Nutritional Interventions for Enhancing Sleep Quality: The Role of Diet and Key Nutrients in Regulating Sleep Patterns and Disorders

A comprehensive review of the literature was conducted to explore the role of dietary interventions and specific nutrients in regulating sleep patterns and addressing sleep disorders. We systematically searched peer‐reviewed clinical trials, observational studies, and mechanistic research published over the past two decades. The search was performed using three major scientific databases: PubMed, ScienceDirect, and Google Scholar. Search terms included combinations of the following keywords: "sleep quality," "sleep disorders," "dietary patterns," "nutritional interventions," "functional foods," "probiotics and sleep," "tryptophan and melatonin," "circadian rhythms and diet," and "gut microbiome and sleep."

From an initial pool of 1327 articles retrieved, studies were screened based on titles and abstracts. After removing duplicates and applying inclusion and exclusion criteria, a total of 161 key studies were selected for full analysis in this review.

Studies were included if they met the following criteria: Human or animal studies examining the relationship between diet, specific nutrients, dietary patterns, or gut microbiota and sleep parameters. Clinical trials (randomized controlled trials [RCTs] or open‐label trials), cohort studies, cross‐sectional studies, case–control studies, or mechanistic experimental studies. Reported specific outcomes related to sleep quality, sleep latency, sleep duration, circadian rhythm alignment, or sleep disorders such as insomnia, obstructive sleep apnea, or restless leg syndrome. Provided clear methodological descriptions and statistically relevant findings.

The selection process involved two independent reviewers who first screened the titles and abstracts for relevance. Studies not focused on diet‐sleep interactions or those lacking primary data (e.g., editorials, narrative reviews without new analysis) were excluded. Full‐text review was performed for articles meeting initial criteria, with discrepancies resolved through discussion or consultation with a third reviewer. The final set of studies was categorized into five main thematic areas corresponding to the review's structure: key nutrients, dietary patterns, gut microbiota interactions, functional foods, and personalized nutrition.

Included studies spanned a range of designs: Randomized Controlled Trials (RCTs) evaluating specific food interventions (e.g., tart cherry juice, kiwifruit, omega‐3 supplementation) on sleep outcomes.Observational Cohort Studies analyzing associations between dietary patterns (e.g., Mediterranean, ketogenic, plant‐based diets) and sleep quality.Cross‐Sectional Analyses linking nutrient intake (e.g., tryptophan, magnesium) with sleep parameters.Mechanistic Studies investigating how specific nutrients or gut microbiota influence neurotransmitter production, melatonin synthesis, inflammation, and circadian regulation.

Special focus was given to interventions or exposures involving amino acids, minerals, polyphenols, probiotics, prebiotics, functional foods, and timing of food intake (chrononutrition).

Data were systematically extracted using a structured template capturing the following elements: Study design and sample size Population characteristics (e.g., healthy individuals, patients with insomnia, sleep apnea sufferers) Type and duration of dietary intervention or exposure Specific nutrients, foods, or dietary patterns examined Sleep‐related outcomes measured (e.g., sleep quality, latency, efficiency, REM/non‐REM distribution) Key findings, effect sizes, and statistical significance Proposed biological mechanisms (e.g., neurotransmitter modulation, circadian gene expression, gut‐brain axis communication)

The primary outcomes of interest were: Changes in sleep duration, latency, and efficiency Improvement or deterioration in subjective sleep quality Alterations in circadian rhythm parameters Mechanistic insights into diet‐related modulation of sleep architecture

Studies with robust designs (e.g., RCTs, large cohort studies) and strong methodological quality were weighed more heavily in the narrative synthesis, while mechanistic studies were used to support the biological plausibility of observed effects.

This review is a narrative synthesis and does not adhere to PRISMA guidelines. While extensive efforts were made to identify relevant studies, the potential for publication bias and selective inclusion remains. The findings should therefore be interpreted as an integrative overview rather than a systematic meta‐analysis.

While numerous studies indicate associations between specific nutrients and improved sleep outcomes, most evidence remains correlational. Except for well‐controlled randomized trials, causal relationships cannot be conclusively established. Therefore, the terms "is associated with," "may influence," or "has been linked to" are used throughout this review to reflect the current level of evidence.

Tryptophan is an essential amino acid that serves as a precursor for serotonin and subsequently melatonin—two neurotransmitters fundamental to sleep onset and maintenance (Richard et al. 2009). Dietary intake of tryptophan, whether through protein‐rich foods or supplementation, has been associated with shortened sleep latency and improved subjective sleep quality (Hudson et al. 2005). Tryptophan competes with other large neutral amino acids (LNAAs) for transport across the blood–brain barrier; thus, the carbohydrate‐to‐protein ratio in a meal can influence its availability to the brain (Silber and Schmitt 2010).

Glycine, another amino acid, exerts sleep‐promoting effects by acting as an inhibitory neurotransmitter in the central nervous system. Oral glycine supplementation has been shown to improve subjective sleep quality and reduce sleep onset latency, possibly by lowering core body temperature—a physiological signal of sleep initiation (Yamadera et al. 2007).

Magnesium plays a pivotal role in sleep regulation by modulating the activity of N‐methyl‐D‐aspartate (NMDA) receptors and GABAergic systems, both of which are crucial for sleep induction (Abbasi et al. 2012). Magnesium deficiency is linked to increased nocturnal awakenings and reduced slow‐wave sleep, emphasizing its importance for restorative sleep phases.

Zinc, a trace mineral with antioxidant and neuromodulatory properties, has been implicated in the regulation of sleep architecture. A study in infants and preschool‐aged children demonstrated a positive correlation between serum zinc levels and sleep duration (Liu et al. 2024; Giambersio et al. 2023; Sincana et al. 2022; Ji and Liu 2015; Cortese et al. 2009). Zinc may enhance sleep by influencing synaptic plasticity and the modulation of glutamatergic neurotransmission.

Iron is essential for the proper function of dopamine systems, which are critical in regulating sleep–wake cycles. Iron deficiency has been strongly associated with restless leg syndrome (RLS), a disorder characterized by unpleasant sensations and an uncontrollable urge to move the legs during rest (Hening et al. 2009; Allen et al. 2003). Iron supplementation has been shown to alleviate RLS symptoms and improve sleep quality.

Vitamin D receptors are expressed in several brain regions involved in sleep regulation, including the hypothalamus. Observational studies have linked low vitamin D status to an increased risk of sleep disorders, particularly short sleep duration and poor sleep efficiency (Faustine et al. 2024; Singh et al. 2024; Abboud 2022; Gao et al. 2018). The mechanistic pathways may involve modulation of inflammatory responses and melatonin synthesis.

The B‐vitamin group, particularly B6 (pyridoxine), B9 (folate), and B12 (cobalamin), plays roles in neurotransmitter metabolism. Vitamin B6 is required for the conversion of tryptophan to serotonin, while folate and B12 are involved in methylation processes that support melatonin synthesis (Li et al. 2023; Puga et al. 2021; Chen et al. 2021; Ma et al. 2019). Deficiencies in these vitamins have been linked to sleep disturbances such as insomnia and fragmented sleep patterns.

Polyphenols, particularly flavonoids found in fruits, vegetables, tea, and cocoa, have gained attention for their neuroprotective and sleep‐promoting properties. Flavonoids such as apigenin (found in chamomile) and kaempferol have anxiolytic and sedative effects through interactions with GABA_A receptors (Kramer and Johnson 2024; Salehi et al. 2019; Kim et al. 2012).

Other polyphenolic compounds like resveratrol (found in grapes and berries) and epigallocatechin gallate (EGCG) from green tea exhibit anti‐inflammatory and antioxidant effects that may indirectly benefit sleep by reducing systemic inflammation and oxidative stress (Zhang et al. 2024; Wei et al. 2024; Tseilikman et al. 2024). These actions are crucial, as chronic inflammation and elevated oxidative stress are implicated in insomnia and other sleep disturbances.

While endogenous melatonin secretion from the pineal gland is the primary driver of circadian sleep–wake rhythms, exogenous melatonin (from supplements or foods like tart cherries) has been increasingly utilized to support sleep, especially for individuals with circadian rhythm disorders (Pigeon et al. 2010). Melatonin supplementation has shown efficacy in reducing sleep onset latency, increasing total sleep time, and improving overall sleep quality.

L‐Theanine, an amino acid predominantly found in green tea, has shown promise in promoting relaxation without sedation. Clinical trials have reported that L‐theanine supplementation improves sleep quality, reduces sleep disturbances, and enhances the recovery phase of sleep through modulation of alpha brain wave activity and GABA levels (Lyon et al. 2011).

Nutritional modulation of sleep involves multiple biochemical and neurophysiological pathways that converge on circadian regulation, neurotransmitter balance, and hormone synthesis. Amino acids such as tryptophan act as precursors for serotonin and melatonin, both essential for sleep initiation and maintenance. The conversion of tryptophan to serotonin through tryptophan hydroxylase and subsequently to melatonin via arylalkylamine N‐acetyltransferase (AANAT) and hydroxyindole‐O‐methyltransferase (HIOMT) depends on cofactors such as vitamin B6 and magnesium, which facilitate enzymatic activation (Jenkins et al. 2016; Peuhkuri et al. 2012). Micronutrients including zinc and iron influence dopaminergic and GABAergic transmission, modulating sleep–wake transitions and cortical excitability (Cherasse and Urade 2017).

Dietary omega‐3 polyunsaturated fatty acids (PUFAs) alter neuronal membrane fluidity and enhance serotonin receptor signaling, indirectly improving sleep efficiency and mood regulation (Montgomery et al. 2014; Parletta et al. 2013). Magnesium and calcium further stabilize neuronal excitability through regulation of GABA_A receptor activity, promoting inhibitory neurotransmission and reducing nocturnal awakenings (Abbasi et al. 2012; Rondanelli et al. 2011). In parallel, polyphenols and flavonoids such as tart cherry, cocoa, and kiwifruit exert antioxidant and anti‐inflammatory effects that protect neuronal integrity and upregulate melatonin synthesis (Barforoush et al. 2025).

The gut–brain axis also constitutes a pivotal mechanistic interface whereby microbial metabolites—including short‐chain fatty acids, indole derivatives, and secondary bile acids—modulate serotonin production, vagal afferent signaling, and systemic inflammation, thereby influencing sleep architecture (Chen et al. 2025; Anderson et al. 2017). Diets rich in fermentable fibers, prebiotics, and probiotics such as Lactobacillus rhamnosus GG and Bifidobacterium longum have been shown to enhance GABA synthesis and melatonin secretion through this pathway (Kezer et al. 2025). Collectively, these mechanisms highlight the interdependence between nutrient availability, neurotransmitter synthesis, and circadian hormone regulation in sleep physiology.

Table 1 summarizes the key nutrients and bioactive compounds most frequently investigated in relation to sleep regulation, including their key outcomes, mechanisms, food sources, evidence type, and overall strength of support.

The biochemical interactions between dietary nutrients, neurotransmitter synthesis, and hormonal regulation are illustrated in Figure 1, highlighting the tryptophan–serotonin–melatonin pathway and the modulatory roles of cortisol and gut microbiota in sleep regulation.

The Mediterranean diet (MD), characterized by high consumption of fruits, vegetables, legumes, whole grains, nuts, olive oil, moderate fish and poultry intake, and limited red meat and sugar consumption, has been consistently associated with better sleep outcomes (St‐Onge et al. 2016). Studies suggest that adherence to the MD improves sleep duration, efficiency, and subjective sleep quality, possibly due to its anti‐inflammatory and antioxidative properties (Fallah et al. 2024; Godos et al. 2024; Godos et al. 2019).

Rich in polyphenols, omega‐3 fatty acids, and complex carbohydrates, the MD supports melatonin synthesis, reduces oxidative stress, and enhances serotoninergic neurotransmission—all critical pathways for sleep regulation (Pérez‐Jiménez et al. 2023; Wang et al. 2023; Williamson 2017). Moreover, magnesium‐rich foods, abundant in the MD, may contribute to sleep promotion through their role in NMDA and GABA receptor modulation.

A large cross‐sectional study by Li Rang et al. (2024) reported that higher adherence to the MD correlated with reduced risk of insomnia symptoms in older adults. The complex carbohydrates prevalent in the MD, by increasing the availability of tryptophan to the brain, may facilitate sleep onset and continuity (Afaghi et al. 2007).

The ketogenic diet (KD), a high‐fat, very low‐carbohydrate diet, has gained popularity for its therapeutic potential in epilepsy, obesity, and metabolic disorders. Recent findings suggest that the KD may also influence sleep architecture. Studies indicate that ketogenic states can increase the proportion of slow‐wave sleep (SWS) and decrease REM sleep, possibly due to alterations in adenosine signaling and energy metabolism (Oleszczuk et al. 2024; Borowicz‐Reutt et al. 2024; Ünalp et al. 2021).

A clinical trial by Hallböök et al. (2007) in children with epilepsy showed that KD improved sleep quality by reducing nocturnal awakenings and enhancing sleep efficiency. Furthermore, ketone bodies themselves may have neuroprotective and anti‐inflammatory effects that stabilize neuronal networks involved in sleep regulation.

However, the KD's impact on sleep can be complex. Initial phases of KD, often associated with keto‐adaptation symptoms ("keto flu"), may temporarily disrupt sleep, suggesting that the duration of adherence and individual metabolic responses are critical factors (Sanderlin et al. 2022; Gangitano et al. 2021; Barrea et al. 2021).

Plant‐based diets, including vegetarian and vegan diets, emphasize the consumption of plant‐derived foods such as fruits, vegetables, legumes, whole grains, nuts, and seeds, with minimal or no animal products. Epidemiological data suggest that plant‐based eaters often report better sleep quality compared to omnivores (Oussalah et al. 2020; Segovia‐Siapco and Sabaté 2019).

The high fiber content of plant‐based diets positively influences gut microbiota composition, enhancing gut‐brain axis signaling, which may contribute to improved sleep (Sejbuk et al. 2024; Lin et al. 2024). Additionally, the anti‐inflammatory profile of plant‐based diets, rich in phytonutrients and antioxidants, may reduce systemic inflammation—a factor linked to poor sleep outcomes (Dashti Hassan et al. 2015; Grandner et al. 2013).

However, careful dietary planning is necessary to prevent potential deficiencies in nutrients like vitamin B12, iron, and omega‐3 fatty acids, all of which are important for optimal sleep regulation. Studies have suggested that lower levels of these micronutrients may impair sleep quality (Gao et al. 2018; St‐Onge et al. 2016).

Emerging research in chrononutrition highlights that not only what we eat but also when we eat has significant effects on sleep health. Irregular meal timing, late‐night eating, and skipping breakfast have been associated with circadian misalignment, delayed sleep onset, and reduced sleep quality (Pot 2018).

Late‐night high‐fat or high‐energy meals can impair sleep initiation and depth by disrupting circadian hormonal rhythms, including melatonin secretion (Scoditti et al. 2022, Bakırhan et al. 2022). Conversely, consuming high‐glycemic index foods approximately 4 h before bedtime may reduce sleep onset latency, suggesting that strategic timing of meals can enhance sleep (Afaghi et al. 2007).

Time‐restricted eating (TRE), a form of intermittent fasting that aligns food intake within a restricted time window during the day, has shown promise in improving sleep efficiency and duration by strengthening circadian rhythms (Manoogian and Panda 2017).

Taken together, evidence supports that diet quality, meal composition, and timing synergistically influence sleep regulation. Diets emphasizing anti‐inflammatory, antioxidant‐rich foods—such as the Mediterranean and plant‐based diets—promote better sleep outcomes. Meanwhile, attention to meal timing and chrononutritional principles may further optimize sleep quality by reinforcing circadian homeostasis.

Figure 2 compares how major diets impact sleep parameters. Mediterranean and plant‐based diets are associated with improvements in sleep duration, efficiency, circadian stability, and melatonin production, along with reduced inflammation. The ketogenic diet shows mixed effects, with potential benefits for sleep efficiency but inconsistent outcomes on duration. Conversely, the Western diet is linked to deteriorated sleep quality and increased inflammation, highlighting the critical role of dietary quality in sleep health (Pasca et al. 2024; Fallah et al. 2024; Godos et al. 2024; Pattnaik et al. 2022; Zuraikat et al. 2020; St‐Onge et al. 2016; Grandner et al. 2013; Peuhkuri et al. 2012; Benedict et al. 2011; Huang et al. 2002).

Thus, dietary interventions aimed at improving sleep should not only focus on individual nutrients but also prioritize holistic dietary patterns and temporal eating behaviors, paving the way for more sustainable, lifestyle‐based strategies to manage sleep disorders.

Table 2 summarizes key dietary patterns and their documented effects on sleep quality, including key outcomes, underlying mechanisms, food sources, study types, and overall evidence strength.

Emerging research suggests that the gut microbiota can influence sleep through several mechanisms, including modulation of the immune system, regulation of metabolic pathways, production of neurotransmitters, and interaction with the circadian system (Lin et al. 2024; Wu et al. 2023; Zhe Wang et al. 2022; Thompson et al. 2017).

One key pathway involves microbial regulation of inflammatory cytokines, such as interleukin‐6 (IL‐6) and tumor necrosis factor‐alpha (TNF‐α), which are known to affect sleep architecture. Chronic low‐grade inflammation, often associated with gut dysbiosis (imbalanced gut microbiota), has been linked to insomnia and fragmented sleep (Irwin 2015). In contrast, a healthy gut microbiota promotes the production of anti‐inflammatory metabolites like short‐chain fatty acids (SCFAs), which have been associated with improved sleep continuity and quality (Anderson et al. 2017).

Additionally, certain gut bacteria synthesize key neurotransmitters, including gamma‐aminobutyric acid (GABA), serotonin, and dopamine, all of which are critical for sleep regulation (Clarke et al. 2013). Approximately 90% of the body's serotonin, a precursor to melatonin, is produced in the gut, emphasizing the microbiome's influence on circadian and sleep–wake cycles (Yano et al. 2015).

The gut microbiota itself exhibits circadian rhythmicity, with microbial composition and function fluctuating throughout the day in response to the host's feeding–fasting cycles and sleep patterns (Thaiss et al. 2014). Disruption of the host's circadian rhythm—such as through shift work, jet lag, or irregular eating patterns—can lead to microbial dysbiosis, which in turn exacerbates sleep disturbances (Zarrinpar et al. 2016).

Conversely, maintaining synchronized circadian rhythms through regular sleep schedules and meal timing can promote a healthy microbial community, thereby reinforcing sleep quality and metabolic health. This interplay suggests that interventions targeting the microbiome may be particularly effective in individuals suffering from circadian rhythm sleep disorders.

Probiotics—live microorganisms that confer health benefits to the host—have shown promise in improving sleep outcomes. Clinical trials indicate that probiotic supplementation with strains like Lactobacillus and Bifidobacterium species can reduce stress, improve mood, and enhance sleep quality (Huang and Liu 2024; Chu et al. 2023; Okubo et al. 2019; Daisuke et al. 2019; Mohammadi et al. 2016).

A randomized controlled trial by Nishida et al. (2019) demonstrated that a daily intake of Lactobacillus gasseri CP2305 significantly improved sleep efficiency and reduced sleep latency in adults with mild sleep disturbances. These effects were attributed to modulation of the hypothalamic–pituitary–adrenal (HPA) axis and reduction in salivary cortisol levels.

Prebiotics—nondigestible food components like inulin, fructooligosaccharides (FOS), and galactooligosaccharides (GOS)—also play a crucial role in shaping the gut microbiota and promoting the growth of beneficial bacteria. Animal studies have shown that prebiotic consumption can increase non‐REM sleep and improve resilience to stress‐induced sleep disruptions, possibly through enhanced SCFA production and altered gut‐brain signaling (Thompson et al. 2017).

Dietary fibers, found abundantly in fruits, vegetables, legumes, and whole grains, serve as substrates for microbial fermentation, leading to the production of SCFAs such as acetate, propionate, and butyrate. SCFAs have been shown to cross the blood–brain barrier and influence sleep regulation by modulating neuroinflammation and neuroplasticity (Dalile et al. 2019).

Moreover, higher fiber intake has been associated with deeper, more restorative sleep. In a controlled feeding study, St‐Onge et al. (2016) found that greater fiber consumption was linked to more time spent in slow‐wave sleep, whereas higher saturated fat intake was associated with lighter, less restorative sleep.

Thus, increasing dietary fiber intake represents a simple, non‐invasive strategy to modulate the gut microbiome and enhance sleep quality through the endogenous production of beneficial metabolites.

Dysbiosis has been implicated in the pathophysiology of various sleep disorders, including insomnia, obstructive sleep apnea (OSA), and restless leg syndrome (RLS). For example, individuals with OSA often exhibit altered gut microbiota composition characterized by reduced microbial diversity and increased abundance of pro‐inflammatory bacteria (Ko et al. 2019).

Figure 3 shows the emerging role of gut health in sleep regulation. Intake of probiotics, prebiotics, and polyphenol‐rich foods enhances gut microbiota diversity, leading to increased production of neuroactive metabolites such as short‐chain fatty acids and serotonin precursors. These metabolites influence brain function by modulating neurotransmitter levels (e.g., serotonin, GABA) and reducing cortisol and systemic inflammation, collectively contributing to improved sleep quality and duration. This figure highlights emerging pathways linking dietary modulation of the gut microbiome to sleep regulation (Bowers et al. 2022; Smith et al. 2019; Liang et al. 2018; Anderson et al. 2017; Thompson et al. 2017; Aarts et al. 2017; Benedict et al. 2016; Rea et al. 2016; Zheng et al. 2016; Barrett et al. 2012).

Restoring microbial balance through targeted dietary interventions, prebiotics, probiotics, and lifestyle modifications may offer adjunctive therapy for managing sleep disorders, although further clinical trials are needed to establish causality and therapeutic efficacy.

Recent studies have identified specific probiotic strains that exert measurable effects on sleep regulation through modulation of neurotransmitter pathways and stress hormones. Lactobacillus rhamnosus GG has been shown to enhance γ‐aminobutyric acid (GABA) receptor expression in the hippocampus and amygdala, promoting anxiolytic and sleep‐promoting effects via vagal signaling (Babaei et al. 2025; Magalhães et al. 2025). Similarly, Bifidobacterium longum 1714 and Lactiplantibacillus plantarum P8 have demonstrated reductions in cortisol levels and improvements in subjective sleep quality and sleep latency in both clinical and preclinical models (Nishida et al. 2019). These psychobiotic strains also influence serotonin metabolism by increasing tryptophan availability and modulating the kynurenine pathway, thereby enhancing central serotonin synthesis (Xia et al. 2025). Collectively, these findings highlight the potential of targeted probiotic interventions to regulate neurochemical pathways that underlie sleep architecture and circadian alignment.

Tart cherries (Prunus cerasus), particularly the Montmorency variety, are a natural source of melatonin, the hormone crucial for regulating the sleep–wake cycle. Tart cherry juice consumption has been linked to improvements in sleep duration and quality due to its melatonin content and antioxidant properties (Pigeon et al. 2010; Howatson et al. 2012).

A randomized, double‐blind, placebo‐controlled trial by Pigeon et al. (2010) found that adults with chronic insomnia who consumed tart cherry juice twice daily experienced modest improvements in sleep continuity. Similarly, Howatson et al. (2012) demonstrated that healthy individuals drinking Montmorency tart cherry concentrate increased sleep time by approximately 34 min and improved sleep efficiency, likely through enhanced endogenous melatonin availability.

Kiwifruit (Actinidia deliciosa) is rich in antioxidants, vitamins (particularly vitamin C and E), folate, and serotonin precursors, making it a promising food for sleep promotion. Clinical studies have shown that consuming two kiwifruits 1 h before bedtime significantly improves sleep onset, duration, and efficiency in individuals with sleep disturbances (Lin et al. 2011).

The beneficial effects are hypothesized to stem from kiwifruit's high serotonin content, which aids in regulating the sleep cycle by serving as a precursor to melatonin synthesis (Lin et al. 2011). Additionally, the antioxidative capacity of kiwifruit may reduce oxidative stress, which is implicated in the pathophysiology of sleep disorders.

Several herbal teas have been traditionally used for their sedative and anxiolytic effects, with chamomile (Matricaria chamomilla), valerian (Valeriana officinalis), lavender (Lavandula angustifolia), and passionflower (Passiflora incarnata) among the most studied.

Chamomile tea, rich in apigenin—a flavonoid that binds to benzodiazepine receptors in the brain—has been shown to promote sleepiness and reduce nighttime awakenings (Zick et al. 2011). Valerian root contains valerenic acid, which modulates GABAergic activity, thereby inducing sedative effects (Bent et al. 2006). A systematic review by Fernández‐San‐Martín et al. (2010) concluded that valerian preparations significantly improved sleep quality compared to placebo, although variability among studies exists.

Lavender and passionflower teas also demonstrate anxiolytic properties that may contribute to improved sleep through the modulation of central nervous system pathways involved in stress and arousal (Lillehei and Halcon 2014; Koulivand et al. 2013; Nogueira and Vassilieff 2000).

Omega‐3 polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are known for their anti‐inflammatory and neuroprotective properties. Recent evidence suggests that omega‐3 supplementation may also play a role in improving sleep patterns.

Montgomery et al. (2014) conducted a randomized controlled trial in children, showing that higher blood levels of DHA were associated with significantly fewer sleep disturbances. Additionally, supplementation with DHA‐rich fish oil led to longer sleep duration and fewer waking episodes.

The proposed mechanisms include modulation of melatonin secretion, reduction in pro‐inflammatory cytokines, and stabilization of neuronal membranes, all of which are critical for maintaining healthy sleep architecture (Grosso et al. 2014).

Emerging nutraceuticals are gaining popularity as adjunct therapies for sleep enhancement: Glycine, a non‐essential amino acid, has been shown to improve subjective sleep quality and reduce fatigue when taken before bedtime. Glycine likely exerts its effects by lowering core body temperature and enhancing vasodilation, key physiological changes for sleep initiation (Bannai et al. 2012).L‐theanine, a unique amino acid found in green tea (Camellia sinensis), promotes relaxation without sedation by increasing GABA, dopamine, and serotonin levels. Clinical studies report that L‐theanine supplementation improves sleep quality in individuals with generalized anxiety (Hidese et al. 2017, 2019).Cannabidiol (CBD), a non‐psychoactive compound derived from Cannabis sativa, has demonstrated potential for improving sleep through anxiolytic and analgesic effects. Although preliminary evidence supports CBD's role in reducing sleep disturbances, particularly in anxiety‐related insomnia, more robust, long‐term clinical trials are needed (Babson et al. 2017).

Numerous clinical studies have explored the role of individual nutrients, dietary patterns, and functional foods in modulating sleep parameters. For example, supplementation with melatonin‐rich foods such as tart cherries has consistently demonstrated modest improvements in sleep latency and efficiency in both healthy populations and individuals with insomnia (Pigeon et al. 2010; Howatson et al. 2012).

Similarly, trials investigating magnesium supplementation in older adults and individuals with insomnia have reported enhanced subjective sleep quality and increased sleep duration (Abbasi et al. 2012). Magnesium's regulatory effect on the GABAergic system may partly explain these improvements. Zinc supplementation has also been associated with shorter sleep onset latency and better overall sleep efficiency, particularly when combined with other micronutrients like melatonin and magnesium (Rondanelli et al. 2011).

Dietary interventions, such as adherence to a Mediterranean diet, have shown associations with better sleep quality, longer sleep duration, and lower incidence of insomnia symptoms (St‐Onge et al. 2016). The Mediterranean diet's high content of anti‐inflammatory compounds, fiber, and omega‐3 fatty acids may mediate these positive effects through modulation of systemic inflammation and circadian gene expression.

However, not all studies yield uniformly positive results. Variations in study design, sample size, duration of interventions, and assessment tools (subjective versus objective measures of sleep) contribute to inconsistent findings. Moreover, most studies focus on short‐term outcomes, limiting conclusions about long‐term benefits and sustainability.

Several limitations impede a comprehensive understanding of how nutritional interventions influence sleep: Heterogeneity of Study Populations: Many trials include diverse populations varying in age, gender, baseline sleep status, and comorbidities, making it difficult to generalize findings.Lack of Standardized Outcome Measures: Studies often rely heavily on subjective sleep diaries or questionnaires rather than objective measures such as polysomnography or actigraphy.Short Follow‐up Duration: Many interventions span only a few weeks, failing to capture the long‐term effects of dietary changes on sleep regulation.Complexity of Nutritional Factors: Isolating the effect of a single nutrient or food item is challenging due to interactions between various dietary components and lifestyle factors.

Future clinical research must address these limitations to establish stronger causal relationships and inform evidence‐based nutritional guidelines for sleep health.

Recognizing the complexity of sleep regulation, future studies are moving toward integrative, multidisciplinary approaches: Personalized Nutrition for Sleep Disorders: Advances in nutrigenomics and metabolomics are enabling tailored dietary interventions based on individual genetic predispositions, microbiome profiles, and metabolic phenotypes (Sharma and Nelson 2024; BaHammam and Pirzada 2023; Sojeong and Heon‐Jeong 2020; Potter et al. 2016; McEwen and Karatsoreos 2015). For instance, genetic variations in clock genes or melatonin receptor genes may influence responsiveness to certain dietary interventions.Chrononutrition and Timing of Intake: The timing of food intake profoundly affects circadian rhythms. Emerging studies suggest that time‐restricted feeding, aligning meals with circadian phases, and evening consumption of melatonin‐rich foods can optimize sleep–wake cycles (Pot et al. 2016).Gut‐Brain Axis Modulation: Given the mounting evidence linking gut microbiota composition with sleep regulation, interventions targeting the microbiome through probiotics, prebiotics, or fiber‐rich diets are gaining interest (Lin et al. 2024; Wu et al. 2023; Zhe Wang et al. 2022)Multi‐Ingredient Approaches: Instead of focusing solely on single nutrients, future strategies may explore the synergistic effects of combined bioactive compounds (e.g., omega‐3 fatty acids with polyphenols) to amplify benefits on sleep quality.

To advance nutritional sleep medicine, there is an urgent need for: Large, multicenter randomized controlled trials (RCTs) with standardized protocols. Longer intervention durations to assess the sustainability of sleep improvements. Inclusion of diverse populations, particularly vulnerable groups such as shift workers, adolescents, and older adults. Use of objective sleep assessment tools (e.g., polysomnography, actigraphy) alongside validated subjective questionnaires. Exploration of underlying mechanisms via biomarker analyses, hormonal profiling, and neuroimaging studies.

In conclusion, while current evidence supports the role of diet and specific nutrients in sleep modulation, robust, high‐quality research is needed to translate these findings into clinical practice and public health recommendations.

Despite increasing evidence linking nutrition and sleep, several methodological limitations constrain interpretation. First, most data rely on self‐reported dietary intake and sleep quality, which introduces recall and reporting bias. Second, confounding factors such as physical activity, stress, caffeine use, medication, and underlying health conditions often complicate causal inference. Third, interindividual differences in chronotype, age, gender, and genetic polymorphisms (e.g., in CLOCK or PER3 genes) may modify dietary effects on sleep. Finally, short study durations and small sample sizes limit external validity. Future research should standardize assessment tools, integrate objective sleep measures (e.g., actigraphy, polysomnography), and consider these variables to improve reliability.

Several broad dietary strategies have emerged from current research that can be recommended to the general population for promoting better sleep: Increase Intake of Sleep‐Supportive Nutrients: Ensuring adequate consumption of key nutrients such as magnesium, zinc, omega‐3 fatty acids, and tryptophan through a balanced diet can support neurotransmitter synthesis and circadian regulation (Hosseini et al. 2018; Rondanelli et al. 2011).Adopt Anti‐Inflammatory Dietary Patterns: Emphasizing Mediterranean or plant‐based diets, which are rich in antioxidants, fiber, and anti‐inflammatory compounds, may help improve sleep quality by reducing systemic inflammation and oxidative stress (St‐Onge et al. 2016).Mind the Timing of Meals (Chrononutrition): Aligning eating patterns with circadian rhythms—such as consuming larger meals earlier in the day and avoiding heavy meals close to bedtime—can optimize sleep onset and efficiency (Pot et al. 2016).Limit Sleep‐Disrupting Foods: Reducing intake of caffeine, alcohol, and high‐glycemic index foods in the evening is important for preventing sleep fragmentation and disturbances (Gardiner et al. 2023; O'Callaghan et al. 2018).

These general recommendations serve as a foundation; however, a "one‐size‐fits‐all" approach may not be adequate for addressing individual variability in sleep needs and responses to dietary interventions.

The concept of personalized nutrition—tailoring dietary advice to individual biological, genetic, and lifestyle factors—offers great promise in managing sleep disorders. Genetic Factors: Polymorphisms in genes involved in circadian regulation (e.g., CLOCK, PER3), melatonin production (e.g., MTNR1B), and nutrient metabolism (e.g., FADS1 for omega‐3 fatty acid synthesis) can influence sleep patterns and responsiveness to dietary interventions (Lopez‐Minguez et al. 2019). Nutrigenetic testing may help identify individuals who would benefit from specific nutrients or chrononutrition strategies.Metabolic Health Status: Conditions such as obesity, insulin resistance, and metabolic syndrome are closely linked with sleep apnea and other sleep disorders. Personalized interventions that target weight reduction and glycemic control through tailored diets can significantly improve sleep outcomes (Chaput and Tremblay 2012).Gut Microbiota Profiling: Given the emerging evidence connecting gut microbiome composition with sleep quality, microbiota‐targeted interventions (e.g., personalized probiotic or prebiotic therapy) could be optimized based on an individual's gut microbial profile (Lin et al. 2024; Wu et al. 2023; Zhe Wang et al. 2022).Lifestyle and Behavioral Factors: Sleep hygiene practices (Sleep hygiene refers to a set of behavioral and environmental practices that promote consistent, high‐quality sleep, including maintaining regular sleep–wake schedules, optimizing the sleep environment, and minimizing stimulants or screen exposure before bedtime), physical activity levels, stress management, and work schedules (e.g., shift work) all interact with dietary patterns. Personalized plans should integrate these behavioral aspects to maximize effectiveness (Chaput et al. 2023; Boege et al. 2021; Scheer et al. 2013).

Emerging research supports the potential for personalized nutrition strategies in sleep health (Konstantinidou and Jamshed 2024). Genetic variations in circadian rhythm–related genes (e.g., CLOCK, PER2, BMAL1) and nutrient metabolism (e.g., FADS1 for omega‐3 synthesis) can influence responsiveness to dietary interventions (Özata Uyar et al. 2024; Franzago et al. 2023). Chronotype differences—morning vs. evening preference—also modify metabolic responses to meal timing, a concept central to Chrononutrition (Campos et al. 2025). Personalized approaches incorporating genetic testing, metabolic profiling, and lifestyle factors could enable precision dietary recommendations for specific sleep disorders such as insomnia, sleep apnea, and delayed sleep phase syndrome.

Technological advancements, including wearable sleep trackers, digital food diaries, and machine‐learning‐based predictive models, are paving the way for highly personalized and dynamic nutrition‐sleep programs (Leota et al. 2025; Pakwan and Kittiphon 2025; Ka et al. 2025; Wang and Boros 2019; Kelley and Kelley 2017). Wearable devices can monitor real‐time sleep metrics, allowing for immediate feedback and dietary adjustments based on sleep responses. Digital health platforms may also integrate genetic, metabolic, and lifestyle data to generate individualized, adaptive nutrition recommendations.

The integration of personalized nutrition into sleep medicine not only has the potential to enhance individual outcomes but also to contribute to preventive strategies at the population level by identifying at‐risk groups early and intervening proactively.

While personalized nutrition approaches are promising, several challenges must be addressed: Cost and Accessibility: Genetic testing and advanced microbiome analysis can be expensive and may not be readily available in all healthcare settings.Data Privacy and Ethical Concerns: Managing sensitive genetic and health data requires strict privacy protections and ethical oversight.Need for Evidence‐Based Algorithms: Personalized nutrition recommendations must be based on robust scientific evidence to ensure safety and efficacy.

Addressing these challenges will be essential for the successful integration of personalized dietary interventions into mainstream clinical practice for sleep health management.

Translating current evidence into actionable dietary strategies is essential for clinicians and individuals seeking to improve sleep quality through nutrition. While dietary responses vary by genetics, lifestyle, and chronotype, several foods and nutrients have demonstrated consistent associations with enhanced sleep duration, efficiency, and circadian stability. Table 5 summarizes practical, evidence‐based dietary recommendations derived from clinical and observational studies, emphasizing whole‐food sources and sustainable approaches to improving sleep health.