Efficacy of a gluten-free diet in reducing the widespread pain index and symptom severity scale in patients affected by fibromyalgia

Abstract

Objective. Dietary interventions to improve fibromyalgia (FM) symptoms reported conflicting results. This study aimed to treat FM patients with a gluten-free diet (GFD), alternated with a non-restricted gluten-containing diet, followed by a rechallenge of the GFD. Methods. Twenty postmenopausal women with FM and no history of celiac disease participated. A GFD was assigned for 6 months. This was followed by 3 months of a non-restricted gluten-containing diet and then a new GFD for another 6 months. At each visit, the widespread pain index (WPI) and the symptom severity scale (SS) scores were evaluated. Results. The mean age of the patients enrolled was 53.9±10 years. None of the patients had a diagnosis of irritable bowel disease, although they reported vague gastrointestinal symptoms. After 6 months of a GFD, a statistically significant reduction was observed for the WPI (10.3±1.8 vs 7.7±1.4; p<0.0001) and the SS scale (6.4±1.8 vs 4.15±1.6; p=0.0002). The D percentage reduction of the WPI after 6 months of GFD was -24%±9%, while for the SS scale, it was -36%±21%. The following reintroduction of a gluten-containing diet brought about a statistically significant rise in the absolute SS scale and WPI, as well as a D modification of the WPI (21%±13%) and of the SS scale (74%±90%). The rechallenge of the GFD showed a significant improvement in absolute and D WPI (-24%±7%) and SS (-36%±11%). No modifications to the body mass index were found. Conclusions. A GFD improved FM symptoms evaluated with WPI and SS. This was confirmed for the first time, also with a rechallenge of the GFD that followed a non-restricted gluten-containing diet.

Restrictive Diets in Patients with Fibromyalgia: State of the Art

“…Patients with FM consume fewer cereals than healthy controls [ 5 , 6 ], although this dietary restriction is not well supported by the inconclusive results on the effect of a GFD in published studies [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ].…”

“…Following these results obtained in mostly uncontrolled studies with very limited number of patients [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ], our group carried out a study whose objectives were to establish the prevalence of NCGS, according to the Salerno Experts’ Criteria that included a placebo-controlled gluten challenge, in a cohort of FM patients and to evaluate their clinical response to a 6 week GFD [ 18 ]. In our cohort of 142 FM patients, the prevalence of NCGS was 5.6%, similar to that estimated in the general population (0.6 to 6%), and only 21.8% responded to the GFD, mainly at the expense of an improvement in intestinal symptoms.…”

“…In summary, the studies that show symptomatic and functional improvements after following a GFD are studies with small number of patients, often with gluten-related disorders or with intraepithelial lymphocytosis, not placebo-controlled (only one controlled with another diet) and with biases such as weight loss [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ].…”

“…In FM, the low effectiveness of treatments [ 3 ], relationship with IBS [ 8 ], increased intestinal permeability [ 9 , 10 ], and previous literature on the effectiveness of restrictive diets [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ] could contribute to changing the dietary habits of patients [ 4 , 5 ] with the avoidance of food groups such as cereals or dairy products [ 5 ], which could negatively affect their physical and mental health.…”

“…In the context of the relationship between irritable bowel syndrome, or IBS, and FM [ 8 ], an increased intestinal permeability compared to healthy controls [ 9 , 10 ], and previous literature on the effectiveness of different types of restrictive diets in FM patients [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ] could also influence their modification of dietary habits and their avoidance of food groups.…”