Tryptophan-enriched cereal intake improves nocturnal sleep, melatonin, serotonin, and total antioxidant capacity levels and mood in elderly humans

Abstract

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. Data were collected for 3 weeks according to the following schedule: The control week participants consumed standard cereals (22.5 mg tryptophan in 30 g cereals per dose) at breakfast and dinner; for the treatment week, cereals enriched with a higher dose of tryptophan (60 mg tryptophan in 30 g cereals per dose) were eaten at both breakfast and dinner; the posttreatment week volunteers consumed their usual diet. Each participant wore a wrist actimeter that logged activity during the whole experiment. Urine was collected to analyze melatonin and serotonin urinary metabolites and to measure total antioxidant capacity. 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

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“…In addition, Bartol-Munier and colleagues (4) have reported that both locomotor activity and interdaily stability drop during wakefulness due to diet, when a high-fat diet is administered to get obese animals. Moreover, these changes were confirmed by our research group previously in a similar essay carried out in animals which were fed a high-fat diet (6).…”

Free-radical scavenging by tryptophan and its metabolites through electron transfer based processes

“…It has been found that consuming tryptophan-enriched cereal improves nocturnal sleep and mood in elderly humans; and also increases melatonin, serotonin, and total antioxidant capacity levels [23]. The antioxidant effects of edible lotus rhizomes have been attributed to tryptophan [24].…”

The role of imbalance between urinary hexanoyl-lysine and total antioxidant capacity levels and its relation to plasma superoxide dismutase levels in autism spectrum disorder

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