Summary:
In today’s fast-paced world, dealing with stressors and consequent sleep disturbances is becoming increasingly common. While melatonin is widely recognized for its role in regulating sleep, three amino acids that are emerging as effective supplements for promoting relaxation and improving sleep quality are gamma-aminobutyric acid (GABA), L-theanine, and 5-hydroxytryptophan (5-HTP).* The following explores the benefits of these amino acid supplements, providing an understanding of how they can support stress management and enhance sleep to ultimately contribute to overall well-being.*
Gamma-Aminobutyric Acid (GABA)
Gamma-aminobutyric acid, known as GABA, is the primary inhibitory neurotransmitter in the central nervous system that plays an important role in reducing neuronal excitability. By binding to GABA receptors, it functions in the body to help calm the nervous system and GABA supplementation has been investigated for its potential benefits in stress management and sleep quality.*
In an animal study, oral administration of GABA significantly lowered stress-induced negative responses based on behavioral and biochemical assessments.*[1] Another study conducted on 63 healthy adults (28 males, 35 females) found that a singular 100 mg oral dose of GABA significantly decreased alpha and beta waves after completing a stress-inducing mental task as compared to placebo.*[2] Additionally, the alpha and beta wave decrease diminished 30 minutes after GABA intake, indicating a stress-protective effect of GABA and suggesting that GABA may be able to pass the blood brain barrier in small or full amounts to exert effects on the central nervous system.*[3]
The evidence for GABA’s role in improving sleep quality is limited but may possibly be advantageous.* Twenty (20) postmenopausal female participants were given GABA-enriched rice, three times a day, totaling a dose of 26.4 mg per day for 4 weeks. In the experimental group, significant improvements were noted of sleep quality based on the Kupperman Menopause Index after the 4th week of the treatment as compared to the control group.*[4]
Additionally, the intake of 100 mg GABA capsule (versus control) found subjective improvement upon awakening, and objective results of reduced sleep latency and increased total non-REM sleep time after 1 week of intervention on middle aged individuals who reported having occasional poor sleep.*[5]
Although the ability of supplemental GABA to cross the blood-brain barrier (BBB) under normal conditions is complex and not fully understood, there is some evidence of a specialized GABA transporter in the BBB.[6] It has been proposed that the effects seen clinically with GABA supplementation are due to the binding of receptors in the nervous system within the digestive tract and are modulated by the vagus nerve.*[7]Additionally, liposomal delivery systems may facilitate transport across the BBB and increase availability of therapeutic agents in the central nervous system.*[8]
L-Theanine
L-theanine is naturally found in tea leaves, particularly green tea, and has been gaining increasing popularity for its potential benefits in stress management and sleep quality.*
A daily dose of 200 mg of L-theanine administration for 4 weeks on 30 healthy individuals (9 men and 21 women) with an average of 48 years of age found promising results compared to the placebo group. There was a decrease in subjective stress-related symptoms based on a validated questionnaire. The Pittsburgh Sleep Quality Index (PSQI) subscale score for sleep latency, sleep disturbance, and use of other sleep medication was reduced in the L-theanine group. Lastly, self-reported verbal fluency and executive function scores improved after L-theanine administration.*[9]
An additional point of interest is that L-theanine has been shown to reduce subjective experiences of stress and salivary α-amylase activity, a marker of sympathetic nervous system activity and the “fight or flight” response, during academic challenges.* This study was completed on 20 5th-year university students and were provided 200 mg L-theanine capsules twice a day (after breakfast and lunch) for about 2.5 weeks.[10]
L-theanine continues to be studied for the impacts it may have on learning and memory, attention, mood, and other mental health benefits and has been shown to be well tolerated.*
5-Hydroxytryptophan
5-hydroxytryptophan (5-HTP) is an amino acid produced in the body from the essential amino acid tryptophan. 5-HTP is the immediate precursor to serotonin, which later converts to melatonin. The enzyme 5-hydroxytryptophan decarboxylase converts 5-HTP to serotonin and requires vitamin B6 (pyridoxine).[11],[12] Evidence suggests that supplemental 5-HTP is well absorbed orally, and easily crosses the blood brain barrier.[13],[14]
In 30 older adults (average age of 66 years) that were administered 100 mg of 5-HTP daily for 12 weeks, global sleep scores (GSS) significantly improved and an increase in serum serotonin concentration was observed.*[15]
In 45 children (34 males and 11 females) ages 3-10 years, a dosage of 2 mg/kg of 5-HTP at bedtime for 21 consecutive days, showed 5-HTP to significantly reduce the occurrence of night terrors, with no negative side effects.[16]
In today's fast-paced world, stress and sleep disturbances are common, and three amino acids including GABA, L-theanine, and 5-hydroxytryptophan (5-HTP) are emerging as effective supplements for promoting relaxation and improving sleep quality.* GABA helps calm the nervous system, L-theanine supports stress management and enhances sleep, and 5-HTP boosts serotonin levels, which can improve sleep and reduce stress.* These amino acids are additional tools for better sleep and relaxation, contributing to overall well-being.*
The information provided is for educational purposes only. Consult your physician or healthcare practitioner if you have specific questions before instituting any changes in your daily lifestyle including changes in diet, exercise, and supplement use.