternatives to classic favourites such as beer and cider, with many low and no added sugar versions available. Moreover, kombucha, a probiotic fermented green tea drink is also a great alternative, having a cider-like taste but supporting gut health. In terms of caffeine free alternatives, herbal teas such as peppermint, chamomile and rooibos (redbush) can be enjoyed.
Contraindications with medication: Caffeine and alcohol can impact on blood sugar stability. Diabetes medication should be closely monitored by a doctor since dosages may need to be lowered if alcohol and caffeine are reduced significantly.
Vitamin D is a fat-soluble vitamin and can be either obtained through sunlight exposure or from dietary sources such as oily fish (sardines and salmon),liver, egg yolk and mushrooms (18).
There is evidence that suggests that vitamin D deficiency is associated with a higher risk of sleep disorders including poor sleep quality, short sleep duration, and sleepiness, however, the mechanism by which Vitamin D affects sleep quality is still not clear (9). Vitamin D deficiency is widely common as more than 50% of the population is at risk of being Vitamin D deficient (20). Vitamin D deficiency can be due to inadequate sun exposure, low consumption of food containing vitamin D, and high adiposity (21).
Key Actions for Increasing Vitamin D
Try to get 20-30 minutes of sunlight exposure every day as well as focus on consuming foods containing vitamin D. Regularly check your serum vitamin D levels (preferably every 3 months) to see if you’re deficient since vitamin D deficiency is quite common and you might need to take Vitamin D supplements to raise your vitamin D serum levels.
Vitamin D is present in some foods, such as milk and mushrooms. However, the main way in which the body obtains Vitamin D is via sunlight exposure, and this can be impacted on the time of year. For this reason, the UK government currently recommends that many populations supplement 10mcg (400IU) of Vitamin D daily. Individuals who have a darker skin tone, have a higher BMI, and are from particular religious groups which encourage skin to be largely covered up are at a higher risk of Vitamin D deficiency.
Side Effects:
Contraindications: Vitamin D medications can contraindicate with anti-epilieptic medications, Orlistat (weight loss medication), heart medications, steroids and diuretics, so always consult a doctor before consuming Vitamin D supplements. Pregnant and breastfeeding individuals should also seek advice from their midwife and doctor before supplementation.
Vitamin B12 is an essential vitamin that the body is not able to synthesize, and it must be obtained from dietary sources such as meat, eggs, cheese, and fortified cereals (22) . Vitamin B-12 was shown to improve sleep quality which might be due to the influence it has on plasma melatonin levels (23). Melatonin is a hormone that is secreted from the brain in response to darkness and it helps with sleep and regulates sleep-wake cycles (24). Moreover, lower serum vitamin B-12 levels were associated with shorter sleep duration (25).
Key Actions for Increasing Vitamin B12
If you’re experiencing short sleep duration it might be helpful to be mindful of eating food sources rich in Vitamin B12 such as meat, eggs, cheese, and fortified cereals.
Side effects: High dosages of B12 can cause:
Contraindications with medication: Vitamin B12 supplementation should be avoided in situations of sensitivity to cobalt and/or vitamin B12 due to the risk of anaphylaxis. Patients with early Leber disease and kidney disease should seek advice from a doctor to discuss options regarding supplementation.
Researcher: Aseel Sharkas BSc Human Nutrition & Dietetics, MSc Nutrition and Behaviour
