Effect of a Vegan Mediterranean Diet on Cardiometabolic Biomarkers, Functional Capacity, and Quality of Life in Patients with Fibromyalgia

Effect of a Vegan Mediterranean Diet on Cardiometabolic Biomarkers, Functional Capacity, and Quality of Life in Patients with Fibromyalgia

This study aims to evaluate the effect of a vegan Mediterranean diet compared to a traditional Mediterranean diet on inflammatory biomarkers, functional capacity, and quality of life in patients with fibromyalgia.

The study involves two visits to the Exercise Physiology Research Laboratory at UFV. During the first visit, participants will complete functional capacity tests, respond to questionnaires (Fibromyalgia Impact Questionnaire, Short Form-36, MDF-Fibro-17, and Tampa Scale for Kinesiophobia), and provide a blood sample from the antecubital vein collected by an auxiliary nurse from the Eurofins MEGALABS laboratory. The biochemical markers to be analyzed include: white blood cell count (neutrophils, lymphocytes, monocytes, and platelets), lipid profile, fasting blood glucose levels and acute-phase proteins (C-reactive protein). Additionally, body composition will be assessed using a Tanita TBF300, and waist circumference will be measured. Functional capacity tests will include a handgrip strength test, a 30-second chair-to-stand test, and a timed up-and-go test. Participants will undergo a six-week dietary intervention and will return for a second visit at the end of the intervention period. They will be randomly assigned to follow either a vegan Mediterranean diet or a traditional Mediterranean diet, both of which will be guided and supervised by registered dietitians. These diets will be designed to meet individual energy needs and key nutrient requirements, following the standards set by the National Academy of Medicine and the Academy of Nutrition and Dietetics. Both diets will be isocaloric and maintain an identical macronutrient distribution. After the intervention, participants will repeat the same functional tests, questionnaires, and capillary blood measurements.

Inclusion Criteria:

• Adults aged between 18 and 50 years.
• Participants with a Fibromyalgia diagnosis according to the American College of Rheumatology (ACR) criteria.
• Functional independence.
• Non-smokers.
• Low alcohol consumption (<1 serving/day).
• Pharmacological treatment stabilized for at least 4 weeks prior to the start of the study.

Exclusion Criteria:

• Pregnant, lactating, or menopausal women.
• Physical condition that prevents the performance of functional capacity tests.
• Change in pharmacological therapy during the intervention period.
• Concomitant inflammatory conditions.