Can tryptophan supplement intake at breakfast enhance melatonin secretion at night?
Can tryptophan supplement intake at breakfast enhance melatonin secretion at night?
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DOI：
10.1186/s40101-017-0135-9
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发表时间：
2017-02-28
影响因子：
3.1
通讯作者：
Wakamura T
中科院分区：
文献类型：
--
作者：
Nagashima S;Yamashita M;Tojo C;Kondo M;Morita T;Wakamura T
色氨酸（Tryptophan，TRP）是一种必需氨基酸，有研究表明，早餐摄入TRP结合白天明亮的光线照射可以增加夜间褪黑激素的分泌。然而，所涉及的机制尚不清楚。本研究的目的是研究在不同的白天光照强度下，在早餐时摄入TRP补充剂对人类夜间褪黑激素分泌的影响。12名受试者（年龄21.3 ± 3.0岁，平均值±标准差）在实验室环境中在4种条件下随机参加了持续3天的实验。四种条件为TRP*Bright、安慰剂 *Bright、TRP*Dim和安慰剂 * Dim。早餐时服用TRP胶囊（1000 mg）或安慰剂淀粉胶囊（1000 mg）。此外，在白天（07：00-18：00），受试者被要求保持在不同的光照强度下：>5000 lx（明亮）或<50 lx（昏暗）。收集唾液样品用于测量褪黑激素的浓度。采用重复测量方差分析（ANOVA）比较四种条件下褪黑素浓度和暗光褪黑素起效时间（DLMO）的时间过程。夜间褪黑激素浓度在明亮的光条件下往往高于在昏暗的光条件下（光的主要影响：p = 0.099）。此外，在明亮的光线条件下，基线和干预后DLMO的变化显著高于昏暗光线条件下的变化（光线的主要影响：p <0.001）。然而，方差分析结果表明，TRP摄入量对褪黑激素分泌没有显着影响。我们的研究结果表明，尽管TRP是褪黑激素的前体，但1天早餐摄入1000 mg TRP并没有改变夜间褪黑激素的分泌。相比之下，白天明亮的光线照射增加了夜间褪黑激素的分泌，提前了褪黑激素的发病阶段。因此，与暴露于白天明亮的光线不同，TRP补充剂不会严重影响人类的生物节律和睡眠。UMIN临床试验登记研究：UMIN 000024121本文的在线版本（doi：10.1186/s40101-017-0135-9）包含补充材料，授权用户可以使用。
Tryptophan (TRP) is an essential amino acid, and it has been suggested that TRP intake at breakfast combined with daytime bright light exposure can increase nocturnal melatonin secretion. However, the mechanisms involved are not yet clear. The aim of this study was to examine the effect of TRP supplement intake at breakfast on nocturnal melatonin secretion under different daytime light intensities in humans. Twelve subjects (aged 21.3 ± 3.0 years, mean ± standard deviation) participated in a random order in experimental sessions lasting 3 days under four conditions in a laboratory setting. The four conditions were TRP*Bright, Placebo*Bright, TRP*Dim, and Placebo*Dim. A TRP capsule (1000 mg) or a placebo starch capsule (1000 mg) were taken at breakfast. In addition, during the daytime (07:00–18:00), the subjects were asked to stay under different light intensities: >5000 lx (bright) or <50 lx (dim). Saliva samples were collected for measuring the concentration of melatonin. The time courses of melatonin concentration and dim light melatonin onset (DLMO) were compared among the four conditions using repeated measurements analysis of variance (ANOVA). Nocturnal melatonin concentrations in the bright light condition tended to be higher than in the dim light condition (main effect of light: p = .099). Moreover, in the bright light condition, the change in DLMO between baseline and after the intervention was significantly higher than that in the dim light condition (main effect of light: p <.001). However, the ANOVA results indicated no significant effect of TRP intake on melatonin secretion. Our findings indicated that intake of 1000 mg of TRP at breakfast on 1 day did not change nocturnal melatonin secretion, even though TRP is the precursor of melatonin. In contrast, daytime bright light exposure increased nocturnal melatonin secretion and advanced the phase of melatonin onset. Therefore, TRP supplementation, unlike exposure to daytime bright light, does not acutely affect biological rhythm and sleep in humans. UMIN Clinical Trial Registry: UMIN000024121 The online version of this article (doi:10.1186/s40101-017-0135-9) contains supplementary material, which is available to authorized users.