Nutritional Modulators of Sleep Disorders

Background: Clinical evidence indicates that insufficient sleep and poor sleep quality appear to be common consequences of shift work. These rhythms appear to have independent influence on the function of the endocrine system, circadian brain function and gastrointestinal tract. Insufficient sleep and its poor quality due to shift work interfere with beta cells, leptin and ghrelin functioning, resulting in factors for the development and exacerbation of insulin resistance. Human studies found that insufficient sleep alters the levels of leptin and ghrelin, two hormones involved in the regulation of appetite and body fat. Leptin, released by fat cells, signals the brain to feel satiety. Ghrelin, produced in the stomach, signals hunger. Investigations reported that temporarily sleep-deprived individuals experienced hormonal changes along with greater cravings for sweet and fatty foods. A further reason for their cravings is related to the stress hormone cortisol, which can rise with sleep deprivation and contribute to hunger. In addition to altered hormone levels, people who stay awake longer have more opportunity to eat, and late-night eating often includes high-caloric foods. Weight gain is only one of the many side effects of insufficient sleep, but it can lead to long-term health problems, including diabetes. Although more sleep will not automatically result in weight loss, sufficient sleep and a regular sleep schedule are critical in controlling appetite and promoting a healthy eating pattern. Research on sleep and appetite reveals a consistent link between a lower amount of sleep and a higher body mass index (BMI), a ratio of weight-to-height that indicates overweight. Studies showed those who slept less than eight hours a night were more likely to be overweight. Methods: Internet search and discussion with colleagues. Results: Recent research indicates that disruption of sleep can influence food intake and food and nutrients can influence sleep. There is evidence that high protein and carbohydrates meals can influence moods, attention and concentration among normal adult subjects with respect to age, gender and meal time. Women reported greater sleepiness after two hours of carbohydrate meal as opposed to a protein meal. On the other hand men reported greater calmness after a carbohydrate as opposed to a protein meal. Age of subjects may also influence the response to meals. After a carbohydrate or protein rich breakfast, persons older than 40 years felt more tense and less calm with a protein-rich than carbohydrate- rich meal. In general older subjects preferred carbohydrate than protein meals. Carbohydrate meals are also reported to impair objective performance; carbohydrate rich foods either in breakfast or lunch have exhibited negative influence on neural response such as impaired objective performance and poor sustained attention. A meal consumed close to bedtime is associated with sleep disturbances. Further, solid foods as well as large meals may cause more sleepiness than liquid foods. Studies have also shown that the larger the meal, the sleepier the person thereafter. In the evening the sleep- facilitating effects of carbohydrates may be beneficial. However, manipulation in the energy content of meals for a single day may cause increase in markedly different levels of insulin without changes in plasma glucose. Conclusions: The findings indicate that food intake can influence sleep and disruption of sleep can cause increased consumption of fast ready-prepared foods which have adverse effects resulting in obesity, diabetes and CVDs.