Fibromyalgia and nutrition: Therapeutic possibilities?

Neuronutritional Approach to Fibromyalgia Management: A Narrative Review

Fibromyalgia (FM) is a complex and common syndrome characterized by chronic widespread pain, fatigue, sleep disturbances, and various functional symptoms without clear structural or pathological causes. Affecting approximately 1-5% of the global population, with a higher prevalence in women, FM significantly impacts patients' quality of life, often leading to considerable healthcare costs and loss of productivity. Despite its prevalence, the etiology of FM remains elusive, with genetic, environmental, and psychological factors, including nutrition, being implicated. Currently, no universally accepted treatment guidelines exist, and management strategies are often symptomatic. This narrative review explores the potential of a neuronutritional approach to FM management. It synthesizes existing research on the relationship between FM and nutrition, suggesting that dietary interventions could be a promising complementary treatment strategy. Various nutritional interventions, including vitamin D, magnesium, iron, and probiotics supplementation, have shown potential in reducing FM symptoms, such as chronic pain, anxiety, depression, cognitive dysfunction, sleep disturbances, and gastrointestinal issues. Additionally, weight loss has been associated with reduced inflammation and improved quality of life in FM patients. The review highlights the anti-inflammatory benefits of plant-based diets and the low-FODMAPs diet, which have shown promise in managing FM symptoms and related gastrointestinal disorders. Supplements such as vitamin D, magnesium, vitamin B12, coenzyme Q10, probiotics, omega-3 fatty acids, melatonin, S-adenosylmethionine, and acetyl-L-carnitine are discussed for their potential benefits in FM management through various mechanisms, including anti-inflammatory effects, modulation of neurotransmitters, and improvement of mitochondrial function. In conclusion, this review underscores the importance of considering neuronutrition as a holistic approach to FM treatment, advocating for further research and clinical trials to establish comprehensive dietary guidelines and to optimize management strategies for FM patients.

Online Questionnaire with Fibromyalgia Patients Shows Negative Correlations between Disease Severity and Adherence to Mediterranean Diet

Fibromyalgia (FM) is a multidimensional disorder in which intense chronic pain is accompanied by a variety of psychophysical symptoms that impose a burden on the patients' quality of life. Despite the efforts and the recent advancement in research, FM pathogenesis and effective treatment remain unknown. Recently, the possible role of dietary patterns and/or components has been gaining attention. The current study aimed to investigate a potential correlation between adherence to the Mediterranean diet (MedDiet) and FM severity in a sample of Italian FM patients. An online survey was designed, composed of customized questions and validated questionnaires with the aim of investigating the intensity and type of pain, the presence of other psychophysical symptoms, the overall impact of FM, general food and lifestyle habits, and adherence to the MedDiet. The collected responses were analyzed for descriptive statistics, linear regression, and propensity score analyses. The results show that, despite considerable use of pharmaceuticals and supplements, FM participants suffered from a high-severity grade disease. However, those with good adherence to the MedDiet experienced a lower pain intensity and overall FM impact. A propensity score analysis indicates a positive influence of the MedDiet against FM severity, thus unveiling the need for well-designed intervention studies to evaluate the therapeutic potential of different dietary patterns.

Involvement of peripheral mast cells in a fibromyalgia model in mice

Fibromyalgia is a painful disorder of unknown aetiology that presents activation and recruitment of innate immune cells, including mast cells. Efforts have been made to understand its pathogenesis to manage it better. Thus, we explored the involvement of peripheral mast cells in an experimental model of fibromyalgia induced by reserpine. Reserpine (1 mg/kg) was subcutaneously (s.c.) injected once daily in the back of male Swiss mice for three consecutive days. We analysed mechanical and cold allodynia, muscle fatigue and number of mast cell in plantar tissue. The fibromyalgia induction produced mast cell infiltration (i.e., mastocytosis) in the mice's plantar tissue. The depletion of mast cell mediators with the compound 48/80 (0.5-4 mg/kg, intraperitoneal (i.p.)) or the mast cell membrane stabilizer ketotifen fumarate (10 mg/kg, oral route (p.o.) widely (80-90 %) and extensively (from 1 up to 10 days) prevented reserpine-induced mechanical and cold allodynia and muscle fatigue. Compound 48/80 also prevented the reserpine-induced mastocytosis. Finally, we demonstrated that PAR-2, 5-HT2A, 5-HT3, H1, NK1 and MrgprB2 receptors, expressed in neuronal or mast cells, seem crucial to mediate fibromyalgia-related cardinal symptoms since antagonists or inhibitors of these receptors (gabexate (10 mg/kg, s.c.), ENMD-1068 (10 mg/kg, i.p.), ketanserin (1 mg/kg, i.p.), ondansetron (1 mg/kg, p.o.), promethazine (1 mg/kg, i.p.), and L733,060 (5 mg/kg, s.c.), respectively) transiently reversed the reserpine-induced allodynia and fatigue. The results indicate that mast cells mediate painful and fatigue behaviours in this fibromyalgia model, representing potential therapy targets to treat fibromyalgia syndrome.

Nutrition and Chronobiology as Key Components of Multidisciplinary Therapeutic Interventions for Fibromyalgia and Associated Chronic Fatigue Syndrome: A Narrative and Critical Review

Fibromyalgia (FM) is often accompanied by chronic fatigue syndrome (CFS). It is a poorly understood disorder that mainly affects women and leads to chronic pain, fatigue, and insomnia, among other symptoms, which decrease quality of life. Due to the inefficiency of current pharmacological treatments, increasing interest is being directed towards non-pharmacological multicomponent therapies. However, nutrition and chronobiology are often overlooked when developing multicomponent therapies. This narrative and critical review explore the relevance of nutritional and chronobiological strategies in the therapeutic management of FM and the often-associated CFS. Reviewed literature offers scientific evidence for the association of dietary habits, nutrient levels, body composition, gut microbiota imbalance, chronobiological alterations, and their interrelation with the development and severity of symptoms. This review highlights the key role of nutrition and chronobiology as relevant and indispensable components in a multidisciplinary approach to FM and CFS.

Diet and Lifestyle Modifications for Fibromyalgia

Fibromyalgia (FM) is a complex, widespread pain disorder characterized by symptoms such as fatigue, sleep deprivation, mental fog, mood swings, and headaches. Currently, there are only three FDA-approved medications for FM patients: duloxetine, milnacipran, and pregabalin, with outcomes frequently being inadequate. This research team aims to investigate the effects of diet and lifestyle modifications on FM, with emphasis on anti-inflammatory diet, antioxidants, and gluten-free diets, as well as supplementation with Magnesium, CQ10, and Vitamin D, microbiome, sleep, exercise, and cognitive behavioral therapy. We reviewed the pathophysiology of certain foods that can be proinflammatory with the release of cytokines leading to activation of pain, fatigue and aggravation of the majority of Fibromyalgia symptoms. A literature review was performed by identifying FM articles published between 1994 and 2022 via PubMed and EMBASE databases, with particular emphasis on randomized controlled trials, meta-analysis, and evidence-based treatment guidelines. This review article was completed by a comprehensive narrative review process, in which our team systematically examined relevant scientific literature to provide a comprehensive overview of the significant role that diet and other lifestyle modifications play in mediating symptoms of Fibromyalgia. We propose that diet modifications and lifestyle changes, such as sleep, exercise, and weight loss, can be important steps in managing FM.

Melatonin as a Coadjuvant in the Treatment of Patients with Fibromyalgia

Fibromyalgia syndrome (FMS) is a chronic widespread pain syndrome that is accompanied by fatigue, sleep disturbances, anxiety, depression, lack of concentration, and neurocognitive impairment. As the currently available drugs are not completely successful against these symptoms and frequently have several side effects, many scientists have taken on the task of looking for nonpharmacological remedies. Many of the FMS-related symptoms have been suggested to be associated with an altered pattern of endogenous melatonin. Melatonin is involved in the regulation of several physiological processes, including circadian rhythms, pain, mood, and oxidative as well as immunomodulatory balance. Preliminary clinical studies have propounded that the administration of different doses of melatonin to patients with FMS can reduce pain levels and ameliorate mood and sleep disturbances. Moreover, the total antioxidant capacity, 6-sulfatoxymelatonin and urinary cortisol levels, and other biological parameters improve after the ingestion of melatonin. Recent investigations have proposed a pathophysiological relationship between mitochondrial dysfunction, oxidative stress, and FMS by looking at certain proteins involved in mitochondrial homeostasis according to the etiopathogenesis of this syndrome. These improvements exert positive effects on the quality of life of FMS patients, suggesting that the use of melatonin as a coadjuvant may be a successful strategy for the management of this syndrome.

Effectiveness and health benefits of a nutritional, chronobiological and physical exercise primary care intervention in fibromyalgia and chronic fatigue syndrome: SYNCHRONIZE + mixed-methods study protocol

INTRODUCTION

Chronic pain, fatigue and insomnia are classic symptoms of fibromyalgia (FM) and chronic fatigue syndrome (CFS) and seriously affect quality of life. Nutrition and chronobiology are often overlooked in multicomponent approach despite their potential. This study aims to evaluate the effectiveness of a multidisciplinary group intervention based on nutrition, chronobiology, and physical exercise in the improvement of lifestyle and quality of life in FM and CFS.

METHODS

Mixed-methods study based on a randomized clinical trial and qualitative analysis with a descriptive phenomenological approach. The study will be conducted in primary care in Catalonia. The control group will follow the usual clinical practice and the intervention group the usual practice plus the studied intervention (12 hours over 4 days). The intervention based on nutrition, chronobiology and physical exercise will be designed considering participants' opinions as collected in 4 focus groups. To evaluate effectiveness, EuroQol-5D, multidimensional fatigue inventory, VAS pain, Pittsburgh Sleep Quality Index, erMEDAS-17, biological rhythms interview of assessment in neuropsychiatry, REGICOR-Short, FIQR and Hospital Anxiety and Depression Scale questionnaires will be collected at baseline, and at 1, 3, 6, and 12 months post-intervention. Food intake, body composition, resistance and, strength will also be evaluated. The effect size will be calculated using Cohen d and logistic regression models will be used to quantify the impact of the intervention by adjusting for different variables.

DISCUSSION

It expected that the intervention will improve the patients' quality of life, fatigue, pain and insomnia, as well as food and physical exercise habits, providing effectiveness evidence of a new therapy in addressing these syndromes in Primary Heath Care. Improvements in the quality of life will have a positive socioeconomic impact by reducing health expenditure on recurrent medical consultation, medication, complementary medical tests, etc and favor the maintenance of an active working life and productivity.

Psychological Outcomes and Quality of Life of Fibromyalgia Patients with Vitamin D Supplementation-A Meta-Analysis

The efficacy of current pharmaceutical treatments for fibromyalgia are limited. Vitamin D has shown promise in relieving pain. However, there is a lack of comprehensive analysis of psychological outcomes with vitamin D supplementation in fibromyalgia. This study aimed to investigate the impact of vitamin D supplementation on psychological outcomes and quality of life in fibromyalgia patients, given the unmet clinical need for effective treatment options. A meta-analysis of randomized controlled trials comparing vitamin D to placebo and prospective studies examining changes before and after vitamin D supplementation for patients with fibromyalgia was conducted to evaluate the effects of vitamin D on psychological outcomes, quality of life, and pain scores in patients with fibromyalgia. Databases were searched for relevant articles published from earliest available date to October 31, 2022. (PROSPERO number, CRD42022369889). We included 8 trials with a total of 694 participants and found that vitamin D supplementation had significant positive effects on physical function (standard mean differences (SMD) = 0.44, 95% CI = [0.10, 0.77 ]), role limitations due to emotional health (SMD = 0.57, 95% CI = [0.32, 0.82]), social function (SMD = 0.50, 95% CI = [0.08, 0.93]), and general health (SMD = 0.36, 95% CI = [0.11, 0.61]). Improvement of the Fibromyalgia Impact Questionnaire (FIQ) scores was noted (SMD = -0.414, 95% CI = [-0.808, -0.021]), but not on the Visual Analog Scale (VAS) (SMD = -0.15, 95% CI = [-0.771, 0.471]) and the Beck's Depression Inventory (BDI) scores (SMD = -0.456, 95% CI = [-1.27, 0.30]). In conclusion, vitamin D supplementation might be an alternative option for improvement of psychological outcomes and quality of life in patients with fibromyalgia.

Could the fibromyalgia syndrome be triggered or enhanced by COVID-19?

Fibromyalgia (FM) is a complex disease with an uncertain aetiology and intricate pathophysiology. Although its genesis is not fully explained, potential environmental factors, such as viral infections might trigger FM or worsen patients' clinical outcomes. The SARS-CoV-2 virus may affect central and peripheral nervous systems, leading to musculoskeletal, neurological, and psychological disturbances. These symptoms might persist at least 12 months beyond the recovery, often referred to as post-COVID syndrome, which resembles FM syndrome. In this sense, we argued the potential consequences of COVID-19 exclusively on FM syndrome. First, we have described post-COVID syndrome and its painful symptoms. Afterwards, we argued whether FM syndrome could be triggered or enhanced by COVID-19 infection or by numerous and persistent stressors imposed daily by the pandemic setting (isolation, uncertainty, depression, mental stress, generalized anxiety, and fear of the virus). In addition, we have demonstrated similarities between pathophysiological mechanisms and cardinal symptoms of FM and COVID-19, speculating that SARS-CoV-2 might represent a critical mediator of FM or an exacerbator of its symptoms once both syndromes share similar mechanisms and complaints. Therefore, pharmacologic and non-pharmacological approaches commonly used to treat FM could serve as strategic therapies to attenuate painful and neurological manifestations of post-COVID syndrome. Although it is still theoretical, clinicians and researchers should be alert of patients who develop symptoms similar to FM or those who had their FM symptoms increased post-COVID to manage them better.

The Importance of Nutrition as a Lifestyle Factor in Chronic Pain Management: A Narrative Review

In everyday clinical practice, healthcare professionals often meet chronic pain patients with a poor nutritional status. A poor nutritional status such as malnutrition, unhealthy dietary behaviors, and a suboptimal dietary intake can play a significant role in the occurrence, development, and prognosis of chronic pain. The relationship between nutrition and chronic pain is complex and may involve many underlying mechanisms such as oxidative stress, inflammation, and glucose metabolism. As such, pain management requires a comprehensive and interdisciplinary approach that includes nutrition. Nutrition is the top modifiable lifestyle factor for chronic non-communicable diseases including chronic pain. Optimizing one's dietary intake and behavior needs to be considered in pain management. Thus, this narrative review reports and summarizes the existing evidence regarding (1) the nutrition-related health of people experiencing pain (2) the underlying potential mechanisms that explain the interaction between nutrition and chronic pain, and (3) the role of nutrition screening, assessment and evaluation for people experiencing pain and the scope of nutrition practice in pain management. Future directions in the nutrition and chronic pain field are also discussed.

The Role of Tryptophan Dysmetabolism and Quinolinic Acid in Depressive and Neurodegenerative Diseases

Emerging evidence suggests that neuroinflammation is involved in both depression and neurodegenerative diseases. The kynurenine pathway, generating metabolites which may play a role in pathogenesis, is one of several competing pathways of tryptophan metabolism. The present article is a narrative review of tryptophan metabolism, neuroinflammation, depression, and neurodegeneration. A disturbed tryptophan metabolism with increased activity of the kynurenine pathway and production of quinolinic acid may result in deficiencies in tryptophan and derived neurotransmitters. Quinolinic acid is an N-methyl-D-aspartate receptor agonist, and raised levels in CSF, together with increased levels of inflammatory cytokines, have been reported in mood disorders. Increased quinolinic acid has also been observed in neurodegenerative diseases, including Parkinson’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis, and HIV-related cognitive decline. Oxidative stress in connection with increased indole-dioxygenase (IDO) activity and kynurenine formation may contribute to inflammatory responses and the production of cytokines. Increased formation of quinolinic acid may occur at the expense of kynurenic acid and neuroprotective picolinic acid. While awaiting ongoing research on potential pharmacological interventions on tryptophan metabolism, adequate protein intake with appropriate amounts of tryptophan and antioxidants may offer protection against oxidative stress and provide a balanced set of physiological receptor ligands.

The relationship between dietary total antioxidant capacity, clinical parameters, and oxidative stress in fibromyalgia syndrome: A novel point of view

Objectives

This study aims to reveal the relationship between serum total antioxidant status (TAS), clinical parameters, and nutrition (dietary total antioxidant capacity [TAC]) in patients with fibromyalgia.

Patients and methods

This cross-sectional study was conducted with a total of 60 female participants (mean age: 44.7±9.7 years; range, 18 to 50 years) at Gaziler Physical Medicine and Rehabilitation Hospital between July 2020 and February 2021. Thirty female patients with fibromyalgia were compared with 30 age-, sex-, and body mass index-matched healthy individuals. The short-form McGill Pain Questionnaire, Fibromyalgia Impact Questionnaire (FIQ), and Pittsburg Sleep Quality Index were used. Total antioxidant status, total oxidant status (TOS), and oxidative stress index (OSI) were measured. Dietary TAC was calculated using the ferric reducing ability of plasma according to a food frequency questionnaire.

Results

Total antioxidant status showed no significant difference between groups (p=0.080). Total oxidant status and OSI were significantly higher in the patient group (p<0.001 and p=0.005, respectively). The mean dietary TAC was 16.5±6.5 in the patient group and 17.2±6.2 in the control group, and it was similar between groups (p=0.492). Pittsburg Sleep Quality Index global score was significantly higher in the patient group than in the control group (p<0.001). Dietary TAC showed a moderate positive correlation with serum TAS in both groups (r=0.373, p=0.042 for the patient group, and r=0.380, p=0.038 for the control group). In the patient group, TOS and OSI showed a moderate positive correlation with FIQ total scores (r=0.420, p=0.021 and r=0.450, p=0.013, respectively). The mean polyunsaturated fatty acid and omega-6 intake of the patient group was significantly lower than the control group (p=0.025 for both). Dietary antioxidant intake from vegetables (p=0.025), legumes/nuts (p=0.049), and meat (p<0.001) was significantly lower, whereas dietary antioxidant intake from cereal and potatoes was significantly higher in the patient group compared to the control group (p=0.028).

Conclusion

The results indicate that oxidative stress can be reduced by increasing dietary antioxidant intake in fibromyalgia.

A Novel Formula Comprising Wolfberry, Figs, White Lentils, Raspberries, and Maca (WFWRM) Induced Antifatigue Effects in a Forced Exercise Mouse Model

Long-term body fatigue poses a threat to human health. To explore novel sources of antifatigue medicine and food, we developed a novel formula composed of wolfberry, figs, white lentils, raspberries, and maca (WFWRM) according to the theory of traditional Chinese medicine. In this study, we explored whether the administration of the WFWRM relieves fatigue. Thirty male Kunming mice were divided into three groups, which received either intragastric administration of saline, vitamin C (100 mg/kg), or WFWRM (1.00 g/kg) every day. After 30 days of treatment, all mice exhaustively performed weight-bearing swimming. Another ten mice that did not perform swimming were treated with saline for 30 days and used as sedentary control. The antifatigue effect and biochemical oxidation phenomena were assessed in the exercise-exhausted model and sedentary controls. The histopathological changes in the liver and kidney tissues of mice were observed by performing hematoxylin-eosin (HE) staining. After 30 days of oral administration, the liver and kidney tissues of mice were healthy and show no pathological changes. Compared to the fatigue model group, WFWRM significantly increased the rota-rod time of the mice. Also, the concentrations of lactic acid (LA), blood urea nitrogen (BUN), creatine kinase (CK), and lactate dehydrogenase (LDH) in the WFWRM group significantly reduced. On the contrary, the levels of hepatic glycogen (LG), muscle glycogen (MG), and serum glucose (GLU) increased in the WFWRM group. Besides, WFWRM markedly reduced the levels of malondialdehyde (MDA) but increased the levels of glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD). Pearson correlation analysis indicated that the concentrations of the sources of energy (LG, MG, and GLU) significantly correlated with those of metabolites (BLA, BUN, CK, and LDH) and antioxidant levels (SOD, GSH-PX, and MDA). Overall, our results suggested that the supplementation of WFWRM could improve exercise capacity and relieve fatigue probably by normalizing energy metabolism and attenuating oxidation.

Therapeutic Approaches to Nociplastic Pain Based on Findings in the Reserpine-Induced Fibromyalgia-Like Animal Model

Nociplastic pain, the third category of chronic pain, has emerged as a serious medical issue. Due to its significant negative influences on patients and society, high prevalence, and lack of sufficiently effective treatments, more efficacious therapies are required. This review highlights the potential therapeutic approaches identified in studies that used reserpine-induced myalgia (RIM) animal model that exhibits nociplastic pain-associated phenotypes. These studies have revealed that biological processes including the chronic reduction of monoamines, increase of oxidative/nitrosative stresses and inflammatory mediators, upregulation of pronociceptive neurotransmitters and their receptors, increase of trophic factors, enhancement of the apoptotic pathway, sensory nerve sensitization, and activation of immune cells in central and/or peripheral regions, underly the nociplastic pain-associated phenotypes in RIM animal model. Potential therapeutic approaches to nociplastic pain, i.e., 1) functional modification of specific molecules which expression is distinctly altered following monoamine reduction, 2) targeting the molecules which are responsible for other major categories of chronic pain (i.e., chronic inflammatory pain and neuropathic pain), 3) supplementation of nutrition to correct the disrupted nutritional balance, 4) improvement of physical constitution by natural substances, and 5) nonpharmacological interventions, have been identified. Significance Statement Studies in RIM animal model have revealed the pathologies that occur after the chronic reduction of monoamines and identified potential therapeutic approaches to nociplastic pain. Translation of their analgesic efficacy from RIM animal model to patients remains an issue to be addressed. Successful translation would lead to better therapies for nociplastic pain.

Dysfunctional eating behavior in fibromyalgia and its association with serum biomarkers of brain plasticity (BDNF and S100B): an exploratory study

OBJECTIVE

To assess disordered eating, hunger and satiety perceptions in women with fibromyalgia (FM) compared to healthy controls (HC) and their association with biomarkers of brain plasticity (brain-derived neurotrophic factor (BDNF) and S100 calcium-binding protein B (S100B)).

METHODS

Cross-sectional exploratory study. The sample included FM (n = 20) and HC (n = 19), matched to age and waist perimeter. Dysfunctional eating was assessed through the Three Factor Eating Questionnaire and Eating Disorders Examination with a questionnaire. Hunger and satiety levels were rated by a Numerical Scale. Serum leptin, S100B and BDNF were analyzed.

RESULTS

The MANCOVA analysis showed that the mean of Emotional Eating rates was 30.65% higher in FM compared to HC (p = 0.015). Eating, shape and weight concerns were 77.77%, 57.14% and 52.22% higher in FM (p = <0.001) compared to HC, respectively. Moreover, the FM group reported higher scores for feeling of hunger "[5.2 (±2.9) vs. 4.8 (±2.0); p = 0.042] and lower scores for satiety [7.0 (±1.7) vs. 8.3 (±1.0); p = 0.038]. In the FM group, serum BDNF was negatively associated with hunger (r = - 0.52; p = 0.02), while S100B was positively associated with hunger scores (r = 0.463; p = 0.004).

CONCLUSION

The present findings support the hypothesis that the association between FM and obesity can be mediated by a hedonistic pathway. Further research is needed.

Magnesium and Fibromyalgia: A Literature Review

Fibromyalgia, a widespread chronic pain disorder, imposes a multitude of hardships on patients and their communities. Supplements, specifically magnesium supplements, have been widely used by fibromyalgia patients in an attempt to control their symptoms. The aim of this work is to investigate if the widespread use of magnesium in fibromyalgia is supported by evidence in the literature. This review provides a layout of the studies examining the correlation between body magnesium levels and fibromyalgia. Furthermore, it elaborates on the trials testing the effectiveness of magnesium in treating different clinical parameters of fibromyalgia.

Animal models of fibromyalgia: What is the best choice?

Fibromyalgia (FM) is a complex syndrome, with an indefinite aetiology and intricate pathophysiology that affects 2 - 3% of the world population. From the beginning of the 2000s, experimental animal models have been developed to mimic clinical FM and help obtain a better understanding of the relevant neurobiology. These animal models have enabled a broad study of FM symptoms and mechanisms, as well as new treatment strategies. Current experimental FM models include the reserpine-induced systemic depletion of biogenic amines, muscle application of acid saline, and stress-based (cold, sound, or swim) approaches, among other emerging models. FM models should: (i) mimic the cardinal symptoms and complaints reported by FM patients (e.g., spontaneous nociception, muscle pain, hypersensitivity); (ii) mimic primary comorbidities that can aggravate quality of life and lead to worse outcomes (e.g., fatigue, sleep disturbance, depression, anxiety); (iii) mimic the prevalent pathological mechanisms (e.g., peripheral and central sensitization, inflammation/neuroinflammation, change in the levels of the excitatory and inhibitory neurotransmitters); and (iv) demonstrate a pharmacological profile similar to the clinical treatment of FM. However, it is difficult for any one of these models to include the entire spectrum of clinical FM features once even FM patients are highly heterogeneous. In the past six years (2015 - 2020), a wide range of experimental FM studies has amounted to the literature reinforcing the need for an updated review. Here we have described, in detail, several approaches used to experimentally study FM, with a focus on recent studies in the field and in previously less discussed mechanisms. We highlight each model's challenges, limitations, and future directions, intending to help preclinical researchers establish the correct experimental FM model to use depending on their goals.

Vegetarian and Vegan Diet in Fibromyalgia: A Systematic Review

Fibromyalgia (FM) is a chronic non-degenerative disease characterized by the presence of multiple symptoms such as chronic pain, which negatively influence the quality of life of sufferers, most of whom are women. Currently, there is no effective treatment to limit the impact of these symptoms. The aim of this research is to review the scientific evidence on the effect of following a vegetarian or vegan diet on fibromyalgia patients. A systematic review included the original articles that answered the research question. These articles were in 2021 in the PubMed, Web of Science and Scopus databases. The research used the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines. No time restriction was applied, and grey literature was not included. The evaluation of the methodological quality of the articles was carried out using the following different scales: STROBE (strengthening the reporting of observational studies in epidemiology), PEDro (Physiotherapy Evidence Database), and MMAT (Mixed Methods Appraisal Tool) scales. A total of 88 studies were analyzed, of which 6 investigations were included in this systematic review (n = 4 clinical trials and n = 2 cohort studies). These investigations show significant improvements in biochemical parameters, quality of life, quality of sleep, pain at rest and general health status when following mainly plant-based dietary patterns. In conclusion, these findings are promising but interpretation of the findings is limited due to the methodological quality of the studies. Well-designed clinical trials are needed to consolidate these dietary recommendations in FM patients.

[Role of B vitamins, thiamine, pyridoxine, and cyanocobalamin in back pain and other musculoskeletal conditions: a narrative review]

Low back pain, as well as other musculoskeletal disorders (neck pain, osteoarthritis, etc.), are a very frequent cause of consultation both in primary care and in other hospital specialties and are usually associated with high functional and work disability. Acute low back pain can present different nociceptive, neuropathic and nonciplastic components, which leads to consider it as a mixed type pain. The importance of the concept of mixed pain is due to the fact that the symptomatic relief of these pathologies requires a multimodal therapeutic approach to various pharmacological targets. The antinociceptive role of the B vitamin complex has been recognized for several decades, specifically the combination of Thiamine, Pyridoxine and Cyanocobalamin (TPC). Likewise, there is accumulated evidence that indicates an adjuvant analgesic action in low back pain. The aim of the present review is to present the existing evidence and the latest findings on the therapeutic effects of the TPC combination in low back pain. Likewise, some of the most relevant mechanisms of action involved that can explain these effects are analyzed. The reviewed evidence indicates that the combined use of PCT has an adjuvant analgesic effect in mixed pain, specifically in low back pain and other musculoskeletal disorders with nociceptive and neuropathic components. This effect can be explained by an anti-inflammatory, antinociceptive, neuroprotective and neuromodulatory action of the TPC combination on the descending pain system.

Pain in Women: A Perspective Review on a Relevant Clinical Issue that Deserves Prioritization

Introduction

Gender equity and gender medicine are opportunities not to be missed, and this Expert Group Opinion Paper on pain in women aims to review the treatment of pain conditions mainly affecting women, as well as the fundamental aspects of the different clinical response to drug treatment between the genders, and what can be done for gender-specific rehabilitation.

Methods

Perspective review.

Results

Genotypic and phenotypic differences in pain between the sexes are conditioned by anatomical, physiological, neural, hormonal, psychological, social, and cultural factors, such as the response to pharmacological treatment to control pain. The examination of these factors shows that women are affected by pain diseases more frequently and severely than men and that they report pain more frequently and with a lower pain threshold than men. Some forms of pain are inherently related to gender differences, such as pain related to the genitourinary system. However, other forms of chronic pain are seen more frequently in women than men, such as migraine, rheumatological, and musculoskeletal pain, in particular fibromyalgia.

Discussion

Research is needed into the pathophysiological basis for gender differences in the generation of acute pain and maintenance of chronic pain, including the factors that put women at higher risk for developing chronic pain. In addition, different specialties need to collaborate to develop gender-related diagnostic and therapeutic guidelines, and healthcare professionals need to upskill themselves in the appropriate management of pain using existing diagnostic tools and therapeutic options.

Targeted Treatment of Age-Related Fibromyalgia with Supplemental Coenzyme Q10

Fibromyalgia is a common chronic pain condition of unknown aetiology, although mitochondrial dysfunction, oxidative stress, and inflammation have been implicated in the pathophysiology of this disorder. Treatment generally involves physiotherapy, anticonvulsants, and antidepressant therapy; however, the symptomatic relief conferred by these treatments can be very variable, and there is a need for additional therapeutic strategies. One such treatment which is gaining a lot of interest is the use of coenzyme Q10 (CoQ10) supplementation. The therapeutic efficacy associated with CoQ10 supplementation is thought to arise from the ability of supplementation to restore an underlying deficit in CoQ10 status which has been associated with fibromyalgia together with the ability of CoQ10 to improve mitochondrial activity, restore cellular antioxidant capacity, and ameliorate inflammation. This chapter outlines the evidence supporting the therapeutic utility of CoQ10 in the treatment of fibromyalgia.

Food Implications in Central Sensitization Syndromes

Fibromyalgia (FM), chronic fatigue syndrome (CFS) and multiple chemical sensitivity (MCS) are some of the central sensitization syndromes (CSSs). The complexity of their diagnosis, the high interindividual heterogeneity and the existence of multi-syndromic patients requires a multifaceted treatment. The scientific literature is contradictory regarding the role of food in CSS, and evidence on the role of nutrition in MCS is particularly scarce. This review consists in gathering information about the current status of dietary recommendations (i.e., special dietary interventions, the role of additives, presence of micronutrient deficiencies, nutritional supplements and elimination of other nutrients and substances) and discussing the scientific evidence in depth to shed light on appropriate nutritional treatment managements for CSS patients. Current indications show that dietary modifications may vastly improve the patients’ quality of life at a low cost. We suggest personalized treatment, taking into consideration the severity of the disease symptoms, quality of life, coexistence with other diseases, pharmacological treatment, changing clinical characteristics, nutritional status, energy requirements and food tolerances, among others, as the best ways to tailor specific dietary interventions. These approaches will partially overcome the lack of scientific and clinical research on MSC. Patients should also be advised on the serious consequences of following dietary guidelines without a dietitian’s and clinician’s supervision.

Effectiveness of a Khorasan Wheat-Based Replacement on Pain Symptoms and Quality of Life in Patients with Fibromyalgia

OBJECTIVE

To investigate the effects of a replacement diet with Khorasan wheat products in patients with fibromyalgia, in comparison with a similar replacement diet with control products made from organic semi-whole-grain modern wheat.

DESIGN

Randomized, double-blinded crossover trial.

SETTING

Outpatient clinic.

SUBJECTS

Twenty subjects (19 female and one male, mean age = 48.9 ± 12.3 years) with fibromyalgia.

METHODS

Participants were randomly assigned to consume either Khorasan or control wheat products (pasta, bread, crackers, biscuits) for eight weeks and then crossed. Validated self-administered questionnaires were collected from each subject at the beginning and end of each intervention period.

RESULTS

A general linear model for repeated measurement, adjusted for potential confounders, showed that the overall score reported from each questionnaire improved after both intervention and control periods, but the effect was more evident after the intervention with Khorasan. In particular, a statistically significant difference in Widespread Pain Index (WPI) + Severity Scale (SS) and Functional Outcome of Sleep Questionnaire (FOSQ) was observed, which decreased significantly by 21.5% and 11.7% respectively, only after the Khorasan period, while no statistically significant variations were reported after the control period. Similarly, FM Impact Questionnaire scores decreased significantly only after the Khorasan period, with a reduction that was significantly different between the intervention and control periods (-22.5% vs -0.3%, P = 0.037). The improvement was even greater in people with higher symptom severity.

CONCLUSIONS

A dietary intervention with Khorasan wheat products seems to benefit patients with fibromyalgia, especially those with greater symptom severity.

Nutritional Interventions in the Management of Fibromyalgia Syndrome

Fibromyalgia (FM) is a multifactorial syndrome of unknown etiology, characterized by widespread chronic pain and various somatic and psychological manifestations. The management of FM requires a multidisciplinary approach combining both pharmacological and nonpharmacological strategies. Among nonpharmacological strategies, growing evidence suggests a potential beneficial role for nutrition. This review summarizes the possible relationship between FM and nutrition, exploring the available evidence on the effect of dietary supplements and dietary interventions in these patients. Analysis of the literature has shown that the role of dietary supplements remains controversial, although clinical trials with vitamin D, magnesium, iron and probiotics' supplementation show promising results. With regard to dietary interventions, the administration of olive oil, the replacement diet with ancient grains, low-calorie diets, the low FODMAPs diet, the gluten-free diet, the monosodium glutamate and aspartame-free diet, vegetarian diets as well as the Mediterranean diet all appear to be effective in reducing the FM symptoms. These results may suggest that weight loss, together with the psychosomatic component of the disease, should be taken into account. Therefore, although dietary aspects appear to be a promising complementary approach to the treatment of FM, further research is needed to provide the most effective strategies for the management of FM.

Dietary Patterns and Interventions to Alleviate Chronic Pain

Pain is one of the main problems for modern society and medicine, being the most common symptom described by almost all patients. When pain becomes chronic, the life of the patients is dramatically affected, being associated with significant emotional distress and/or functional disability. A complex biopsychosocial evaluation is necessary to better understand chronic pain, where good results can be obtained through interconnected biological, psychological, and social factors. The aim of this study was to find the most relevant articles existent in the PubMed database, one of the most comprehensive databases for medical literature, comprising dietary patterns to alleviate chronic pain. Through a combined search using the keywords "chronic pain" and "diet" limited to the last 10 years we obtained 272 results containing the types of diets used for chronic pain published in the PubMed database. Besides classical and alternative methods of treatment described in literature, it was observed that different diets are also a valid solution, due to many components with antioxidant and anti-inflammatory qualities capable to influence chronic pain and to improve the quality of life. Thirty-eight clinical studies and randomized controlled trials are analyzed, in an attempt to characterize present-day dietary patterns and interventions to alleviate chronic pain.

Hydroxytyrosol as a Promising Ally in the Treatment of Fibromyalgia

Fibromyalgia (FM) is a chronic and highly disabling syndrome, which is still underdiagnosed, with controversial treatment. Although its aetiology is unknown, a number of studies have pointed to the involvement of altered mitochondrial metabolism, increased oxidative stress and inflammation. The intake of extra virgin olive oil, and particularly of one of its phenolic compounds, hydroxytyrosol (HT), has proven to be protective in terms of redox homeostatic balance and the reduction of inflammation. In this context, using a proteomic approach with nanoscale liquid chromatography coupled to tandem mass spectrometry, the present study analysed: (i) Changes in the proteome of dermal fibroblasts from a patient with FM versus a healthy control, and (ii) the effect of the treatment with a nutritional relevant dose of HT. Our results unveiled that fibroblast from FM show a differential expression in proteins involved in the turnover of extracellular matrix and oxidative metabolism that could explain the inflammatory status of these patients. Moreover, a number of these proteins results normalized by the treatment with HT. In conclusion, our results support that an HT-enriched diet could be highly beneficial in the management of FM.

Psychological and Sleep Effects of Tryptophan and Magnesium-Enriched Mediterranean Diet in Women with Fibromyalgia

Anxiety, mood disturbance, eating and sleep disorders, and dissatisfaction with body image are prevalent disorders in women with fibromyalgia. The authors of this study aimed to determine the effects of tryptophan (TRY) and magnesium-enriched (MG) Mediterranean diet on psychological variables (trait anxiety, mood state, eating disorders, self-image perception) and sleep quality in women with fibromyalgia (n = 22; 49 ± 5 years old). In this randomized, controlled trial, the participants were randomly assigned to the experimental group and the placebo group. The intervention group received a Mediterranean diet enriched with high doses of TRY and MG (60 mg of TRY and 60 mg of MG), whereas the control group received the standard Mediterranean diet. Pittsburgh Sleep Quality Questionnaire, Body Shape Questionnaire, State-Trait Anxiety Inventory (STAI), Profile of Mood States (POMS-29) Questionnaire, Eating Attitudes Test-26, and Trait Anxiety Inventory were completed before and 16 weeks after the intervention. Significant differences were observed between groups after the intervention for the mean scores of trait anxiety (p = 0.001), self-image perception (p = 0.029), mood disturbance (p = 0.001), and eating disorders (p = 0.006). This study concludes that tryptophan and magnesium-enriched Mediterranean diet reduced anxiety symptoms, mood disturbance, eating disorders, and dissatisfaction with body image but did not improve sleep quality in women with fibromyalgia.

Comparison between Acupuncture and Nutraceutical Treatment with Migratens® in Patients with Fibromyalgia Syndrome: A Prospective Randomized Clinical Trial

OBJECTIVES

Fibromyalgia syndrome (FMS) is a chronic clinical condition characterized by pain, fatigue, altered sleep, and cognitive disturbances. The purpose of this study was to compare two alternative treatments (nutraceutical and acupuncture) in FMS patients through a randomized clinical trial.

RESEARCH METHODS

A total of 60 FMS female patients were randomized for treatment with a nutritional combination containing coenzyme Q10, vitamin D, alpha-lipoic acid, magnesium, and tryptophan (Migratens® Group) or acupuncture treatment (Acupuncture Group) performed according the principles of traditional Chinese medicine (TCM), both for 3 months. Changes in pain and in quality of life (QoL) measured with a Fibromyalgia Impact Questionnaire Score-Revised (FIQ-R) and the Fibromyalgia Severity Scale (FSS) were performed at 1, 3, and 6 months after the start of treatments.

RESULTS

A total of 55 patient completed the study (21 in the Migratens® Group and 34 in the Acupuncture Group). Migratens® treatment shows a statistically significant reduction of pain 1 month after the start of therapy (T1, p = 0.025), strengthened after 3 months with maintenance of treatment (p = 0.012). The efficacy in reducing pain was apparent in the Acupuncture Group at all post-treatment determinations and at follow-up (T1 and T2 p = <0.001). Regarding QoL, improvement in FIQ-R and FSS values was revealed in both groups.

CONCLUSION

The nutraceutical approach with Migratens® seems to be an effective option to for patients with FMS. Our experience confirmed also the validity of acupuncture in these patients. Considering the complexity of the management of FMS patients, our results suggest a cyclical and sequential, or even concurrent treatment with different approaches, to improve the efficacy and the compliance of patients to long-term treatment.

Relations between serum magnesium and calcium levels and body composition and metabolic parameters in women with fibromyalgia

OBJECTIVE

Correlate serum magnesium (Mg) and Calcium (Ca) levels with body composition and metabolic parameters in women with fibromyalgia (FM).

PATIENTS AND METHODS

Cross-sectional study compared with a control group paired by age and body mass index (BMI) of adult women diagnosed with fibromyalgia. All participants went through assessment of their body composition through dual-energy X-ray absorptiometry (DXA) and had blood samples collected for dosing of Mg, Ca, C-reactive Protein (CRP), lipidogram and glycemia.

RESULTS

53 women with FM (average age 48.1 ± 8.2 years, average BMI 26.6 ± 4.5 kg/m²) and 50 control women (average age 47.1 ± 9.9 years, average BMI 25.6 ± 3.6 kg/m²) participated in the study. Serum levels turned out to have inverse correlation with CRP in the FM group (r = - 0.29, p = 0.03) and with BMI and glycemia in the control group (r = 0.31; p = 0.02 and r = 0.48; p = 0.0004 respectively). Serum levels of calcium correlated with triglycerides (r = 0.29; p = 0.03) in the FM group and with glycemia in the control group (r = 0.64; p = 0.0001).

CONCLUSIONS

In patients with FM, magnesemia turned out to have inverse correlation with CRP and calcemia had positive association with triglycerides.

Do Nutritional Factors Interact with Chronic Musculoskeletal Pain? A Systematic Review

Dietary patterns may play an important role in musculoskeletal well-being. However, the link between dietary patterns, the components of patients’ diet, and chronic musculoskeletal pain remains unclear. Therefore, the purpose of this review was to systematically review the literature on the link between dietary patterns, the components of patients’ diet and chronic musculoskeletal pain. This review was conducted following the “Preferred Reporting Items for Systematic reviews and Meta-Analyses” (PRISMA) guidelines and was registered in PROSPERO with the registration number CRD42018110782. PubMed, Web of Science, and Embase online databases were searched. After screening titles and abstracts of 20,316 articles and full texts of 347 articles, 12 eligible articles were included in this review, consisting of nine experimental and three observational studies. Seven out of nine experimental studies reported a pain-relieving effect of dietary changes. Additionally, protein, fat, and sugar intake were found to be associated with pain intensity and pain threshold. In conclusion, plant-based diets might have pain relieving effects on chronic musculoskeletal pain. Patients with chronic rheumatoid arthritis pain can show inadequate intake of calcium, folate, zinc, magnesium, and vitamin B6, whilst patients with fibromyalgia can show a lower intake of carbohydrates, proteins, lipids, vitamin A-E-K, folate, selenium, and zinc. Chronic pain severity also shows a positive relation with fat and sugar intake in osteoarthritis, and pain threshold shows a positive association with protein intake in fibromyalgia.

Mercury-induced autoimmunity: Drifting from micro to macro concerns on autoimmune disorders

Mercury (Hg) is widely recognized as a neurotoxic metal, besides it can also act as a proinflammatory agent and immunostimulant, depending on individual exposure and susceptibility. Mercury exposure may arise from internal body pathways, such as via dental amalgams, preservatives in drugs and vaccines, and seafood consumption, or even from external pathways, i.e., occupational exposure, environmental pollution, and handling of metallic items and cosmetics containing Hg. In susceptible individuals, chronic low Hg exposure may trigger local and systemic inflammation, even exacerbating the already existing autoimmune response in patients with autoimmunity. Mercury exposure can trigger dysfunction of the autoimmune responses and aggravate immunotoxic effects associated with elevated serum autoantibodies titers. The purpose of the present review is to provide a critical overview of the many issues associated with Hg exposure and autoimmunity. In addition, the paper focuses on individual susceptibility and other health effects of Hg.

Attenuation of reserpine-induced fibromyalgia via ROS and serotonergic pathway modulation by fisetin, a plant flavonoid polyphenol

Fibromyalgia (FM) is a chronic complex musculoskeletal disorder characterized by widespread musculoskeletal pain accompanied by fatigue, sleep disturbance, memory defects and mood changes. Fisetin, a plant flavonoid polyphenol, has been reported to possess potent antioxidant, antinociceptive and neuroprotective activities. The present study aimed to evaluate the efficacy of fisetin against reserpine-induced FM (RIF) in rats. RIF was induced in male Wistar rats (180–220 gm) using reserpine (1 mg/kg; subcutaneous; once daily for 3 consecutive days) and the rats were treated with fisetin (5, 10 and 25 mg/kg) for 21 days. Various behavioral, biochemical and molecular parameters were evaluated. Administration of reserpine induced allodynia, hyperalgesia and depression, which were significantly ameliorated (P<0.05) by fisetin (10 and 25 mg/kg), as reflected by an increase in paw and tail withdrawal latency, increased paw withdrawal threshold, and decreased immobility time. Reserpine led to decreased biogenic amine levels [5-hydroxytryptamine (5-HT), noradrenaline (NA) and dopamine (DA)] and increased the ratio to their metabolite 3,4-dihydroxyphenylacetic acid. 5-hydroxyindoleacetic acid in the spinal cord, thalamus and prefrontal cortex was significantly decreased (P<0.05) by fisetin. Immunohistological analysis of brain tissue revealed that fisetin significantly inhibited (P<0.05) reserpine-induced depletion of 5-HT. It also significantly inhibited (P<0.05) elevated oxido-nitrosative stress and reactive oxygen species (ROS) levels, as analyzed by flow cytometry in RIF rats. Fisetin exerts its antinociceptive and anti-depressive potential via modulation of decreased levels of biogenic amines (5-HT, NA and DA), elevated oxido-nitrosative stress and ROS to ameliorate allodynia, hyperalgesia, and depression in experimental RIF.

Relation between magnesium and calcium and parameters of pain, quality of life and depression in women with fibromyalgia

OBJECTIVE

Determine food intake and levels of serum magnesium (Mg) and calcium (Ca) and correlate these minerals with pain, quality of life and depression risk in women with and without fibromyalgia (FM).

PATIENTS AND METHODS

Fifty-three women diagnosed with FM and 50 healthy women participated in the study, where all of them had equivalent age and body mass index (BMI). All women underwent anthropometric assessment, physical exams of pain perception threshold and tender point (TP) count, blood sample collection, and filling out of FM impact questionnaire (FIQ), Patient Health Questionnaire-9 (PHQ-9), and 3-day dietary record (DR).

RESULTS

Dietary intake of Mg and Ca was substantially lower by women with FM. There were no differences in levels of serum Mg and Ca in the groups under analysis. For the FM group, dietary intake of Mg and Ca had inverse correlation with TP and direct relation with the pain threshold.

CONCLUSIONS

Although women with FM had lower dietary intake of Mg and Ca, serum levels for these nutrients were not different between the groups. Low dietary intake of minerals correlated with worsened pain threshold parameters.

Mediterranean Diet, Body Composition, and Activity Associated With Bone Health in Women With Fibromyalgia Syndrome

BACKGROUND

There is very little scientific literature on the potential relationships between modifiable factors, including body composition, dietary pattern and physical activity (PA), and bone status in patients with fibromyalgia-a musculoskeletal condition characterized by chronic, widespread pain that is often accompanied by a broad spectrum of symptoms.

OBJECTIVES

The aim of the study was to investigate the impact of body composition parameters, adherence to the Mediterranean diet (Med Diet), and PA on bone health in a population of premenopausal and postmenopausal women with fibromyalgia syndrome (FMS).

METHODS

Ninety-five women diagnosed with FMS were included in this cross-sectional study. Body composition, including fat mass, percentage of fat mass, and lean mass (LM), were calculated using a body composition analyzer. Adherence to the Med Diet was measured through a validated 14-item questionnaire. The International Physical Activity Questionnaire was used to assess PA. Bone mass at the calcaneus was estimated through quantitative ultrasound.

RESULTS

Linear regression analysis revealed that LM had a significant association with broadband ultrasound attenuation (β = 0.211, 95% CI [0.046, 1.259], p = .035) and stiffness index parameters (β = 0.201, 95% CI [0.019, 1.654], p = .045) after adjusting for age and menopausal status. The Med Diet was also significantly associated with broadband ultrasound attenuation (β = 1.693, 95% CI [0.508, 2.879], p = .006).

DISCUSSION

LM and the Med Diet were consistently associated with calcaneal quantitative ultrasound parameters, supporting the hypothesis that LM and adherence to the Med Diet play determinant roles in bone health in FMS women. Training programs to maximize LM and strategies for promoting good adherence to the Med Diet should be considered in order to prevent the development of osteoporosis in FMS women. Because nurses are involved in implementing preventive programs, their roles in promoting this adherence to the Med Diet and maximizing LM in patients with FMS should help reduce the impact of osteoporosis.

Mitochondrial Dysfunction in Skeletal Muscle of a Fibromyalgia Model: The Potential Benefits of Melatonin

Fibromyalgia syndrome (FMS) is considered a musculoskeletal disorder associated to other symptoms including chronic pain. Since the hypothesis of FMS etiogenesis is consistent with mitochondrial dysfunction and oxidative stress, we evaluated the pathophysiological correlation among these factors studying some proteins involved in the mitochondrial homeostasis. We focused our attention on the roles of peroxisome proliferator activated receptor gamma coactivator-1alpha (PGC-1α), mitofusin2 (Mfn2), and coenzyme Q10 (CoQ10) in reserpine-induced myalgic (RIM) rats that manifest fibromyalgia-like chronic pain symptoms. First, we underlined that RIM rats are a good model for studying the pathophysiology of FMS and moreover, we found that PGC-1α, Mfn2, and CoQ10 are involved in FMS. In fact, their expressions were reduced in gastrocnemius muscle determining an incorrect mitochondrial homeostasis. Today, none of the currently available drugs are fully effective against the symptoms of this disease and they, often, induce several adverse events; hence, many scientists have taken on the challenge of searching for non-pharmacological treatments. Another goal of this study was therefore the evaluation of the potential benefits of melatonin, an endogenous indoleamine having several functions including its potent capacity to induce antioxidant enzymes and to determine the protective or reparative mechanisms in the cells. We observed that melatonin supplementation significantly preserved all the studied parameters, counteracting oxidative stress in RIM rats and confirming that this indoleamine should be taken in consideration for improving health and/or counteract mitochondrial related diseases.