My sleep research has uncovered some interesting facts. The neurotransmitter balance, the relative presence of different neurotransmitters, appears to play a significant role in fatigue. These neurotransmitters all have dietary precursors. Sleep and diet is therefore closely linked. If the diet is insufficient in a certain nutrient this will result in a decline in the availability of a required precursor and one outcome will be altered mood, or a possible cognitive impairment.
One key “sleep chemical” is the protein Tryptophan. See below for a link which leads to a table showing foods containing high levels of Tryptophan. One word of caution is apparent from these studies. The “chemical engine” that drives the mind is not fully understood by science. A reductionist focus on a single nutrient is likely to be incorrect and may possibly be harmful. There is considerable evidence the human body best utilizes micro-nutrients when these are made available in a diet that includes other associated micro-nutrients. The most efficacious combination of dietary inputs is not fully known. The interactions between dietary inputs is not understood. What does seem to be clear is that a holistic approach to ensuring a complete diet containing the full range of necessary nutrients is of greater importance than a focus on any single nutrient in isolation.
I have included the abstract of one article as the full text is not available to me. this is followed by a number of useful links in the sleep and diet topic area.
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Sleep in Elite Athletes and Nutritional Interventions to Enhance Sleep
Abstract
Sleep has numerous important physiological and cognitive functions that may be particularly important to elite athletes. Recent evidence, as well as anecdotal information, suggests that athletes may experience a reduced quality and/or quantity of sleep.
Sleep deprivation can have significant effects on athletic performance, especially submaximal, prolonged exercise. Compromised sleep may also influence learning, memory, cognition, pain perception, immunity and inflammation. Furthermore, changes in glucose metabolism and neuroendocrine function as a result of chronic, partial sleep deprivation may result in alterations in carbohydrate metabolism, appetite, food intake and protein synthesis. These factors can ultimately have a negative influence on an athlete’s nutritional, metabolic and endocrine status and hence potentially reduce athletic performance.
Research has identified a number of neurotransmitters associated with the sleep–wake cycle. These include serotonin, gamma-aminobutyric acid, orexin, melanin-concentrating hormone, cholinergic, galanin, noradrenaline, and histamine. Therefore, nutritional interventions that may act on these neurotransmitters in the brain may also influence sleep. Carbohydrate, tryptophan, valerian, melatonin and other nutritional interventions have been investigated as possible sleep inducers and represent promising potential interventions.
In this review, the factors influencing sleep quality and quantity in athletic populations are examined and the potential impact of nutritional interventions is considered. While there is some research investigating the effects of nutritional interventions on sleep, future research may highlight the importance of nutritional and dietary interventions to enhance sleep.
Sleep in Elite Athletes and Nutritional Interventions to Enhance Sleep
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Tryptophan-enriched cereal intake improves nocturnal sleep, melatonin, serotonin, and total antioxidant capacity levels and mood in elderly humans
Abstract (Partial)
Melatonin and serotonin rhythms, which exhibit a close association with the endogenous circadian component of sleep, are attenuated with increasing age. This decrease seems to be linked to sleep alterations in the elderly. Chrononutrition is a field of chronobiology that establishes the principle of consuming foodstuffs at times of the day when they are more useful for health, improving, therefore, biorhythms and physical performance. Our aim was to analyze whether the consumption of cereals enriched with tryptophan, the precursor of both serotonin and melatonin, may help in the reconsolidation of the sleep/wake cycle and counteract depression and anxiety in 35 middle-aged/elderly (aged 55–75 year) volunteers in a simple blind assay.
The consumption of cereals containing the higher dose in tryptophan increased sleep efficiency, actual sleep time, immobile time, and decreased total nocturnal activity, sleep fragmentation index, and sleep latency. Urinary 6-sulfatoxymelatonin, 5-hydroxyindoleacetic acid levels, and urinary total antioxidant capacity also increased respectively after tryptophan-enriched cereal ingestion as well as improving anxiety and depression symptoms. Cereals enriched with tryptophan may be useful as a chrononutrition tool for alterations in the sleep/wake cycle due to age.
Tryptophan-enriched cereal intake improves nocturnal sleep
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Dietary sources of Tryptophan
(Includes a table listing sources)
Tryptophan is a routine constituent of most protein-based foods or dietary proteins. It is particularly plentiful in chocolate, oats, dried dates, milk, yogurt, cottage cheese, red meat, eggs, fish, poultry, sesame, chickpeas, almonds, sunflower seeds, pumpkin seeds, spirulina, bananas, and peanuts. Contrary to the popular belief that turkey has a particularly high amount of tryptophan, the amount of tryptophan in turkey is typical of most poultry.