Definition

What Is Autoimmune Myositis?

Autoimmune myositis is a family of idiopathic inflammatory myopathies (IIMs) characterized by immune-mediated destruction of skeletal muscle. The immune system, through cytotoxic T-cells, autoantibodies and interferon-driven inflammation, targets muscle fibers, leading to proximal muscle weakness, elevated muscle enzymes (CK, LDH, aldolase), and, in some subtypes, life-threatening lung, heart and skin involvement.

The disease spectrum includes polymyositis (diffuse muscle inflammation without skin involvement), dermatomyositis (muscle inflammation with characteristic skin rashes such as heliotrope rash and Gottron's papules), inclusion body myositis (a slowly progressive form predominantly affecting men over 50, with distal muscle involvement) and antisynthetase syndrome (PM/DM with interstitial lung disease, mechanic's hands and Raynaud's phenomenon, triggered by anti-Jo-⁠1 or related autoantibodies).

⚠️ Important: Autoimmune myositis requires diagnosis and monitoring by a rheumatologist or neurologist. Interstitial lung disease (ILD), a serious complication of dermatomyositis and antisynthetase syndrome, needs emergency care the same day when breathlessness or a dry cough is new or getting worse. The nutritional strategies here are evidence-informed adjuncts to, not replacements for, medical care. Do not discontinue immunosuppressive medications without physician guidance.

A front view of a body drawn with its muscles, and a close-up circle of inflamed muscle fibers with immune cells crowding between them

Types & Subtypes

Polymyositis (PM)

CD8+ cytotoxic T-cells invade non-necrotic muscle fibers, causing symmetric proximal muscle weakness (hip flexors, shoulder girdle) without skin involvement. Affects adults predominantly (rarely children). CK is markedly elevated (typically 5 to 50 times normal). Dysphagia (difficulty swallowing) occurs in about 36% of people with myositis¹. Associated with a smaller increase in cancer risk than dermatomyositis¹⁰; cancer screening at diagnosis, guided by age, symptoms and antibodies, is standard². Responds better to immunosuppression than dermatomyositis in most patients.

Dermatomyositis (DM)

Complement-mediated destruction of muscle capillaries, driven by plasmacytoid dendritic cells and type-I interferon, causing muscle inflammation and characteristic skin manifestations: heliotrope rash (violaceous discoloration of eyelids), Gottron's papules (raised, scaly papules over knuckle joints), "shawl sign," "V-sign" and mechanic's hands. Anti-MDA5 DM carries a high risk of rapidly progressive interstitial lung disease (RPILD), a medical emergency. Anti-TIF1γ DM has the highest malignancy association: in a meta-analysis of 69 studies, people with anti-TIF1γ antibodies had 4.7 times the cancer risk of those without them³. UV avoidance is crucial: UV triggers type-I interferon release.

Inclusion Body Myositis (IBM)

The most common inflammatory myopathy in those over 50, IBM is unique: it preferentially affects the finger flexors and the knee extensors (quadriceps), causes slowly progressive weakness over years to decades, has CK levels that are only mildly elevated (2 to 10 times normal), and is almost entirely resistant to all immunosuppressive treatments, making it the most challenging subtype. There is no proven disease-modifying therapy for IBM; supervised exercise⁴ is the main measure for preserving function.

Signs & Symptoms

Symptoms of Autoimmune Myositis

Autoimmune myositis presents across a spectrum from subtle muscle aching and fatigue to rapidly progressive weakness, respiratory failure and multi-organ involvement. Early recognition of red flag symptoms is critical, particularly signs of interstitial lung disease and cardiac involvement.

Symptom	What happens
Primary Muscle & Systemic Signs
Proximal Muscle Weakness	The hallmark of PM and DM: symmetrical weakness of the proximal muscles, difficulty rising from a chair without using arms, climbing stairs, lifting objects above shoulder height or combing hair. Weakness develops over weeks to months. Weakness without significant pain is a key feature that often delays diagnosis.
Dysphagia & Dysphonia	Involvement of pharyngeal and upper esophageal muscles causes difficulty swallowing (dysphagia) in about 36% of people with myositis and 56% of those with inclusion body myositis, often the most functionally disabling symptom¹. Nasal regurgitation of liquids, choking on food and a sensation of food sticking in the throat are typical. Aspiration pneumonia is a serious complication and a major cause of disease mortality. Dysphagia in myositis requires formal swallowing evaluation (modified barium swallow) and usually a speech-language pathologist consultation.
Profound Fatigue & Functional Decline	Disproportionate fatigue, beyond what muscle weakness alone explains, is common in autoimmune myositis. It is part of the disease, not simply deconditioning, and can include worsening after effort and poor concentration. Fatigue is often the symptom most resistant to immunosuppressive treatment, which is why supervised exercise and good sleep matter.
Skin, Lung & Cardiac Red Flags
Dermatomyositis Skin Rashes	Heliotrope rash: violaceous (lilac-purple) discoloration of the upper eyelids, often with periorbital edema, pathognomonic for DM. Gottron's papules: raised, erythematous, scaly papules overlying the metacarpophalangeal and interphalangeal joints, the most specific skin sign. "V-sign": erythema of the anterior chest and neck in a V-shaped distribution. "Shawl sign": erythema of the upper back and shoulders. Mechanic's hands: cracking, fissuring and hyperpigmentation of the radial aspect of the fingers, associated with antisynthetase syndrome and anti-Jo-⁠1 antibody.
Interstitial Lung Disease (ILD), Emergency	ILD occurs in about 41% of people with PM/DM worldwide, about a quarter in Europe and the Americas, and is the most important factor in myositis-related deaths⁶. Anti-MDA5 DM can cause rapidly progressive ILD with respiratory failure within weeks. Symptoms: breathlessness on exertion, dry cough and reduced exercise tolerance. No diet or supplement has been shown to prevent or slow ILD; it is managed with specialist respiratory care.
Cardiac Involvement	Heart involvement is often silent, detected only by cardiac MRI or Holter monitoring. Patients with dyspnea, palpitations or peripheral edema require echocardiography. Cardiac involvement is managed by cardiology; no supplement has been shown to treat it.

Diagnosis

How Autoimmune Myositis Is Diagnosed

Diagnosis combines symptoms, muscle enzymes, antibodies, imaging and biopsy. Ongoing monitoring tracks disease activity and treatment response, and identifies the complications (ILD, malignancy, cardiac involvement) that determine prognosis.

Test	What it shows
Diagnostic Testing
Muscle Enzyme Panel	Creatine kinase (CK), the primary marker of muscle damage; typically 5 to 50 times normal in PM/DM, 2 to 10 times in IBM. Aldolase, elevated; adds sensitivity when CK is mildly elevated or normal (can occur in DM). Lactate dehydrogenase (LDH) and AST, also elevated from muscle tissue, not liver. Troponin-I checks for heart involvement. The CK trend, falling with effective treatment and rising with relapse, is the most useful activity marker.
Myositis-Specific Autoantibodies (MSAs)	MSAs define clinical subtypes and predict prognosis: Anti-Jo-⁠1, antisynthetase syndrome with ILD, arthritis, mechanic's hands, fever, Raynaud's; anti-MDA5, DM with high ILD risk (rapidly progressive); anti-TIF1γ, DM with highest cancer association; anti-Mi-⁠2, classic DM, good treatment response; anti-SRP, necrotizing myopathy, severe weakness; anti-HMGCR, statin-triggered necrotizing myopathy. A comprehensive MSA panel should be performed at diagnosis; results directly inform treatment decisions and cancer screening intensity.
Muscle MRI (STIR Sequence)	MRI with a STIR sequence is the most sensitive non-invasive marker of active muscle inflammation, and can show it when CK is normal. It guides the biopsy site, tracks response and separates active myositis from steroid-induced weakness or scarring.
Complication Screening
Pulmonary Function & HRCT	High-resolution CT (HRCT) of the chest detects ILD and monitors its progression. Pulmonary function tests, including diffusing capacity (DLCO) and lung volume (FVC), measure ILD severity and track response to treatment. Perform at diagnosis, 3 to 6 months into treatment and annually thereafter. In anti-MDA5 DM, HRCT and PFTs should be performed urgently at diagnosis given the risk of rapidly progressive ILD.
Malignancy Screening	Myositis, particularly DM and anti-TIF1γ-positive disease, is significantly associated with occult malignancy, especially in adults over 40. Cancer risk is highest in the 3 years before and after diagnosis. Recommended screening: CT chest/abdomen/pelvis with contrast, full-body skin examination, CEA, CA-⁠125 (women), PSA (men), colonoscopy, mammography, transvaginal ultrasound (women). PET-CT is increasingly used in high-risk patients (anti-TIF1γ positive, refractory disease) for comprehensive malignancy surveillance. Malignancy-associated myositis may respond poorly to immunosuppression until the cancer is treated.
Functional & Nutritional Assessment	Vitamin D (25-⁠OH-D): deficiency is common, especially on steroids; target set with your clinician.

Treatment Comparison

Conventional and Holistic Treatment for Autoimmune Myositis

🌿 HOLISTIC

💊 CONVENTIONAL

🌿

Holistic / Functional Approach

Diet, supplements and supervised exercise, alongside medical treatment

Anti-Inflammatory Diet Evidence

A Mediterranean-style pattern is reasonable and well tolerated¹⁶, but evidence for any diet in inflammatory myopathies remains limited, and most studies have tested supplements rather than whole diets⁷

Gut-Immune Axis

Changing gut bacteria has not been shown to help

Muscle Preservation

Creatine with exercise improved function in one 6-⁠month trial¹⁷

Advantage

Counters steroid side effects on bone, muscle and blood sugar and supports exercise; none of it treats the disease itself or replaces medical treatment

Full Holistic Approach Includes

Creatine Monohydrate (20 g/day for 8 days, then 3 g/day, pure pharmaceutical grade), with exercise, the regimen used in the trial¹⁷; not shown to help IBM. Contraindications: kidney disease. Use with at least 8 cups (2 L) of water a day
Gut-directed supplements, Saccharomyces boulardii 250 mg (about 5 billion CFU) a day during antibiotic courses; prebiotic fiber (partially hydrolyzed guar gum, acacia fiber, 10 to 15 g/day); a multi-strain probiotic; L-glutamine (10 g/day). None has been tested in myositis. On immune-suppressing treatment or with a central line, take a live probiotic (S. boulardii or a multi-strain product) only with your specialist team's agreement, as yeast bloodstream infections have been reported.
Magnesium glycinate or malate (400 to 600 mg/day elemental). This whole range is above the 350 mg/day upper intake level for supplemental magnesium; above that, diarrhea is common. With kidney disease, take it only on your clinician's advice.
Resistance exercise (supervised, low-to-moderate intensity): this does not worsen myositis and is recommended to improve function, led by a specialist physical therapist¹³; 2 to 3 sessions/week, 60 to 70% of the most you can lift once (1RM), with rest-day monitoring

💊

Conventional / Medical Approach

High-dose corticosteroids, methotrexate, azathioprine, mycophenolate mofetil, IVIG, rituximab, JAK inhibitors

Corticosteroids (First-Line)

Oral prednisone 0.5 to 1 mg/kg/day, usually 40 to 60 mg, is the initial treatment, tapered according to clinical response¹⁸

Steroid-Sparing Agents

Several disease-modifying medicines, listed with their doses below, are used to control disease and reduce steroid dose; no single agent is established as first choice¹⁸

Refractory Disease

Immunoglobulin, B-cell therapy or, with limited evidence, JAK-pathway medicines; doses and cautions below

Side Effects

Long-term prednisone: steroid myopathy, osteoporosis¹⁹, diabetes, hypertension, cataracts, adrenal suppression, weight gain, immune suppression. Methotrexate: hepatotoxicity, teratogenicity, pulmonary toxicity. Azathioprine: bone marrow suppression, hepatotoxicity, lymphoma risk. IVIG: headache, renal toxicity, thrombosis, cost ($10,000 to $50,000/course)

Conventional Approach Includes

High-dose prednisone (0.5 to 1 mg/kg/day, usually 40 to 60 mg/day), must be combined from the start with calcium (1,200 mg), vitamin D (commonly 800 to 2,000 IU/day; the adult upper intake level is 4,000 IU/day) and a bisphosphonate (alendronate) to prevent steroid-induced osteoporosis; PPI for gastric protection; blood glucose monitoring. Tapering typically begins at 4 to 8 weeks once CK normalizes and strength improves, in gradual steps set by your specialist, and must be individualized to prevent relapse
Methotrexate (15 to 25 mg/week, oral or subcutaneous), the most widely used steroid-sparing agent; weekly dosing with daily folic acid (1 to 5 mg) to reduce toxicity, a prescribed pairing that deliberately exceeds the 1,000 mcg upper intake level for folic acid and is correct in this context; monitor CBC and LFTs regularly.
Azathioprine (150 to 200 mg/day, weight-based), check TPMT enzyme level before starting (poor metabolizers have profound bone marrow toxicity); gradual dose escalation; monitor CBC monthly; 6 to 12 weeks for clinical effect.
Mycophenolate mofetil (2 to 3 g/day in 2 divided doses), monitor CBC and LFTs
IVIG (Intravenous Immunoglobulin, 2 g/kg over 2 to 5 days, monthly for 3 cycles), FDA-approved (2021) for dermatomyositis; particularly useful during pregnancy, in patients with severe dysphagia or during infection when other immunosuppressants must be withheld.
Rituximab (1 g IV x 2 doses 2 weeks apart, or 375 mg/m² weekly x 4), in a trial of 200 adults and children with refractory myositis, 83% met the definition of improvement over 44 weeks, whether treated early or late²⁰; response may be delayed 3 to 6 months; repeat dosing every 6 months if effective. Monitor for PML (progressive multifocal leukoencephalopathy) in long-term users
JAK inhibitors (tofacitinib 5 mg twice a day, ruxolitinib 10 to 20 mg twice a day), block interferon-driven signaling; not approved for myositis, with too little evidence for the specialist guideline to recommend them, though case series are promising¹³; monitor for opportunistic infections, VTE and lymphoma risk (class effect)

⚠️ Steroid consideration: Long-term corticosteroid therapy, while essential for initial disease control, paradoxically causes steroid myopathy, worsening the very muscle weakness it is treating. This makes adequate protein and supervised exercise worth starting early, not after treatment has settled. On these medicines live vaccines may need to be avoided, so ask your specialist before any vaccine²¹.

Nutritional Strategy

Diet for Autoimmune Myositis

The myositis diet's clearest job is providing the protein, calcium and vitamin D that protect muscle and bone under steroid therapy¹⁹; evidence for any diet in inflammatory myopathies remains limited⁷.

Muscle-protective foods for myositis, and what to limit

What to eat or do	Details
✅ Eat More Of:
Warm turmeric-ginger broth or golden milk	A pleasant warm drink rather than a treatment.
High-protein anti-inflammatory breakfast: eggs with wild salmon, or a Greek yogurt smoothie	30 to 40 g protein at breakfast to counter the muscle breakdown steroids cause; leucine-rich protein stimulates muscle protein synthesis.
Wild fatty fish 5x/week (salmon, sardines, Atlantic mackerel, herring)	For protein and omega-⁠3 fats; untested as a myositis treatment.
Cruciferous vegetables daily (broccoli, kale, Brussels sprouts, cauliflower)	Part of a varied, vegetable-rich pattern.
Extra-virgin olive oil as primary fat (3 to 4 tbsp/day)	For its oleocanthal, which inhibits COX enzymes in laboratory studies; a typical daily intake of olive oil provides a small fraction of an ibuprofen dose, so this is a dietary contribution rather than a substitute for anti-inflammatory medication.¹⁶
Colorful vegetables & prebiotic foods (sweet potato, beets, chicory, Jerusalem artichoke)	For fiber and variety.
Raw garlic (2 to 3 cloves) or aged garlic extract	Anti-inflammatory in laboratory studies only.
Green tea 2 to 3 cups or EGCG 400 mg	Anti-inflammatory in laboratory and animal studies only. Green tea extract capsules have been linked to liver injury, so ask your team before taking one alongside liver-monitored medicines.²²
1.6 to 2 g protein per kg bodyweight daily	Steroids speed up muscle breakdown; leucine-rich sources include eggs, fatty fish, chicken and legumes. With kidney disease, your clinician sets the protein amount instead.²³
Fermented foods daily (plain coconut yogurt, kimchi, sauerkraut, kefir if tolerated)	As part of a varied diet; unpasteurized kinds carry live bacteria, but on immune-suppressing treatment choose pasteurized products, since treatments such as steroid tablets raise the risk of serious foodborne infection.²⁴
Dark chocolate ≥85% (20 to 30 g/day)	A source of flavanols and magnesium.
Nightshades (tomatoes, peppers, eggplant, potatoes)	No evidence in myositis that removing them helps, so there is no need to avoid them.
❌ Avoid or Reduce:
Gluten (wheat, barley, rye)	Avoid if you have celiac disease; otherwise there is no evidence that removing gluten helps myositis.
Processed sugar and refined carbohydrates	Worsen blood sugar control, which steroids already raise.
Deep-fried and ultra-processed foods	Worth limiting for general health.
Alcohol	Avoid alcohol during active disease and while taking methotrexate, since together they can damage the liver.

What to eat or do	Details
Other Foods Often Suggested
Tart Cherry	Tart cherry has been studied for exercise soreness in healthy people, not in myositis, and provides a little melatonin. 2 tablespoons (30 mL) tart cherry concentrate or 480 mg extract daily.
Flaxseed (Ground)	Ground flaxseed provides ALA omega-⁠3 and soluble fiber. 2 tablespoons daily ground fresh (pre-ground oxidizes rapidly).
Edamame & Tempeh	Complete plant protein with leucine content for muscle protein synthesis.

Supplement Protocol

Evidence-Based Supplements for Autoimmune Myositis

Only creatine, taken with exercise, has a trial in myositis¹⁷; the rest address steroid side effects, deficiency or laboratory reasoning only⁷. Always review with your rheumatologist for interactions with immunosuppressive medications.

Supplement	What it is for	Typical range	Timing	Notes & cautions
Vitamin D3 + K2-⁠MK7	Vitamin D matters here mainly for bone under steroid treatment¹⁹, and deficiency is common on steroids; its immune effects come from laboratory work, not from trials in myositis. K2 has not been shown to prevent calcinosis or hypercalcemia; keep vitamin D within the dose your clinician sets.	Vitamin D3: test 25-⁠OH-D first and set the dose with your clinician; K2-⁠MK7: 180 to 360 mcg/day	With the largest fat-containing meal (both fat-soluble)	Test 25-⁠OH-D at baseline and every 3 months when supplementing, and agree on any target with your clinician. Dosing limits: the adult tolerable upper intake level is 4,000 IU/day. The Endocrine Society's 2024 guideline found no clear evidence for an optimal target level; the National Academies (formerly the Institute of Medicine) set sufficiency at 20 ng/mL (50 nmol/L). Any dose above 4,000 IU/day needs a blood test and a clinician, not a self-directed dose. Monitor calcium and PTH annually if your clinician has you above the upper intake level. Interactions: corticosteroids lower vitamin D and impair calcium absorption, so steroid-treated patients need higher replacement doses. If you take warfarin, clear any vitamin K supplement with the clinician managing your anticoagulation before starting or stopping it: vitamin K antagonizes warfarin, and changing your intake destabilizes the INR.
Omega-⁠3 (EPA + DHA)	EPA and DHA lower inflammatory signaling in laboratory work and in other autoimmune diseases; they have not been tested in myositis.	4 to 6 g EPA + DHA/day	With the largest fat-containing meal; split doses improve tolerance	Triglyceride-form fish oil is better absorbed than ethyl esters. Refrigerate after opening. Monitor omega-⁠3 index at 3 months, target above 8%. At doses above 4 g/day, monitor for blood thinning if on anticoagulants. The top of this range is above 5 g a day, the most EPA and DHA (from food and supplements together) that the FDA considers safe; check any dose over 5 g with your clinician. In heart trials, fish oil supplements raised the risk of atrial fibrillation, an irregular heartbeat, more so above 1 g a day²⁵, so check this dose with your clinician first.
Curcumin	Curcumin inhibits NF-κB and JAK-STAT signaling in laboratory work; it has not been tested in myositis. The more absorbable forms of curcumin have been linked to liver damage in some people: stop and tell your team if you notice tiredness, nausea, dark urine or yellowing skin²⁶.	500 to 1,000 mg curcumin/day	With fat-containing meals (fat improves absorption); divide into 2 doses	Curcumin may potentiate warfarin; monitor INR if on anticoagulation. May also potentiate the immunosuppressive effect of tacrolimus in theory; monitor with rheumatologist. Start at 500 mg and increase over 2 weeks (loose stools possible initially at higher doses).
CoQ10 Ubiquinol	CoQ10 is part of the mitochondrial energy chain, and mitochondrial changes are seen in muscle biopsies in myositis; whether taking it helps has not been shown. Its trial evidence in heart disease comes from heart failure, not myocarditis, and results for statin muscle symptoms are mixed. It is not a treatment for myositis²⁷.	400 to 600 mg Ubiquinol/day	Divided into 2 doses with fat-containing meals	Ubiquinol may be better absorbed than ubiquinone. Choose a third-party tested product. No effect on myositis fatigue or CK has been shown. Safe long-term; no known interactions with immunosuppressive medications at standard doses.
Creatine Monohydrate	In a 6-⁠month randomized trial in 37 people with polymyositis or dermatomyositis, creatine (20 g/day for 8 days, then 3 g/day) with home exercise improved high-intensity function more than exercise alone, without significant side effects. It has not been shown to help inclusion body myositis.	20 g/day for 8 days, then 3 g/day (the regimen used in the trial)	Post-exercise on exercise days; with any meal on rest days	Use plain creatine monohydrate with third-party testing; avoid creatine ethyl ester or buffered forms (inferior evidence). Requires at least 8 cups (2 L) of water a day. Contraindicated in kidney disease; check creatinine and GFR before starting. The loading phase can cause GI discomfort; discuss the regimen with your clinician.
NMN or NR (NAD+ Precursors)	NAD+ is a cofactor for mitochondrial energy production. NMN (nicotinamide mononucleotide) and NR (nicotinamide riboside) raise NAD+ levels, but human trials are small and have not included myositis.	NMN: 500 to 1,000 mg/day or NR: 500 to 1,000 mg/day	Morning on empty stomach or with light breakfast	Look for third-party tested products. Avoid combining high-dose NAD+ precursors with niacinamide (which inhibits SIRT1 at high concentrations). Monitor liver enzymes at 3 months if using doses above 1 g/day.
Magnesium Glycinate or Malate	Magnesium is needed for energy production and muscle contraction and relaxation, and low levels can cause cramping. Magnesium malate has been studied for widespread muscle pain in other conditions, not in myositis.	400 to 600 mg elemental magnesium/day	Divided: 200 mg with dinner, 200 to 400 mg before bed	Magnesium glycinate and malate are gentler on the gut; avoid magnesium oxide (poorly absorbed, causes diarrhea). Red blood cell (RBC) magnesium, not serum, reflects tissue stores. Target RBC magnesium above 5.5 mg/dL. This whole range is above the 350 mg/day upper intake level for supplemental magnesium; above that, diarrhea is common. With kidney disease, take it only on your clinician's advice.
Alpha-Lipoic Acid (R-ALA)	R-ALA is a mitochondrial cofactor and antioxidant in laboratory work, and it improves insulin sensitivity, which matters because steroids raise blood sugar; it has not been tested in myositis.	300 to 600 mg R-ALA/day (R form is twice as bioavailable as racemic ALA)	On empty stomach 30 minutes before meals; food reduces absorption; ALA may compete with biotin for transport	Do not add a biotin supplement to make up for this without asking first: high-dose biotin interferes with some blood tests, including troponin. Choose a third-party tested product. Do not take with insulin or hypoglycemic agents without monitoring (ALA improves insulin sensitivity). If using with methotrexate, monitor LFTs.

References & Evidence Notes

Each numbered entry below is either a source you can follow or a note setting out what the evidence does and does not support. Both are numbered together so the markers in the text line up.

Last reviewed October 20, 2026. Supplement entries are cross-checked against the NIH National Center for Complementary and Integrative Health and the Linus Pauling Institute Micronutrient Information Center.³¹ Two things frame this page. First, myositis is treated with immunosuppression, and the treatment is what preserves muscle and lung function. Nothing here replaces it, and tapering or stopping steroids or immunosuppressants without your rheumatologist risks a flare that costs function permanently. Second, the complication that matters most is often not the muscle: interstitial lung disease is a leading cause of death in myositis, particularly with antisynthetase and anti-MDA5 antibodies, so new or worsening breathlessness or cough needs emergency care the same day rather than being attributed to deconditioning. Difficulty swallowing also deserves urgent attention, because it carries aspiration risk. Nutrition genuinely helps with steroid side effects, bone protection and muscle preservation.

On swallowing: a systematic review of 234 studies, with a meta-analysis of 116 studies covering 10,382 people, estimated trouble swallowing in 36% of people with inflammatory myopathy and 56% of those with inclusion body myositis, higher still with cancer-associated myositis. It can cause aspiration pneumonia, which raises mortality, PubMed 32650400. ↩
On cancer screening: dermatomyositis in particular carries an increased risk of underlying malignancy, concentrated in the years around diagnosis and higher with certain antibodies such as anti-TIF1γ, which is one of five factors in a published model for predicting which patients have an underlying cancer, PubMed 41335433. Age-appropriate and antibody-guided cancer screening at diagnosis is standard and is sometimes missed. ↩
On who is at highest cancer risk: a meta-analysis of 69 studies within inflammatory myopathy found cancer risk raised with dermatomyositis, older age, male sex, swallowing trouble, skin ulceration and, most strongly, anti-TIF1γ antibodies (4.7 times the risk of those without them), and lower with anti-Jo-⁠1 antibodies and lung disease; CT of the chest, abdomen and pelvis appeared useful for screening, PubMed 33599244. ↩
On exercise: supervised exercise was once avoided in active myositis and is now recommended. Randomized and observational evidence supports resistance and aerobic training improving strength and function without increasing inflammation, including in active disease when appropriately supervised; a multicenter randomized trial in recent-onset disease found high-intensity interval training improved aerobic capacity more than moderate exercise, with disease activity tracked as a safety outcome, PubMed 41314147. This is a reversal of older advice and it matters. ↩
On what shapes who gets it: a systematic review of 46 incidence and prevalence studies confirmed that inflammatory myopathies are rare, found that inclusion body myositis tracks the frequency of the immune gene type HLA-DR3, that dermatomyositis may follow a latitude gradient consistent with an effect of ultraviolet light, and that the seasonal timing of juvenile myositis is consistent with a role for infection, PubMed 25065005. ↩
On lung involvement: a meta-analysis of 34 studies covering 10,130 people with polymyositis or dermatomyositis found interstitial lung disease in about 41% overall (42% in dermatomyositis, 35% in polymyositis), with wide regional variation, about half in Asia and about a quarter in Europe and the Americas. Lung disease is the most important factor in myositis-related deaths, and anti-Jo-⁠1 and anti-MDA5 antibodies carry the highest risk, PubMed 33383294. ↩
On diet in inflammatory myopathies: a 2026 systematic review of nutritional interventions in muscle diseases found that most studies tested supplements rather than whole diets, and concluded that the evidence remains limited, especially for inflammatory myopathies, PubMed 42482152. ↩
On the overall picture: NHS guidance says myositis is a group of rare conditions causing muscle weakness, that most types are autoimmune and genes may play a part, that treatment with steroids and other medicines to stop the immune attack, plus physical therapy, helps control the symptoms rather than ending the condition, and that swallowing and breathing problems can occur, NHS, myositis. ↩
On who is affected: a population-based study of adults with dermatomyositis and polymyositis in Colombia, using national health records from 2018 to 2021, found a prevalence of 8.3 per 100,000, a female to male ratio of 2.4 to 1 and an average age of 51.5 years, PubMed 41108005. ↩
On the cancer link: a pooled analysis of national registers in Sweden, Denmark and Finland found cancer in 198 of 618 adults with dermatomyositis, three times the expected rate, with ovarian, lung, pancreatic, stomach and colorectal cancers and lymphoma most raised; polymyositis carried a smaller excess. In both, the risk was highest at the time the myositis was diagnosed, PubMed 11197446. ↩
On the conditions: idiopathic inflammatory myopathies include dermatomyositis, polymyositis, immune-mediated necrotizing myopathy and inclusion body myositis, which behave differently. Myositis-specific antibodies define clinically meaningful subgroups and predict complications, including interstitial lung disease and malignancy risk, which is why antibody testing changes management rather than being academic. ↩
On cause and outlook in dermatomyositis: NIH patient guidance says the cause is unknown, that a viral infection of the muscles or an immune problem has been proposed, that it can occur in people with cancer, and that when a tumor is causing it, the weakness and rash may improve once the tumor is removed; cancer and lung disease are the main causes of death, MedlinePlus, dermatomyositis. ↩
On the specialist guideline: the 2022 British Society for Rheumatology guideline recommends high-dose steroid tapered by response, disease-modifying medicines to reduce inflammation and steroid burden, immunoglobulin or B-cell therapy for refractory disease, and an exercise program led by a specialist physical therapist. It advises considering cancer risk in every adult and screening those at higher risk, screening high-risk patients for lung disease, a bone health assessment for everyone, routine questions about swallowing because aspiration can be fatal, and sun avoidance with high-SPF sunscreen in dermatomyositis, since sun exposure is linked to flares. It found insufficient evidence to recommend JAK-pathway medicines, though case series are promising, PubMed 35355064. ↩
On cholesterol-lowering medicines: a multicenter study of 1,250 people with inflammatory myopathy and 656 controls confirmed that anti-HMGCR antibodies, found alongside statin use, mark a subset of myositis in older people with muscle necrosis on biopsy, and that testing for them matters in diagnosis, PubMed 27491568. ↩
On cancer immunotherapy: a pooled analysis of 136 people with myositis overlapping with heart and nerve-muscle involvement after immune checkpoint inhibitor treatment found symptoms began a median of 22 days after the first dose and that 39% died in the hospital, PubMed 42591394. ↩
On olive oil and anti-inflammatory eating: oleocanthal inhibits COX enzymes in laboratory studies, and the frequently repeated comparison with ibuprofen refers to a fraction of an ibuprofen dose from a substantial quantity of oil. A Mediterranean-style pattern is reasonable and well tolerated; it is a dietary contribution and not an anti-inflammatory drug. ↩
On creatine: in a six-month randomized placebo-controlled trial of 37 people with polymyositis or dermatomyositis who were still weak on stable treatment, creatine (20 g a day for 8 days, then 3 g a day) with a home exercise program improved high-intensity functional performance more than exercise with placebo, without significant adverse effects, PubMed 17471547. The trial enrolled polymyositis and dermatomyositis only, not inclusion body myositis. ↩
On initial and steroid-sparing treatment: the 2022 British Society for Rheumatology guideline recommends oral prednisolone (the UK counterpart of prednisone) at 0.5 to 1 mg/kg a day, usually 40 to 60 mg, for active muscle inflammation in adults, tapered according to clinical response. It lists methotrexate, azathioprine, tacrolimus, cyclosporine and mycophenolate mofetil as options for active disease and long-term maintenance, and says the evidence does not allow any one of them to be ranked first, PubMed 35355064. ↩
On steroid side effects, where nutrition does concrete work: long-term glucocorticoids cause bone loss, and bone protection with calcium, vitamin D and, where indicated, a bisphosphonate is standard alongside steroid initiation rather than after a fracture. Steroids also drive muscle loss, hyperglycemia and weight gain, so adequate protein and resistance exercise, once cleared, counteract exactly what the drug does. ↩
On treatment for disease that has not responded: in a randomized trial of 200 adults and children with refractory myositis, starting a B-cell depleting treatment early or 8 weeks later made no difference to the time to improvement, but 83% of all participants met the definition of improvement over the 44-⁠week trial, PubMed 23124935. ↩
On vaccines during immune-suppressing treatment: NHS guidance says live vaccines, such as the chickenpox vaccine, are not recommended for people whose immune system is weakened by an illness or a treatment, and advises people on immune-suppressing medicines to keep having the vaccines they are invited for but to tell the person giving them about the medicine, as some vaccines may not be suitable, NHS, chickenpox vaccine and NHS, immune-suppressing medicine questions. ↩
On green tea extract and the liver: NIH guidance says liver injury, although uncommon, has been reported in some people who used green tea products, mainly green tea extract in tablet or capsule form, rather than green tea drunk as a beverage, NCCIH, green tea. ↩
On protein and the kidneys: NIH guidance says some people with chronic kidney disease need moderate amounts of protein so waste does not build up in the blood, while too little risks malnutrition, and advises working with a dietitian or clinician to find the right amount, NIDDK, eating right for kidney disease. ↩
On food safety during immune-suppressing treatment: NHS guidance says people having treatment that weakens the immune system, such as steroid tablets, are at higher risk of serious illness from listeria, which is mostly caught from chilled ready-to-eat foods, including dairy products made from unpasteurized milk, NHS, listeriosis. ↩
Gencer B, Djousse L, Al-Ramady OT, Cook NR, Manson JE, Albert CM. Effect of long-term marine omega-⁠3 fatty acids supplementation on the risk of atrial fibrillation in randomized controlled trials of cardiovascular outcomes: a systematic review and meta-analysis. Circulation. 2021;144(25):1981-⁠1990. PubMed 34612056. Seven trials with 81,210 people followed for about 5 years: omega-⁠3 supplements were linked to a higher risk of atrial fibrillation (hazard ratio 1.25), more so in trials of more than 1 g a day (1.49), and the risk rose with each additional gram. ↩
On turmeric and the liver: NIH guidance says it is not known whether turmeric or curcumin helps any health condition, that highly bioavailable curcumin formulations may harm the liver, and that anyone who notices tiredness, nausea, poor appetite, dark urine or yellowing of the skin or eyes should stop taking it and talk to their clinician, NCCIH, turmeric. ↩
On statins and creatine kinase: statin-associated muscle symptoms and, rarely, immune-mediated necrotizing myopathy with anti-HMGCR antibodies can complicate the picture. Any statin history belongs in the assessment. Coenzyme Q10 is often used for statin-associated muscle symptoms, with trial results that are mixed at best, and it is not treatment for myositis. ↩
On fast-moving lung disease: a meta-analysis of 18 studies covering 6,058 adults with dermatomyositis or polymyositis found rapidly progressive interstitial lung disease in about 8.9%, with a poor long-term outlook, which is why new breathlessness or cough needs urgent assessment, PubMed 37164215. ↩
On breathing emergencies: NHS guidance advises calling emergency services or going to an emergency department immediately for severe difficulty breathing, gasping, choking or being unable to get words out, and not driving yourself, NHS, shortness of breath. ↩
On infection during immune-suppressing treatment: NHS guidance for one of the steroid-sparing medicines used in myositis advises telling your doctor or calling for urgent advice immediately for a high temperature, feeling hot, cold or shivery, muscle aches or a sore throat, which may be signs of infection, NHS, medicine side effects. ↩
National Center for Complementary and Integrative Health (NIH), nccih.nih.gov, and the Linus Pauling Institute Micronutrient Information Center, lpi.oregonstate.edu/mic. ↩

Cause	How It Contributes to Autoimmune Myositis	What Helps
Genes and immune makeup	It is not clear what causes myositis, but genes may play a part⁸; inclusion body myositis is more common where a particular immune gene type (HLA-DR3) is more frequent⁵	Immune-suppressing treatment from a specialist controls the autoimmune forms; no diet or supplement on this page changes the immune attack
Cancer, in adults with dermatomyositis	Adult dermatomyositis is strongly linked with cancer, particularly ovarian, lung, pancreatic, stomach and colorectal cancers and lymphoma, with the risk highest around diagnosis¹⁰; older age, male sex, swallowing trouble, skin ulcers and anti-TIF1γ antibodies raise it further³	Cancer screening at diagnosis, guided by age, symptoms and antibodies, as the diagnosis section describes; when a tumor is driving the myositis, treating it can improve the weakness and rash¹²
Sunlight, in dermatomyositis	Sun exposure is linked to flares of dermatomyositis affecting both skin and muscle¹³	Sun avoidance and regular high-SPF broad-spectrum sunscreen, which the specialist guideline suggests to reduce flares¹³
Medicines	Cholesterol-lowering statins can trigger a necrotizing form of myositis marked by anti-HMGCR antibodies, mostly in older people¹⁴; immune checkpoint inhibitors used in cancer treatment can bring on a severe myositis within weeks, sometimes with heart involvement¹⁵	Tell the team about every medicine, especially any statin, since anti-HMGCR testing is part of the antibody panel; never stop a prescribed medicine on your own
Infections, as a possible trigger	A viral infection of the muscles has been suggested as a trigger, and the seasonal timing of juvenile myositis fits a role for infection, but this is not established⁵	Nothing on this page prevents it. On immune-suppressing treatment, infections need prompt attention; see When to Seek Care

Autoimmune Myositis

What Is Autoimmune Myositis?

Types & Subtypes

Polymyositis (PM)

Dermatomyositis (DM)

Inclusion Body Myositis (IBM)