The objective of the systematic review «Grace-Farfaglia P. Bones of contention: bone miner...»1 was to examine whether a gluten-free diet (GFD), alone or in combination with other interventions, leads to bone mineral increase or recovery in newly diagnosed adults with celiac disease (CD). The literature search was aimed at untreated and treated adults with CD observed for at least one year. The types of studies considered were cohort, case-control, and randomized controlled designs. A keyword search was accomplished in 7 databases (from January 1996 to April 2015). Literature search was aimed at studies with a focus on the treatment of newly diagnosed adults with CD that reported the dependent variable as bone mineral density (BMD) as a dual-energy X-ray absorptiometry (DXA) T-score at baseline and at the annual assessment. Treatment modalities sought included GFD, physical activity, or vitamin and mineral supplementation. Methodological quality was assessed using the STROBE criteria. After the publication year 2008, most of the publications fell into the "A" quality category.
Three categories of studies were identified: GFD; GFD and nutritional supplement; GFD and bisphosphonates; and a combination of GFD, supplement and exercise. A total of 180 articles were retrieved, and of them 20 studies fulfilled inclusion criteria. Most studies included few participants. Three were RCTs: one used GFD, another used GFD and supplements, and the third one used GFD and zoledronic acid. Studies also lacked uniformity in dietary intake and compliance assessment measures. Medical developments in diagnosis and classification of CD made study comparisons difficult because of the clinical heterogeneity between subjects with little or no villous atrophy. Therefore no meta-analysis was performed.
Among GFD studies, adherence to diet had a positive effect on bone mineral density. The greatest diet treatment gain in BMD occurred in the first year in longitudinal studies that followed individuals for more than 12 months (3 studies). Full recovery was mainly achieved after 5 years (1 study). Newly diagnosed older adults benefitted from the GFD with significant gains in femoral and lumbar spine BMD after the first year (2 studies).