Improvements may be due in part to the association between weight loss and fewer pain symptoms in patients with fibromyalgia.
Following dietary interventions may be helpful in improving symptoms of pain in patients with fibromyalgia (FMS). Specifically, plant-based diets appeared to have more consistent and overall success in symptom improvement when compared with elimination or restrictive diets, according to a study published in Nutrients.1
“Currently, exercise is the most recommended treatment method as it has been shown to reduce pain symptoms and fatigue; however, there is currently no known diet or vitamin supplementation recommended for the treatment of FMS,” investigators wrote. “Dietary interventions are a tool used for the treatment of many diseases, due to healthy diets improving physical fitness, mental health, and cognitive abilities. However, the current status of the evidence on dietary influences on FMS is not known.”
A systematic review was performed to evaluate the impact of diets for improving the pain symptoms of fibromyalgia. Investigators searched the PubMed online database in March 2022 for both intervention and observational studies, ultimately identifying 126 abstracts.
Of these, 12 studies, comprised of 546 participants, which included 11 interventions and 1 observational study, were included in the analysis. The studies took place predominantly in Spain (n = 4) and the United States (n = 3).
The dietary interventions evaluated were elimination/restrictive (n = 6), plant-based (n = 3), gluten-free (n = 2), and anti-inflammatory (n = 1). The plant-based studies were further categorized as vegetarian, raw vegetarian, and a “living food diet,” defined as an uncooked vegan diet. Elimination diets included cutting out artificial sweeteners and colors, caffeine, eggs and dairy products, and simple sugars, among others.
Pain symptoms were assessed via the visual analogue scale (VAS) for pain, tender point count (TPC), pain pressure threshold (PPT), total myalgic score (TMS), and/or the fibromyalgia impact questionnaire/revised fibromyalgia impact questionnaire (FIQ/FIQR).
Nine studies, including all plant-based diet studies, showed statistically significant effects on the measurements of pain. Patients in the vegetarian diet reported statistically significant reductions in mean VAS score from baseline compared with the end of week 6 (5.7 vs 5.0, respectively). In the living food diet, mean FIQ decreased from 51.4 at baseline to 27.6 at month 7. Mean VAS scores also significantly decreased in 3 months for patients in the vegan diet intervention cohort.
In the anti-inflammatory study, PPT measurements were linked with lower dietary inflammatory index scores. Among the elimination diets, patients who eliminated MSG and aspartame for 3 months did not show significant differences in VAS scores. However, patients who eliminated additive excitotoxins from their diet reduced tender points to less than 11 and their average FIQ, VAS, and TMS scores improved after 4 weeks. An energy-restricted diet reported significant decreases in FIQR and patients experienced more weight loss when compared with controls at month 6.
Improvements may be due in part to the association between weight loss and fewer pain symptoms in patients with FMS. Recent research also reported that patients who ate plant-based and vegetarian diets generally had a lower body weight.2
Despite these benefits, the small sample size and short intervention periods made it difficult for investigators to recommend any specific diets for this patient population.
“Further studies should be conducted for all 4 diet categories included in this review and be completed with larger sample sizes and longer intervention periods,” investigators concluded. “Furthermore, using dietary intervention implementation strategies to enhance participants’ adherence to the diet regimen, and including body weight and biomarker measurements to explore potential biological mechanisms are other ways to advance research.”