The association between dietary tryptophan intake and migraine

Tryptophan metabolism in children with migraine: The role of kynurenine pathway

BACKGROUND

Migraine is a common neurological disorder in children, significantly impacting quality of life and academic performance. The kynurenine pathway, a major metabolic route of tryptophan, plays a critical role in neuroinflammation and neurotransmission, yet its involvement in pediatric migraine remains unexplored. This study aims to investigate alterations in kynurenine pathway metabolites in children with migraine and assess their correlation with headache frequency and severity.

METHODS

A case-control study was conducted including pediatric patients diagnosed with migraine (n = 45) and healthy controls (n = 48). Serum levels of tryptophan (TRP) and its kynurenine pathway metabolites-including kynurenine (KYN), kynurenic acid (KYNA), 3-hydroxykynurenine (3-HK), and 3-hydroxyanthranilic acid (3-HANA)-were quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The Pediatric Migraine Disability Assessment (PedMIDAS) scores were used to evaluate the functional impact of migraine. Statistical analyses included comparisons between groups and correlation assessments between metabolite levels and clinical parameters.

RESULTS

KYN, KYNA, and the KYN/TRP ratio were significantly higher in the migraine group compared to controls (p < 0.05). KYNA/3-HK ratios showed a negative correlation with headache frequency and PedMIDAS scores, whereas 3-HK levels were positively correlated with PedMIDAS scores. Receiver operating characteristic curve analysis identified KYN as a potential biomarker for distinguishing migraine patients from controls, with a sensitivity of 86.7 % and specificity of 45.8 % at a cutoff value of 1415.

CONCLUSION

This study is the first to evaluate kynurenine pathway metabolites in pediatric migraine. The findings suggest that alterations in the tryptophan-kynurenine pathway, particularly increased KYN and KYNA levels, may serve as compensatory mechanisms in migraine pathophysiology. Future studies should explore the therapeutic implications of targeting the kynurenine pathway in pediatric migraine treatment.

Metabolic Dysfunction and Dietary Interventions in Migraine Management: The Role of Insulin Resistance and Neuroinflammation-A Narrative and Scoping Review

INTRODUCTION

Migraine is a prevalent neurological disorder characterized by recurrent headaches with autonomic and neurological symptoms, significantly impacting quality of life globally. Its pathogenesis involves genetic, neurological, inflammatory, and metabolic factors, with insulin resistance and metabolic dysfunction increasingly recognized as important contributors. Historically, it has been known that certain foods can trigger migraine attacks, which led for many years to the recommendation of elimination diets-now understood to primarily target histamine-rich foods. Over the past two decades, attention has shifted toward underlying metabolic disturbances, leading to the development of dietary approaches specifically aimed at addressing these dysfunctions.

METHODS

A scoping literature review was conducted using PubMed and Embase to evaluate the relationships among migraine, insulin-related mechanisms, neurogenic inflammation, and dietary interventions. Initial searches focused on "MIGRAINE AND (neurogenic inflammation)" (2019-15 April 2025), followed by expanded searches from 1950 onward using terms such as "MIGRAINE AND (insulin, insulin resistance, hyperinsulinism)", and "MIGRAINE AND (diet, dietary, nutrition, nutritional)". A specific search also targeted "(INSULIN OR insulin resistance OR hyperinsulinism) AND (neurogenic inflammation)". Abstracts were screened, full texts were retrieved, and duplicates or irrelevant publications were excluded. No filters were applied by article type or language. Systematic reviews and meta-analyses were prioritized when available.

RESULTS

Migraine pathogenesis involves trigeminovascular system activation, neurogenic inflammation mediated by CGRP and PACAP, immune dysregulation, mast cell activation, and cortical spreading depression (CSD). Emerging evidence highlights significant associations between migraine, insulin resistance, and hyperinsulinism. Hyperinsulinism contributes to migraine through TRPV1 sensitization, increased CGRP release, oxidative stress, mitochondrial dysfunction, and systemic inflammation. Metabolic dysfunction, including obesity and insulin resistance, exacerbates migraine severity and frequency. Dietary interventions, particularly anti-inflammatory, Mediterranean, and ketogenic diets, show promise in reducing migraine frequency and severity through mechanisms involving reduced inflammation, oxidative stress, improved mitochondrial function, and glucose metabolism stabilization.

CONCLUSIONS

The interplay between insulin resistance, metabolic dysfunction, and neuroinflammation is crucial in migraine pathophysiology. Targeted dietary interventions, including ketogenic and Mediterranean diets, demonstrate significant potential in managing migraines, emphasizing the need for personalized nutritional strategies to optimize therapeutic outcomes.

Neuroanatomical evidence and a mouse calcitonin gene-related peptide model in line with human functional magnetic resonance imaging data support the involvement of peptidergic Edinger-Westphal nucleus in migraine

ABSTRACT

The urocortin 1 (UCN1)-expressing centrally projecting Edinger-Westphal (EWcp) nucleus is influenced by circadian rhythms, hormones, stress, and pain, all known migraine triggers. Our study investigated EWcp's potential involvement in migraine. Using RNAscope in situ hybridization and immunostaining, we examined the expression of calcitonin gene-related peptide (CGRP) receptor components in both mouse and human EWcp and dorsal raphe nucleus (DRN). Tracing study examined connection between EWcp and the spinal trigeminal nucleus (STN). The intraperitoneal CGRP injection model of migraine was applied and validated by light-dark box, and von Frey assays in mice, in situ hybridization combined with immunostaining, were used to assess the functional-morphological changes. The functional connectivity matrix of EW was examined using functional magnetic resonance imaging in control humans and interictal migraineurs. We proved the expression of CGRP receptor components in both murine and human DRN and EWcp. We identified a direct urocortinergic projection from EWcp to the STN. Photophobic behavior, periorbital hyperalgesia, increased c-fos gene-encoded protein immunoreactivity in the lateral periaqueductal gray matter and trigeminal ganglia, and phosphorylated c-AMP-responsive element binding protein in the STN supported the efficacy of CGRP-induced migraine-like state. Calcitonin gene-related peptide administration also increased c-fos gene-encoded protein expression, Ucn1 mRNA, and peptide content in EWcp/UCN1 neurons while reducing serotonin and tryptophan hydroxylase-2 levels in the DRN. Targeted ablation of EWcp/UCN1 neurons induced hyperalgesia. A positive functional connectivity between EW and STN as well as DRN has been identified by functional magnetic resonance imaging. The presented data strongly suggest the regulatory role of EWcp/UCN1 neurons in migraine through the STN and DRN with high translational value.

Gamma-aminobutyric acid and glutamate/glutamine levels in the dentate nucleus and periaqueductal gray in new daily persistent headache: a magnetic resonance spectroscopy study

BACKGROUND

Magnetic resonance spectroscopy (MRS) studies have indicated that the imbalance between gamma-aminobutyric acid (GABA) and glutamate/glutamine (Glx) levels was the potential cause of migraine development. However, the changes in the GABA and Glx levels in patients with New daily persistent headache (NDPH) remain unclear. This study aimed to investigate the changes in GABA and Glx levels in the periaqueductal gray (PAG) and dentate nucleus (DN) in patients with NDPH using the MEGA-PRESS sequence.

METHODS

Twenty-one NDPH patients and 22 age- and sex-matched healthy controls (HCs) were included and underwent a 3.0T MRI examination, using the MEGA-PRESS sequence to analyze GABA and Glx levels of PAG and DN. The correlations between these neurotransmitter levels and clinical characteristics were also analyzed.

RESULTS

There were no significant differences in the GABA+/Water, GABA+/Cr, Glx/Water, and Glx/Cr levels in both PAG and DN between the two groups (all p > 0.05). Moderate-severe NDPH patients had lower levels of Glx/Water (p = 0.034) and Glx/Cr (p = 0.012) in DN than minimal-mild NDPH patients. In patients with NDPH, higher Glx/Water levels in the PAG (r=-0.471, p = 0.031, n = 21) and DN (r=-0.501, p = 0.021, n = 21) and higher Glx/Cr levels in DN (r=-0.483, p = 0.026, n = 21) were found to be correlated with lower Visual Analogue Scale scores. Additionally, a positive correlation was observed between the GABA+/Cr levels in the DN and the Generalized Anxiety Disorder-7 scores (r = 0.519, p = 0.039, n = 16).

CONCLUSIONS

The results of this study indicated that the GABA and Glx levels in the PAG and DN may not be the primary contributor to the development of NDPH. The correlations between certain clinical scales and the neurotransmitter levels may be derived from the NDPH related symptoms.

Sleep Patterns and Tryptophan Consumption among Students at Spanish Universities: The Unihcos Project

The objective of this cross-sectional study was to explore sleep patterns and the potential relationship between sleep and tryptophan intake among Spanish university students. A total of 11,485 students self-reported their sleep and dietary patterns and habits. Tryptophan intake was calculated using a food intake matrix and results were presented as quartiles of total intake. Short sleep duration prevalence was 51.0%, with males exhibiting a significantly higher frequency. A total of 55.0% of participants presented inadequate sleep efficiency, with males again presenting a higher rate. Median tryptophan intake was 692.16 ± 246.61 mg/day, 731.84 ± 246.86 mg/day in males and 677.24 ± 244.87 mg/day in females (p = 0.001). Dietary tryptophan intake below the first quartile (<526.43 mg/day) was associated with a higher risk of short sleep duration in males (1.26; 95%CI: 1.02-1.55) and females (1.19; 95%CI: 1.05-1.34) and with the Athens Insomnia Scale insomnia in males (2.56; 95%CI: 1.36-4.82) and females (1.47; 95%CI: 1.10-2.05). Regarding academic specializations, females in the humanities field showed a higher risk of Athens Insomnia Scale insomnia due to low tryptophan intake (Q1: 3.15; 95% CI: 1.04-9.55 and Q2: 3.41; 95%CI: 1.01-11.5). In summary, lower tryptophan consumption appears to be associated with poorer sleep quality in Spanish university students; however, other social factors affecting students may also influence sleep quality. These findings have important implications for nutritional recommendations aimed at enhancing tryptophan intake to improve sleep quality.

The Brain, the Eating Plate, and the Gut Microbiome: Partners in Migraine Pathogenesis

This review summarizes the relationship between diet, the gut microbiome, and migraine. Key findings reveal that certain dietary factors, such as caffeine and alcohol, can trigger migraine, while nutrients like magnesium and riboflavin may help alleviate migraine symptoms. The gut microbiome, through its influence on neuroinflammation (e.g., vagus nerve and cytokines), gut-brain signaling (e.g., gamma-aminobutyric acid), and metabolic function (e.g., short-chain fatty acids), plays a crucial role in migraine susceptibility. Migraine can also alter eating behaviors, leading to poor nutritional choices and further exacerbating the condition. Individual variability in diet and microbiome composition highlights the need for personalized dietary and prebiotic interventions. Epidemiological and clinical data support the effectiveness of tailored nutritional approaches, such as elimination diets and the inclusion of beneficial nutrients, in managing migraine. More work is needed to confirm the role of prebiotics, probiotics, and potentially fecal microbiome translation in the management of migraine. Future research should focus on large-scale studies to elucidate the underlying mechanisms of bidirectional interaction between diet and migraine and develop evidence-based clinical guidelines. Integrating dietary management, gut health optimization, and lifestyle modifications can potentially offer a holistic approach to reducing migraine frequency and severity, ultimately improving patient outcomes and quality of life.

Healthy eating index 2015 might be associated with migraine headaches: Results from a Case-Control study

Migraine headaches are the most prevalent disabling primary headaches, affecting individuals at an active age. Dietary interventions are considered low-cost and practical approaches to migraine prophylaxis. Hence, the present study aimed to assess the association between adherence to the Healthy Eating Index 2015 (HEI-2015) and migraine headaches. The present case-control study was conducted on 476 newly diagnosed adults with migraine headaches, based on the International Classification of Headache Disorders 3rd edition (ICHDIII criteria(, and 512 healthy controls. Participants' dietary intakes were collected using a validated, 168-item semi-quantitative food frequency questionnaire (FFQ). The association between HEI-2015 and migraine headaches was assessed using logistic regression models. Although the trend was not statistically significant, being in the 4th quantile of the HEI-2015 was associated with about 50% lower odds of migraine headaches in both primary (adjusted for age and gender) (odds ratios (OR): 0.51, 95% confidence intervals (CI): 0.33, 0.78) and fully adjusted models (additionally adjusted for body mass index (BMI) and total calories) (adjusted OR: 0.50, 95%CI: 0.32, 0.77). Intriguingly, the odds of migraine headaches were significantly higher in those in the last quantile of "Total Fruits," which is equal to more than 237 g per 1000 kcal (aOR: 2.96, 95%CI: 1.99, 4.41) and "Whole Fruits," which is equal to more than 233 g per 1000 kcal (aOR: 2.90, 95%CI: 1.94, 4.31). Similarly, higher intakes of "Dairy," which is equal to more than 138 g per 1000 kcal (aOR: 2.66, 95%CI: 1.71, 4.14), and "Total Protein Foods," which is equal to more than 259 g per 1000 kcal (aOR: 2.41, 95%CI: 1.58, 3.70), were associated with higher odds of migraine headaches. The current study revealed an indirect association between HEI-2015 and its components, including "Greens and Beans," "Whole Grains," "Refined Grains," and "Added Sugars" and lower odds of migraine headaches.

Migraine and the microbiota. Can probiotics be beneficial in its prevention? - a narrative review

Migraine is a recurrent disease of the central nervous system that affects an increasing number of people worldwide causing a continuous increase in the costs of treatment. The mechanisms underlying migraine are still unclear but recent reports show that people with migraine may have an altered composition of the intestinal microbiota. It is well established that the gut-brain axis is involved in many neurological diseases, and probiotic supplementation may be an interesting treatment option for these conditions. This review collects data on the gastrointestinal and oral microbiota in people suffering from migraine and the use of probiotics as a novel therapeutic approach in its treatment.

The kynurenine pathway of tryptophan metabolism in abdominal migraine in children - A therapeutic potential?

BACKGROUND

Abdominal migraine (AM) is a clinical diagnosis specified by Rome IV and ICHD III as a functional gastrointestinal disease (FGID) and a migraine associated syndrome, respectively. Abdominal migraine in childhood and adolescence may continue with migraine headaches in adulthood. This disease is undiagnosed and undertreated, and thus far the FDA has not approved any drug for AM treatment. It was shown that changes in the kynurenine (KYN) pathway of tryptophan (TRP) metabolism played an important role in the pathogenesis and treatment of FIGDs and associated mood disorders. Changes in the KYN pathway were shown in migraine and therefore it may be involved in AM pathogenesis.

FINDINGS

Abdominal migraine reflects an impairment in the communication within the gut-brain axis. Treatment approaches in AM are based on the experience of physicians, presenting personal rather than evidence-based practice, including efficacy of some drugs in adult migraine. Non-pharmacological treatment of AM is aimed at preventing or ameliorating AM triggers and is based on the STRESS mnemonic. Metabolic treatments with riboflavin and coenzyme Q10 were effective in several cases of pediatric migraine, but in general, results on metabolic treatment in migraine in children are scarce and nonconclusive. Modulations within the KYN pathway of TRP metabolism induced by changes in TRP content in the diet, may ameliorate FGIDs and support their pharmacological treatment. Pharmacological manipulations of brain KYNs in animals have brought promising results for clinical applications. Obese children show a higher headache prevalence and may be especially predisposed to AM, and KYN metabolites showed an alternated distribution in obese individuals as compared with their normal-weight counterparts.

CONCLUSIONS

In conclusion, controlled placebo-based clinical trials with dietary manipulation to adjust the amount of the product of the KYN pathway of TRP metabolism are justified in children and adolescents with AM, especially those with coexisting obesity. Further preclinical studies are needed to establish details of these trials.

All Roads Lead to the Gut: The Importance of the Microbiota and Diet in Migraine

Migraine, a prevalent neurological condition and the third most common disease globally, places a significant economic burden on society. Despite extensive research efforts, the precise underlying mechanism of the disease remains incompletely comprehended. Nevertheless, it is established that the activation and sensitization of the trigeminal system are crucial during migraine attacks, and specific substances have been recognized for their distinct involvement in the pathomechanism of migraine. Recently, an expanding body of data indicates that migraine attacks can be prevented and treated through dietary means. It is important to highlight that the various diets available pose risks for patients without professional guidance. This comprehensive overview explores the connection between migraine, the gut microbiome, and gastrointestinal disorders. It provides insight into migraine-triggering foods, and discusses potential diets to help reduce the frequency and severity of migraine attacks. Additionally, it delves into the benefits of using pre- and probiotics as adjunctive therapy in migraine treatment.

Excitation-Inhibition Imbalance in Migraine: From Neurotransmitters to Brain Oscillations

Migraine is among the most common and debilitating neurological disorders typically affecting people of working age. It is characterised by a unilateral, pulsating headache often associated with severe pain. Despite the intensive research, there is still little understanding of the pathophysiology of migraine. At the electrophysiological level, altered oscillatory parameters have been reported within the alpha and gamma bands. At the molecular level, altered glutamate and GABA concentrations have been reported. However, there has been little cross-talk between these lines of research. Thus, the relationship between oscillatory activity and neurotransmitter concentrations remains to be empirically traced. Importantly, how these indices link back to altered sensory processing has to be clearly established as yet. Accordingly, pharmacologic treatments have been mostly symptom-based, and yet sometimes proving ineffective in resolving pain or related issues. This review provides an integrative theoretical framework of excitation-inhibition imbalance for the understanding of current evidence and to address outstanding questions concerning the pathophysiology of migraine. We propose the use of computational modelling for the rigorous formulation of testable hypotheses on mechanisms of homeostatic imbalance and for the development of mechanism-based pharmacological treatments and neurostimulation interventions.

Exploring the Tryptophan Metabolic Pathways in Migraine-Related Mechanisms

Migraine is a complex neurovascular disorder, which causes intense socioeconomic problems worldwide. The pathophysiology of disease is enigmatic; accordingly, therapy is not sufficient. In recent years, migraine research focused on tryptophan, which is metabolized via two main pathways, the serotonin and kynurenine pathways, both of which produce neuroactive molecules that influence pain processing and stress response by disturbing neural and brain hypersensitivity and by interacting with molecules that control vascular and inflammatory actions. Serotonin has a role in trigeminal pain processing, and melatonin, which is another product of this pathway, also has a role in these processes. One of the end products of the kynurenine pathway is kynurenic acid (KYNA), which can decrease the overexpression of migraine-related neuropeptides in experimental conditions. However, the ability of KYNA to cross the blood-brain barrier is minimal, necessitating the development of synthetic analogs with potentially better pharmacokinetic properties to exploit its therapeutic potential. This review summarizes the main translational and clinical findings on tryptophan metabolism and certain neuropeptides, as well as therapeutic options that may be useful in the prevention and treatment of migraine.

Citalopram Neuroendocrine Challenge Shows Altered Tryptophan and Kynurenine Metabolism in Migraine

Altered tryptophan (TRP) metabolism may have an important role in migraine susceptibility through its main metabolites, serotonin and kynurenine (KYN). Both affect pain processing and stress response by interfering with neural and brain hypersensitivity and by interacting with chemokines and cytokines that control vascular and inflammatory processes. The involvement of these pathways in migraine has been widely studied, but acute citalopram neuroendocrine challenge on TRP metabolism and cytokine profile has not been investigated yet. In our study, females with episodic migraine without aura and healthy controls were studied before and after acute citalopram or placebo in a double-blind setting. At baseline, increased TRP/large neutral amino acid (LNAA) ratio and decreased RANTES chemokine concentration were detected in migraine patients compared to controls. The challenge induced a significant increase in TRP, KYN, and TRP/LNAA in healthy controls, but not in migraine patients. Furthermore, migraine attack frequency negatively correlated with KYN/TRP ratio and positively correlated with the neuroendocrine-challenge-induced KYN concentration increase. Our results support a decreased breakdown of TRP via KYN pathway and a failure to modulate TRP–KYN pathway during citalopram-induced acute stress together with an increased vascular sensitivity in migraine. These mechanisms may provide useful drug targets for future drug development.

Migraine signaling pathways: amino acid metabolites that regulate migraine and predispose migraineurs to headache

Migraine is a common, debilitating disorder for which attacks typically result in a throbbing, pulsating headache. Although much is known about migraine, its complexity renders understanding the complete etiology currently out of reach. However, two important facts are clear, the brain and the metabolism of the migraineur differ from that of the non-migraineur. This review centers on the altered amino acid metabolism in migraineurs and how it helps define the pathology of migraine.

Association of plasma tryptophan concentration with periaqueductal gray matter functional connectivity in migraine patients

Altered periaqueductal gray matter (PAG) functional connectivity contributes to brain hyperexcitability in migraine. Although tryptophan modulates neurotransmission in PAG projections through its metabolic pathways, the effect of plasma tryptophan on PAG functional connectivity (PAG-FC) in migraine has not been investigated yet. In this study, using a matched case-control design PAG-FC was measured during a resting-state functional magnetic resonance imaging session in migraine without aura patients (n = 27) and healthy controls (n = 27), and its relationship with plasma tryptophan concentration (TRP) was assessed. In addition, correlations of PAG-FC with age at migraine onset, migraine frequency, trait-anxiety and depressive symptoms were tested and the effect of TRP on these correlations was explored. Our results demonstrated that migraineurs had higher TRP compared to controls. In addition, altered PAG-FC in regions responsible for fear-cascade and pain modulation correlated with TRP only in migraineurs. There was no significant correlation in controls. It suggests increased sensitivity to TRP in migraine patients compared to controls. Trait-anxiety and depressive symptoms correlated with PAG-FC in migraine patients, and these correlations were modulated by TRP in regions responsible for emotional aspects of pain processing, but TRP did not interfere with processes that contribute to migraine attack generation or attack frequency.

Kynurenine Pathway of Tryptophan Metabolism in Migraine and Functional Gastrointestinal Disorders

Migraine, the leading cause of disability in the population aged below 50, is associated with functional gastrointestinal (GI) disorders (FGIDs) such as functional nausea, cyclic vomiting syndrome, and irritable bowel syndrome (IBS). Conversely, changes in intestinal GI transit may cause diarrhea or constipation and are a component of the autonomic symptoms associated with pre- and post-dorsal phases of migraine attack. These mutual relationships provoke a question on a common trigger in migraine and FGIDs. The kynurenine (l-kyn) pathway (KP) is the major route for l-tryptophan (l-Trp) metabolism and transforms l-Trp into several neuroactive compounds. Changes in KP were reported in both migraine and FGIDs. Migraine was largely untreatable, but several drugs approved lately by the FDA, including monoclonal antibodies for calcitonin gene-related peptide (CGRP) and its receptor, create a hope for a breakthrough in migraine treatment. Derivatives of l-kyn were efficient in pain relief with a mechanism including CGRP inhibition. KP products are important ligands to the aryl hydrocarbon receptor (AhR), whose activation is implicated in the pathogenesis of GI and migraine. Toll-like receptors (TLRs) may play a role in migraine and IBS pathogeneses, and KP metabolites detected downstream of TLR activation may be an IBS marker. The TLR4 signaling was observed in initiating and maintaining migraine-like behavior through myeloid differentiation primary response gene 88 (MyD88) in the mouse. The aim of this review is to justify the view that KP modulation may provide common triggers for migraine and FGIDs with the involvement of TLR, AhR, and MyD88 activation.

Clinical relevance of depressed kynurenine pathway in episodic migraine patients: potential prognostic markers in the peripheral plasma during the interictal period

Background

Altered glutamatergic neurotransmission and neuropeptide levels play a central role in migraine pathomechanism. Previously, we confirmed that kynurenic acid, an endogenous glutamatergic antagonist, was able to decrease the expression of pituitary adenylate cyclase-activating polypeptide 1–38, a neuropeptide with known migraine-inducing properties. Hence, our aim was to reveal the role of the peripheral kynurenine pathway (KP) in episodic migraineurs. We focused on the complete tryptophan (Trp) catabolism, which comprises the serotonin and melatonin routes in addition to kynurenine metabolites. We investigated the relationship between metabolic alterations and clinical characteristics of migraine patients.

Methods

Female migraine patients aged between 25 and 50 years (n = 50) and healthy control subjects (n = 34) participated in this study. Blood samples were collected from the cubital veins of subjects (during both the interictal/ictal periods in migraineurs, n = 47/12, respectively). 12 metabolites of Trp pathway were determined by neurochemical measurements (UHPLC-MS/MS).

Results

Plasma concentrations of the most Trp metabolites were remarkably decreased in the interictal period of migraineurs compared to healthy control subjects, especially in the migraine without aura (MWoA) subgroup: Trp (p < 0.025), L-kynurenine (p < 0.001), kynurenic acid (p < 0.016), anthranilic acid (p < 0.007), picolinic acid (p < 0.03), 5-hydroxy-indoleaceticacid (p < 0.025) and melatonin (p < 0.023). Several metabolites showed a tendency to elevate during the ictal phase, but this was significant only in the cases of anthranilic acid, 5-hydroxy-indoleaceticacid and melatonin in MWoA patients. In the same subgroup, higher interictal kynurenic acid levels were identified in patients whose headache was severe and not related to their menstruation cycle. Negative linear correlation was detected between the interictal levels of xanthurenic acid/melatonin and attack frequency. Positive associations were found between the ictal 3-hydroxykynurenine levels and the beginning of attacks, just as between ictal picolinic acid levels and last attack before ictal sampling.

Conclusions

Our results suggest that there is a widespread metabolic imbalance in migraineurs, which manifests in a completely depressed peripheral Trp catabolism during the interictal period. It might act as trigger for the migraine attack, contributing to glutamate excess induced neurotoxicity and generalised hyperexcitability. This data can draw attention to the clinical relevance of KP in migraine.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-021-01239-1.

The Association Between Dietary Acid Load and Odds of Migraine: A Case-Control Survey

INTRODUCTION

It has been shown that a high acid load in the human body can affect inflammatory factors and the nitric oxide pathway. These factors are also thought to play an important role in the initiation of migraine attacks. We have therefore explored the association between dietary acid load and odds of migraine in a case-control study.

METHODS

The migraine group (n = 514, diagnosed according to the International Classification of Headache Disorders 3rd edition [ICHDIII] criteria) was recruited from a tertiary headache clinic. The controls consisted of 582 sex-matched healthy volunteers who were randomly selected from the general population. A validated 168-item semiquantitative food frequency questionnaire was used for dietary intake assessments. Estimation of the dietary acid load was performed using three different measures: potential renal acid load (PRAL) score, net endogenous acid production (NEAP) score, and protein/potassium ratio.

RESULTS

Multivariable logistic regression analysis showed that, in comparison with the lowest tertile, the highest tertile of dietary acid load measures, including PRAL (odds ratio [OR] 7.208, 95% confidence intervals [CI] 3.33-15.55), and NEAP (OR 4.108, 95% CI 1.924-8.774) scores and the protein/potassium ratio (OR 4.127, 95% CI 1.933-8.814), significantly increased the odds of migraine (P value for trend ≤ 0.001).

CONCLUSION

In this study, high dietary acid load was associated with higher odds of migraine. It is therefore possible that restricting dietary acid load could reduce the odds of migraine in susceptible subjects. However, due to the preliminary nature of the current evidence, caution is advised in drawing a definitive conclusion. More well-designed studies are required for a better understanding of this important issue.

To Eat or Not to Eat: A Review of the Relationship between Chocolate and Migraines

Migraine is a chronic disorder with episodic attacks, and patients with a migraine often report that certain factors can trigger their headache, with chocolate being the most popular type of food-based trigger. Many studies have suggested a link between chocolate and headaches; however, the underlying physiological mechanisms are unclear. As premonitory symptoms may herald migraine attacks, a question arises regarding whether eating chocolate before a headache is a consequence of a food craving or indeed a real trigger. Here, we aim to summarize the available evidence on the relationship between chocolate and migraines. All articles concerning this topic published up to January 2020 were retrieved by searching clinical databases, including EMBASE, MEDLINE, PubMed, and Google Scholar. All types of studies have been included. Here, we identify 25 studies investigating the prevalence of chocolate as a trigger factor in migraineurs. Three provocative studies have also evaluated if chocolate can trigger migraine attacks, comparing it to a placebo. Among them, in 23 studies, chocolate was found to be a migraine trigger in a small percentage of participants (ranging from 1.3 to 33), while all provocative studies have failed to find significant differences between migraine attacks induced by eating chocolate and a placebo. Overall, based on our review of the current literature, there is insufficient evidence that chocolate is a migraine trigger; thus, doctors should not make implicit recommendations to migraine patients to avoid it.