Does meal selection matter in treating insomnia?

Sleeplessness can be defined as difficulties in falling asleep and/or maintaining a continuous sleep, waking up too early, or experiencing subjective poor sleep quality that negatively affects daytime functioning. In order to classify the data as sleeplessness, it must occur at least three nights a week and cause fatigue, irritability, drowsiness the next day, impairments in concentration, attention, and memory, or a marked deterioration in mental and social functioning. Sleep problems should not be due to insufficient sleep duration or unsuitable sleep conditions such as noise, light, or inadequate room temperature. The frequency of sleeplessness increases with age but also occurs in children and adolescents. Estimates suggest that nearly 20% of adult Poles suffer from sleeplessness, and the proportion may be higher in older people and exceed 50% (A. Kańtoch 2016). Epidemiological data for children are less precise and indicate the occurrence of sleeplessness in a few to several percent (M. Kaczor, M. Skalski 2016). Sleeplessness is more common in women, particularly single women, than in men, and in the latter group, the high-risk group is the unemployed (I. Grabska-Kobyłecka, D. Nowak 2014). Poland, where the frequency of sleeplessness is 17.6% in a population-representative sample over 15 years of age, is within the range of the European average (A. Ostrowska 2018). However, there are significant differences between the general population and older people, partly due to the previous socio-economic situation of the country. In European countries, there is also a correlation between the occurrence of sleep disorders and the wealth of society. The higher the GDP (gross domestic product) per capita, the lower the frequency of sleeplessness. Unfortunately, Poland ranks the worst in this comparison and lags far behind countries such as Norway, Sweden, Denmark, Germany, or the Netherlands (A. Ostrowska 2018).

The main causes of sleep disturbances include: significant or chronic stress, emotional tension, mental illnesses such as depression or anxiety, various medical conditions (pain, fever, shortness of breath, restless legs), excessive consumption of alcohol or coffee, especially in the evening, the use of certain medications, particularly overdosage, and potential adverse effects disrupting sleep, age-related psychosocial changes: reduced mobility, limited social contact, retirement, and lifestyle changes, – disregarding sleep hygiene rules: excessive time spent in bed before sleeping and engaging in other activities (working, watching TV, eating in bed), unnecessary daytime naps, using the phone before falling asleep, light or noise exposure, inadequate room temperature, uncomfortable bed, – shift work, time zone changes (jet lag), – sedentary lifestyle, lack of physical activity, – improper diet, overeating before bedtime.

Sleep constitutes an extremely important component of life, enabling the rehabilitation of the body, the proper progression of life processes, and the regulation of circadian rhythm. Insufficient sleep may result in a multitude of detrimental health consequences. It is not only associated with impaired daytime functioning but also with an increased risk of future metabolic disorders: obesity and type 2 diabetes, hypertension, or metabolic syndrome. Low sleep quality is linked with amplified sensations of hunger, uncontrolled and emotional eating, as well as the development of eating disorders, such as night eating syndrome. In young individuals, a lack of sufficient sleep and sleep quality may lead to decreased mood, difficulties in concentration and memory, loss of motivation, and deterioration in work performance. In older individuals, the absence of sleep may be one of the causes of falls. Daytime fatigue, concentration, and attention issues lead to a decrease in physical performance, including motor coordination. Prolonged application of benzodiazepines during the treatment of insomnia or their overdose may result in diminished physical activity and correlate positively with the frequency of hip fractures in individuals over 65 years of age. Sleep deprivation is also associated with cognitive impairments, dementia, anxiety disorders, and depression. Individuals suffering from insomnia engage in physical activity less frequently and have poorer nutrition. Chronic sleep disorders also lead to a decrease in immunity and an increase in susceptibility to infections.

Ensuring appropriate sleep hygiene is the initial and fundamental step of therapy. In case of sleep issues, it is advisable to get out of bed, inhale deeply, and perform something soothing (e.g., a break from noise and lighting). It is recommended that rest and excitement periods be relatively constant throughout the week, and the bed is used solely for sleeping. Prior to sleep, it is optimal to pacify emotions and evade emotional triggers.

A balanced diet can also aid in the treatment of insomnia. Many components can promote sleep quality and development. These include minerals such as magnesium, zinc, calcium, and potassium, which regulate nerve movements and reduce stress and nervous tension. Supplementation with magnesium (500 mg for 8 weeks) has been shown to improve sleep quality and effectiveness (I. G. Grabsk-Kanker, D. Nowaker 2014). Tryptophan is an exogenous amino acid necessary for the biosynthesis of melatonin and serotonin, which facilitate sleep. Sources of tryptophan in the diet can include dairy products, lean meats, fish, eggs, nuts, or legumes. Vitamins B6, B12, and D are important for good sleep quality. In the event of a deficiency, they should be supplemented (I. G. Grabsk-Kanker, D. Nowaker 2014; M. Zhao et al., 2020). Omega-3 fatty acids are found in large amounts in fatty sea fish (e.g., salmon, tuna, mackerel, herring, sardines, or halibut). They have anti-inflammatory effects and are precursors of substances (e.g., prostaglandins) that facilitate sleep and alleviate anxiety or other depression symptoms, thereby indirectly affecting sleep quality. In the treatment of insomnia, the use of herbs such as St. John's wort, chamomile, hops, or lemon balm can be helpful. They are available in the form of teas or dietary supplements that contain extracts or mixtures of the above herbs. In recent years, the positive effect of cherry juice on sleep quality has been discovered (M. -P. St-Onge, A. Mikic, C. E. Pietrolungo, 2016). This may be due to the high content of polyphenols and melatonin in this fruit. Diet based on unprocessed products, with a low glycemic index, and adequate protein intake can also positively affect sleep.