Vegan versus traditional Mediterranean diet effects on cardiometabolic outcomes in women with fibromyalgia:FIBROVEG study

OBJECTIVES: Fibromyalgia (FM) is associated with adverse cardiometabolic profiles and reduced quality of life. Although plant-based dietary patterns have shown cardiovascular benefits, their effects in FM remain unclear. This randomized, parallel-arm controlled trial evaluated the effect of a vegan Mediterranean diet (VegMedDiet) compared with a traditional Mediterranean diet (MedDiet) on low-density lipoprotein cholesterol (LDL-C) and FM-related outcomes. METHODS: Twenty-two women with FM were assigned to follow either a VegMedDiet (n = 11) or a MedDiet (n = 11) for 6 weeks. Diets were isocaloric and matched for macronutrient distribution. RESULTS: The primary outcome was change in LDL-C; secondary outcomes included other cardiometabolic markers, body composition, and FM-related symptoms and were considered exploratory. Outcomes were analyzed using linear mixed-effects models accounting for repeated measures. Compared with the MedDiet, the VegMedDiet produced greater reductions in LDL-C (estimated mean difference -21.2 mg/dL; 95% CI: -38.3 to -4.08) and triglycerides (-27.4 mg/dL; 95% CI: -52.1 to -2.73). Additionally, a significantly greater reduction was observed in the FIQ pain item (estimated mean difference -1.88; 95% CI: -2.99 to -0.77; P = 0.002). CONCLUSION: These findings suggest that a VegMedDiet may contribute to short-term improvements in cardiometabolic risk markers and FM-related symptoms compared with a MedDiet, supporting its potential role as a dietary strategy in individuals with FM.