Myasthenia Gravis: A Nutrition and Natural-Health Reference
1. Definition and Overview
Myasthenia gravis (MG) is a relatively rare autoimmune disorder in which antibodies form against nicotinic acetylcholine (ACh) postsynaptic receptors at the neuromuscular junction (NMJ) of the skeletal muscles, causing muscle weakness and rapid muscle fatigue. It is an autoimmune disease, which means that the body's defense system mistakenly attacks healthy cells or proteins needed for normal functioning.
MG is an autoimmune neurological disorder characterized by defective transmission at the neuromuscular junction. The incidence of the disease is 4.1 to 30 cases per million person-years, and the prevalence rate ranges from 150 to 200 cases per million. The published prevalence has steadily increased, and one can estimate that there are approximately 60,000 patients with MG in the United States. Current trends indicate that, as the population ages, an increasing number of patients with MG can be expected, but the clinical patterns of the disease may change.
Myasthenia gravis has a prevalence of 20 per 100,000 population in the US. It exhibits a female predominance in those less than 40 years of age and a male predominance in those greater than 50 years of age. Childhood MG is quite uncommon in western populations but is prevalent in Asian countries, with involvement of around 50% of patients aged less than 15 years.
2. The Neuromuscular Junction and Body Systems Involved
2.1 The Neuromuscular Junction
The basic pathology is a reduction in the number of ACh receptors (AChRs) at the postsynaptic muscle membrane brought about by an acquired autoimmune reaction producing anti-AChR antibodies. The reduction in the number of AChRs results in a characteristic pattern of progressively reduced muscle strength with repeated use and recovery of muscle strength after a period of rest.
Less commonly identified autoantibodies include those targeted to muscle-specific kinase (MuSK), low-density lipoprotein receptor-related protein 4 (Lrp4), and agrin. These autoantibodies disrupt cholinergic transmission between nerve terminals and muscle fibers by causing downregulation, destruction, functional blocking of AChRs, or disrupting the clustering of AChRs in the postsynaptic membrane.
In most MG patients (~85%), the autoimmune attack is against the nicotinic acetylcholine receptor (AChR), which is located at the post-synaptic endplate; additional autoantigens are the muscle-specific tyrosine kinase (MuSK, 5–8% of patients) and the lipoprotein-related protein 4 (LRP4, 1–33% of patients), which are two proteins that are involved in AChR clustering at the NMJ.
The distinctive features in MG, particularly the fluctuating nature of a patient's strength, is attributed to the unique pathophysiology of impaired neuromuscular transmission. This pathophysiology produces a dynamic rather than a fixed disorder as a result of the relative ease by which NMJs repair.
2.2 Muscle and Voluntary Movement Systems
Myasthenia gravis is a chronic neuromuscular disease that causes weakness in the voluntary muscles. Voluntary muscles include muscles that connect to a person's bones, muscles in the face, throat, and diaphragm. They contract to move the arms and legs and are essential for breathing, swallowing, and facial movements.
The core clinical manifestation of MG is fatigable muscle weakness, which may affect ocular, bulbar, respiratory, and limb muscles. The majority of patients with MG first present with ocular symptoms. Most patients with MG will experience at least one exacerbation of symptoms throughout the course of their illness.
2.3 The Immune System
MG is clearly an autoimmune disease in which the specific antibody has been characterized completely. In as many as 90% of generalized cases, IgG to AChR is present. In n-AChR MG, the antibodies are of the IgG1 and IgG3 subtype. They bind to the n-ACh receptor present in the postsynaptic membrane of the skeletal muscles and activate the complement system leading to the formation of the membrane attack complex (MAC).
2.4 The Thymus
The thymus has been recognized as the prime site of autosensitization in AChR-MG patients, who mostly (~80%) present thymic abnormalities, including follicular hyperplasia and thymoma. Its role as an immunological niche for autoimmunity development and perpetuation in MG patients is supported by the beneficial effects of thymectomy in patients with a hyperplastic thymus, as demonstrated by the MGTX trial and its 2-year extension study. Thymic hyperplasia is present in about 60% of AChR-MG patients, who are mostly female with early-onset (<50 years) disease.
Patients with thymomas often develop autoimmune neuromuscular diseases, including myasthenia gravis. Autoantigen expression in thymomas plays an important role in disease pathogenesis. Since thymomas are mainly composed of the cortex, with few medullae, MG may be caused by immature thymoma-derived T cells that fail to undergo negative selection and have not yet acquired sufficient self-tolerance.
Myasthenia gravis is an autoimmune disease mediated, in approximately 80% of patients, by antibodies against the nicotinic acetylcholine receptor (AChR+). Epithelial tumours (thymomas) are present in about 10–20% of patients.
2.5 Respiratory System
Myasthenia gravis causes a significant number of complications. These include myasthenic crisis, an acute respiratory paralysis that requires intensive care, as well as adverse events due to long-term medication treatment like opportunistic infections and lymphoproliferative malignancies.
3. Contributing and Associated Factors
3.1 Genetic Susceptibility and Immunological Mechanisms
Myasthenia gravis, similar to other autoimmune disorders, occurs in genetically susceptible individuals. Precipitating factors include conditions like infections, immunization, surgeries, and drugs.
Several factors have been implicated in thymoma-associated MG pathogenesis, including ectopic expression of autoantigens in thymomas, immature T cell production, Treg decrease, and impaired negative selection due to AIRE deficiency, reduced HLA expression, and CTLA-4 overexpression.
3.2 Viral and Infectious Triggers
Using sensitive molecular and immunohistochemical techniques, researchers have identified an active EBV (Epstein-Barr virus) infection in the MG thymus. A pathogenic model of virus-mediated autoimmunity in MG has been proposed. EBV infection may contribute to MG-specific autoimmune responses occurring within a chronically inflamed MG thymus, through its ability to promote activation, survival, and expansion of autoreactive B cells. The overall results strongly suggest that inflammation and EBV infection are key events in the intrathymic pathogenesis of MG.
3.3 Gut Microbiota Dysbiosis
The human gut microbiota is vital for maintaining human health in terms of immune system homeostasis. Perturbations in the composition and function of microbiota have been associated with several autoimmune disorders, including myasthenia gravis.
Mendelian randomization research has revealed causal relationships between cytokines, gut microbiotas, and serum metabolites and the risk of myasthenia gravis. The literature suggests the involvement of circulating cytokines (CK), gut microbiota (GM), and serum metabolites (SM) with MG.
A total of 20 risk factors for MG and its subtypes were identified using Mendelian randomization methods. The factors included 9 serum metabolites, 6 gut microbiota, and 2 circulating cytokines. Additional analysis of 2 MG subtypes — early-onset MG (EOMG) and late-onset MG (LOMG) — found that cytokines and serum metabolites were more associated with LOMG, while the gut microbiota factors were more overlapping with EOMG.
3.4 Body Weight and Metabolic Factors
A large-scale two-sample Mendelian randomization study in European populations found that increased fresh fruit intake was associated with a reduced risk of MG (OR = 0.023, 95% CI = 0.001–0.683, p = 0.029). In contrast, higher body mass index (BMI) (OR = 2.696; 95% CI = 1.524–4.770; p < 0.001) and waist circumference were associated with increased risk of MG. Genetic susceptibility, immune dysregulation, and environmental factors all play pivotal roles in its pathogenesis.
3.5 Sedentary Behavior
Mendelian randomization analysis supports a causal effect of sedentary behavior as measured by leisure screen time (LST) on MG, indicating that lack of exercise may play a role in the development of MG. However, the same research noted that evidence of a causal effect of moderate-to-vigorous physical activity on MG risk was not substantial, and that longitudinal and interventional studies of this association remain warranted.
3.6 Associated Comorbid Autoimmune Conditions
Thymomas are not only associated with MG but also with pure red cell aplasia (approximately 4%), Isaac's syndrome (approximately 3%), systemic lupus erythematosus (approximately 2%), hypo-γ-globulinemia, myositis, stiff-person syndrome, rippling muscle disease, Morvan's syndrome, dermatomyositis, encephalitis, Hashimoto's thyroiditis, Graves' disease, Cushing's syndrome, Addison's disease, type 1 diabetes, paraneoplastic pemphigus, colitis, hepatitis, rheumatoid arthritis, and Sjögren's syndrome.
4. Nutritional Status and MG: General Considerations
Myasthenia gravis is a neuromuscular disorder that can impact various aspects of a patient's health, including nutritional status. Nutrition issues are common for patients with MG, potentially due to the difficulties the disease causes with swallowing (dysphagia).
Previous literature has focused primarily on symptoms and medical treatment. However, resources related to nutrition and myasthenia gravis are limited.
Although ESPEN (European Society for Clinical Nutrition and Metabolism) guidelines recognize that patients with myasthenia gravis may suffer from dysphagia, they do not provide disease-specific nutritional recommendations for MG. Thus, current clinical guidance on nutritional management remains limited.
5. Nutrients, Herbs, and Natural Ingredients
5.1 Vitamin D
Observational Evidence
Vitamin D has important roles both in the autoimmune response and in skeletal muscles. Researchers have investigated plasma levels of 25-hydroxy vitamin D [25(OH)D] in patients with MG and in healthy subjects to determine whether vitamin D deficiency is present in MG and whether vitamin D supplementation has beneficial effects on fatigue.
Plasma levels of 25(OH)D were analyzed in 33 patients with MG (22 males; mean age, 58 years) and in 50 healthy age- and sex-matched blood donors, without vitamin D3 medication. The MG composite (MGC) score assessed fatigue. Thirteen patients with MG without previous vitamin D3 supplementation were started on vitamin D3 supplementation (cholecalciferol) 800 IU/day, with a follow-up examination after 2.5–10 months (mean, 6 months).
A pilot study showed a correlation between lower serum vitamin D levels and MG prevalence, as well as autoimmune marker decrease and fatigue improvement after vitamin D3 supplementation with 800 IU/day, and 2 other studies demonstrated the role of vitamin D in the immune system in MG triggering and suppression.
One reviewed article shows an odds ratio of 3.96 (CI95 1.26 to 12.52), suggesting that myasthenia gravis patients had vitamin D levels almost 4 times lower than controls. However, literature on how vitamin D affects myasthenia gravis risk has not been widely studied and the results are still controversial.
Genetic Causality Evidence (Mendelian Randomization)
In a two-sample Mendelian randomization study using inverse variance weighting (IVW), circulating vitamin D levels had no causal effect on MG [OR = 0.91 (0.67–1.22), p = 0.532], and MG had no causal effect on circulating vitamin D [OR = 1.01 (0.99–1.02), p = 0.663]. No heterogeneity or pleiotropy was observed, and other MR methods also agreed with IVW results.
Due to the lack of studies with supra-physiological doses of vitamin D aiming to achieve pharmacological actions, strong evidence that vitamin D improves autoimmune diseases is yet to be shown. A single case report (PMC, 2016) described remission of severe MG following massive-dose vitamin D treatment, but this represents anecdotal evidence only and cannot be generalized.
Evidence strength summary: The association between low vitamin D status and MG is supported by small observational studies; however, Mendelian randomization analysis, which better controls for confounding, did not find a genetically predicted causal relationship. Evidence remains preliminary and conflicting.
5.2 Gut Microbiota, Probiotics, and Prebiotics
It is known that dysbiosis of the gut microbiome could lead to MG's clinical manifestations. Probiotics, prebiotics, and fecal microbiota transplants are potential microbiome therapies that could be explored and could provide significant benefits to MG patients.
The inflammatory microbiota may cause damage to intestinal epithelial cells and trigger an immune response, eventually leading to the occurrence of various autoimmune diseases and an imbalance in the immune system. Research explored the fecal microbiota of experimental autoimmune myasthenia gravis (EAMG) mice and healthy mice; at the phylum level, the ratio of Tenericutes/Verrucomicrobiota in the EAMG model group significantly decreased compared to controls, and partially recovered after probiotic treatment. At the family level, Lachnospiraceae decreased significantly in the EAMG group. After treatment with probiotics, the ratio of Ruminobacteriaceae to Lachnospiraceae decreased significantly.
Bacteriotherapeutic approaches such as pre- and probiotic supplements have been shown in some studies to slow disease progression. It should be noted that the evidence base for this claim draws primarily from animal models and small observational human data; no large-scale controlled human trials have been completed as of the time of the reviewed literature.
Evidence strength summary: Preclinical (animal) data and preliminary Mendelian randomization analyses provide theoretical support for a gut–immune axis in MG. Human interventional probiotic/prebiotic trial evidence is absent or extremely limited.
5.3 Omega-3 Fatty Acids
Omega-3 fatty acids, found in foods like fatty fish, walnuts, and flaxseeds, help regulate inflammation, support brain and cardiovascular health, and aid in cellular repair. Plant foods are rich in compounds that support overall health, including antioxidants and phytonutrients to help protect cells from damage, and fiber to support gut health, blood sugar regulation, and immune function.
No peer-reviewed clinical trials specifically investigating omega-3 supplementation as an intervention in MG were identified in the literature reviewed. The theoretical rationale for omega-3s in MG rests on their established immunomodulatory and anti-inflammatory properties in autoimmune disease generally; disease-specific human clinical trial evidence is lacking.
Evidence strength summary: Theoretical and general autoimmune-disease context only. No MG-specific human clinical trials identified in the peer-reviewed literature reviewed.
5.4 Calcium and Bone Health Nutrients
Calcium and vitamin D are especially important for individuals with MG who may be on long-term corticosteroids, which can increase the risk of bone loss. Calcium supports bone structure, while vitamin D helps the body absorb calcium. For this reason, it is recommended to have enough vitamin D in the diet or through limited sun exposure to ensure adequate calcium absorption.
This consideration is practical and mechanistically sound given the well-documented interaction between long-term corticosteroid use and bone mineral density, and is consistent with general clinical guidelines for corticosteroid-related osteoporosis prevention. However, it is not an MG-specific nutritional intervention per se, but rather a medication management consideration.
5.5 Fresh Fruit, Antioxidant-Rich Foods, and Plant-Based Diets
A large-scale Mendelian randomization study found that increased fresh fruit intake was associated with a reduced risk of MG (OR = 0.023, 95% CI = 0.001–0.683, p = 0.029). While this Mendelian randomization result is notable, it should be interpreted cautiously: the very wide confidence interval and the single study nature of this finding call for confirmation in additional independent cohorts.
There is some evidence to support that a whole food, plant-forward diet, like an anti-inflammatory or Mediterranean diet, could help manage disease symptoms.
6. Traditional Herbal Medicine in Myasthenia Gravis
6.1 Traditional Chinese Medicine (TCM): Historical and Theoretical Use
Traditional Chinese medicine considers MG to belong to the category of "flaccidity syndrome." Most studies show that the method of invigorating the spleen and replenishing qi is the key to the treatment of MG, and most practitioners use Buzhong Yiqi Decoction as the base prescription, which is treated according to syndrome differentiation.
According to TCM theory, Buzhong Yiqi Decoction (BYD) is a Qi-supplementing formula which is suitable for MG management, as MG is generally diagnosed as "flaccidity syndrome" and considered to be caused by Qi-deficiency.
In traditional Chinese medicine, myasthenia gravis belongs to the category of "impotence syndrome." The basic pathogenesis is described as the loss of essence and qi of the 5 internal organs, loss of vital blood and body fluid, and loss of tendon function unable to bind bones and benefit joints. Buzhong Yiqi decoction contains traditional Chinese medicines such as Radix Astragali, Atractylodes macrocephala, and Codonopsis pilosula, which are considered to strengthen the spleen and benefit the lung.
6.2 Scientific Evidence for TCM Formulas
A study enrolled 30 patients with myasthenia gravis divided into pretreatment and posttreatment groups, with 30 healthy volunteers serving as controls. The treatment group was treated with Modified Buzhong Yiqi Decoction (MBZYQD). After treatment, the antibody levels of AChR, MuSK, and Titin and the inflammatory factor levels of IL-6, IL-1β, and IL-22 in MG patients decreased significantly and nearly returned to a healthy level. In addition, the diversity, structure, and function of intestinal microorganisms in MG patients also recovered to a healthy level.
The main ingredients of MBZYQD are nine medicines, including Astragalus, Codonopsis, Atractylodes macrocephala, Cohosh, and Bupleurum chinense, among which the main active ingredients are flavonoids, including quercetin, luteolin, kaempferol, and naringenin. These active ingredients have anti-inflammatory and antioxidant effects.
Traditional Chinese medicine has shown great potential in MG treatment, including relief of muscle weakness syndrome, improvement of patient's quality of life, and reduction of side effects of western medicine. Published study protocols aim to evaluate the effectiveness of modified Buzhong Yiqi decoction as an add-on therapy for MG through N-of-1 trial designs.
Studies have shown that Buzhong Yiqi decoction combined with western medicine has a certain efficacy in the treatment of myasthenia gravis, but there is a lack of evidence-based medicine. The research objective is to systematically evaluate the efficacy and safety of Buzhong Yiqi decoction combined with western medicine in the treatment of myasthenia gravis, and to provide reliable evidence for guiding clinical practice.
Evidence strength summary: TCM formulas, particularly Buzhong Yiqi Decoction and its modifications, have a long history of traditional use in China for MG under the framework of "flaccidity syndrome" and "Qi deficiency." Small controlled clinical studies report improvements in antibody levels and inflammatory markers. However, most published studies are small, conducted at single centers, and lack rigorous blinding and standardization. Systematic review protocols have been registered but completed high-quality evidence remains limited. Results should be interpreted cautiously pending larger randomized controlled trials.
6.3 Active Botanical Compounds: Preclinical Investigations
The flavonoid compounds identified as active constituents in TCM formulas used for MG — including quercetin, luteolin, kaempferol, and naringenin — demonstrate anti-inflammatory and antioxidant effects in laboratory settings. As of the reviewed literature, the evidence for these individual compounds in MG is confined to preclinical (in vitro and in vivo animal model) levels, and no dedicated human clinical trials of these isolated phytochemicals in MG were identified.
7. Dietary Patterns and Lifestyle Factors
7.1 Dysphagia and Meal Planning
Myasthenia gravis is a neuromuscular disorder that can impact various aspects of a patient's health, including nutritional status. Nutrition issues are common for patients with MG, potentially due to the difficulties the disease causes with swallowing (dysphagia).
7.2 Anti-Inflammatory and Mediterranean Dietary Patterns
Due to the evidence-based links between MG and gut dysbiosis, a prebiotic-rich, high-fiber diet, possibly paired with probiotic supplementation, may be considered. There is some evidence to support that a whole food, plant-forward diet, like an anti-inflammatory or Mediterranean diet, could help manage disease symptoms.
Achieving nutritional adequacy in people with MG can be challenging because of fatigue and difficulty with chewing and swallowing (dysphagia).
7.3 Sedentary Behavior and Physical Activity
Mendelian randomization analysis supports a causal effect of sedentary behavior, as measured by leisure screen time, on MG, indicating that lack of exercise may play a role in the development of MG. Longitudinal and interventional studies of this association are warranted.
7.4 Body Weight
Higher body mass index (BMI) (OR = 2.696; 95% CI = 1.524–4.770; p < 0.001) and waist circumference (OR = 2.995; 95% CI = 1.457–6.156; p = 0.003) were associated with an increased risk of MG in Mendelian randomization analysis. This genetically anchored result suggests that metabolic and adiposity-related pathways may contribute to MG risk, though the underlying mechanisms require further investigation.
7.5 Nutritional Deficiency and Medication Interactions
Although ESPEN guidelines recognize that patients with myasthenia gravis may suffer from dysphagia, they do not provide disease-specific nutritional recommendations for MG. Medications commonly used in MG, such as corticosteroids, independently affect bone health, metabolic function, and body weight — considerations that inform the nutritional management of affected individuals but are driven by pharmacological rather than disease-specific nutritional mechanisms.
8. Summary of Evidence Levels
- Vitamin D and MG: Observational studies report lower vitamin D levels in MG patients and small pilot benefits from supplementation; however, Mendelian randomization analysis found no genetically predicted causal relationship. Evidence is preliminary and conflicting.
- Gut microbiota and MG: Causal links between specific gut microbial taxa and MG risk are supported by Mendelian randomization data; animal model probiotic interventions show effects; human clinical probiotic trials are absent or extremely limited.
- Fresh fruit / plant-based diet: One Mendelian randomization study (2025) found a statistically significant association between increased fresh fruit intake and reduced MG risk; expert commentary supports anti-inflammatory dietary patterns; no dedicated human dietary intervention trials in MG were identified.
- TCM formulas (Buzhong Yiqi Decoction): Long traditional use in China; small clinical studies report reductions in autoantibody levels and inflammatory markers; rigorous large-scale RCT evidence is lacking.
- Isolated phytochemicals (quercetin, luteolin, kaempferol, naringenin): Anti-inflammatory and antioxidant properties documented in laboratory settings; no dedicated human clinical trial evidence in MG.
- Omega-3 fatty acids: Theoretical rationale from general autoimmune research; no MG-specific clinical trials identified in the peer-reviewed literature reviewed.
- BMI and sedentary behavior: Mendelian randomization provides genetic-level evidence of a causal relationship between higher adiposity, sedentary behavior, and MG risk.
References
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