Certain foods appear to worsen fibromyalgia pain by fueling inflammation, disrupting blood flow in the brain, or overstimulating the nervous system. People with fibromyalgia who eat diets high in refined sugars, processed foods, and unhealthy fats consistently report higher pain scores and greater disease burden compared to those who eat cleaner diets. There’s no single “fibromyalgia diet,” but the evidence points to several food categories worth reducing or cutting out entirely.
Refined Sugar and Simple Carbohydrates
Sugar may be the most impactful dietary trigger for fibromyalgia pain, and the reason goes beyond general inflammation. Fibromyalgia is a central sensitization syndrome, meaning the brain and spinal cord amplify pain signals. High sugar intake promotes insulin resistance, which causes problems in the tiny blood vessels that supply the brain. This leads to reduced blood flow in specific brain regions, and advanced imaging has confirmed these exact perfusion deficits in fibromyalgia patients. In animal studies, fructose-induced insulin resistance reproduced multiple features of neuropathic pain by altering the way nerve cells process signals.
In practical terms, this means white bread, pastries, sugary cereals, candy, soda, and other sources of rapidly absorbed sugar could be directly feeding the pain cycle. The 2025 Patient Version of Guideline for Fibromyalgia, developed from 13 international source guidelines, specifically recommends fewer refined carbohydrates as part of a balanced approach. Swapping these for complex carbohydrates like whole grains, sweet potatoes, and legumes keeps blood sugar steadier and reduces the insulin spikes that may drive central pain.
Aspartame and Artificial Sweeteners
Reaching for diet soda or sugar-free snacks as a substitute may not be the solution. Aspartame has been linked to fibromyalgia symptoms in clinical case reports where the connection was tested directly. In one case, a 50-year-old woman who had suffered widespread pain and fatigue for over a decade saw complete regression of her fibromyalgia symptoms after removing aspartame from her diet. When she reintroduced it, all symptoms returned within days. A second patient, a 43-year-old man with three years of chronic pain unresponsive to multiple treatments, also experienced complete pain resolution after eliminating aspartame.
These are individual cases, not large trials, so the effect won’t apply to everyone. But the mechanism is plausible: aspartame breaks down into compounds that can overstimulate nerve cells, a process sometimes called excitotoxicity. If you consume diet drinks, sugar-free gum, or low-calorie sweetened foods regularly, a trial period without them is a low-risk experiment worth trying.
MSG and Flavor Enhancers
Monosodium glutamate, the flavor enhancer found in many processed and restaurant foods, is already classified as a headache-causing substance in the International Classification of Headache Disorders. Its effects on fibromyalgia pain appear similar. Clinical reports have found that MSG consumption increases the frequency of fibromyalgia symptoms. In animal studies, chronic MSG intake over 21 days reduced pain thresholds by roughly 30 to 40 percent and significantly increased levels of nitric oxide in the brain, a molecule involved in pain signaling.
MSG shows up in obvious places like flavored chips, instant noodles, and fast food, but also hides in soy sauce, seasoning blends, canned soups, and frozen meals under names like “hydrolyzed protein” or “yeast extract.” Reading labels carefully is the only reliable way to reduce your exposure.
High-FODMAP Foods
FODMAPs are a group of short-chain carbohydrates that ferment in the gut and are already well known for triggering irritable bowel symptoms. Since fibromyalgia and IBS overlap frequently, researchers tested whether a low-FODMAP diet could help with pain as well. In a pilot study of fibromyalgia patients who followed a four-week low-FODMAP diet, pain scores, symptom severity, and quality of life all improved significantly.
High-FODMAP foods include onions, garlic, wheat, certain fruits (apples, pears, watermelon), dairy products containing lactose, and legumes like chickpeas and lentils. A low-FODMAP approach is not meant to be permanent. It works as a temporary elimination phase followed by gradual reintroduction to identify your specific triggers. If you have both fibromyalgia and frequent digestive symptoms like bloating, gas, or irregular bowel habits, this approach may address both problems at once.
Gluten
The relationship between gluten and fibromyalgia is real but narrower than social media suggests. In a study of 142 fibromyalgia patients, the prevalence of true non-celiac gluten sensitivity was only 5.6 percent. However, about 22 percent of participants saw improvement in intestinal symptoms on a gluten-free diet, even without a formal gluten sensitivity diagnosis.
The most detailed gluten trial tracked fibromyalgia patients through six months on a gluten-free diet, three months back on gluten, and then another six months gluten-free. After the first six months without gluten, pain scores dropped by 24 percent and symptom severity fell by 36 percent. When gluten was reintroduced, both measures climbed right back up. Removing gluten again reproduced the same improvements. This pattern suggests the effect is genuine for a subset of patients, particularly those who also experience diarrhea or signs of intestinal inflammation. A blanket gluten-free recommendation for all fibromyalgia patients isn’t supported, but if digestive symptoms are part of your picture, a structured trial is reasonable.
Histamine-Releasing Foods
Histamine intolerance occurs when your body can’t break down histamine efficiently, leading to a buildup that can cause headaches, digestive distress, and widespread discomfort. In a study of 40 fibromyalgia patients, individualized diets that eliminated histamine-triggering foods led to improvements in digestive symptoms typical of the disease. The most commonly eliminated food groups were dairy products (72.5 percent of participants), gluten-containing grains (62.5 percent), tomatoes (35 percent), garlic (22.5 percent), and oily fish (22.5 percent).
Classic high-histamine foods include aged cheeses, fermented products like sauerkraut and kimchi, cured meats, canned fish, vinegar, and alcohol, especially red wine. The triggers vary significantly from person to person, which is why testing through a histamine release assay was used in the study rather than a one-size-fits-all list. If you notice that fermented or aged foods consistently precede flares, histamine intolerance is worth investigating.
Nightshade Vegetables
Tomatoes, eggplants, peppers, and potatoes belong to the nightshade family and contain compounds called solanines. These have been shown to increase intestinal permeability and promote calcium loss from bones, which could theoretically worsen inflammatory joint and muscle symptoms. Over 10 percent of arthritis patients may react to solanine-containing plants, and some older research suggested that eliminating nightshades for four to six weeks could benefit osteoarthritis patients.
The honest picture, though, is that no randomized controlled trials have been completed on nightshade elimination for fibromyalgia or even rheumatoid arthritis. The first such trial for RA is currently being designed. Nightshades are also rich in vitamins and antioxidants, so removing them without reason means losing nutritional benefits. Unless you notice a consistent pattern of flares after eating these foods, there’s no strong basis for avoiding them preemptively.
How to Test Your Triggers
The most reliable way to identify your personal food triggers is a structured elimination diet. The typical approach involves removing suspected foods for four to six weeks, tracking your symptoms carefully, and then reintroducing one food group at a time over several days while monitoring for changes. Most fibromyalgia elimination studies use a four-week minimum for the restriction phase, though gluten trials often extend to six months before the full benefit becomes clear.
Start with the categories most supported by evidence: refined sugar, artificial sweeteners, and MSG. These carry the strongest mechanistic explanations and the lowest nutritional cost of removal. If you also have digestive symptoms, adding FODMAPs or gluten to the elimination phase makes sense. Keep a simple daily log of what you ate and how your pain, fatigue, and sleep quality were that day. Patterns often emerge within the first two to three weeks.
Removing multiple food groups simultaneously and indefinitely can lead to nutritional gaps, so the reintroduction phase matters just as much as the elimination phase. The goal is not to live on a maximally restricted diet forever. It’s to identify the specific foods that reliably make your symptoms worse, then build the most varied diet you can around those boundaries.