Gastrointestinal effects of eating quinoa (Chenopodium quinoa Willd.) in celiac patients.

OBJECTIVES: Celiac disease is an enteropathy triggered by dietary gluten found in wheat, rye, and barley. Treatment involves a strict gluten-free diet (GFD). Quinoa is a highly nutritive plant from the Andes that has been recommended as part of a GFD. However, in-vitro data suggested that quinoa prolamins can stimulate innate and adaptive immune responses in celiac patients. Therefore, we aimed to evaluate the in-vivo effects of eating quinoa in adult celiac patients. METHODS: Nineteen treated celiac patients consumed 50 g of quinoa every day for 6 weeks as part of their usual GFD. We evaluated diet, serology, and gastrointestinal parameters. Furthermore, we carried out detail histological assessment of 10 patients before and after eating quinoa. RESULTS: Gastrointestinal parameters were normal. The ratio of villus height to crypt depth improved from slightly below normal values (2.8:1) to normal levels (3:1), surface-enterocyte cell height improved from 28.76 to 29.77 µm and the number of intra-epithelial lymphocytes per 100 enterocytes decreased from 30.3 to 29.7. Median values for all the blood tests remained within normal ranges, although total cholesterol (n=19) decreased from 4.6 to 4.3 mmol/l, low-density lipoprotein decreased from 2.46 to 2.45 mmol/l, high-density lipoprotein decreased from 1.8 to 1.68 mmol/l and triglycerides decreased from 0.80 to 0.79 mmol/l. CONCLUSIONS: Addition of quinoa to the GFD of celiac patients was well tolerated and did not exacerbate the condition. There was a positive trend toward improved histological and serological parameters, particularly a mild hypocholesterolemic effect. Overall, this is the first clinical data suggesting that daily 50 g of quinoa for 6 weeks can be safely tolerated by celiac patients. However, further studies are needed to determine the long-term effects of quinoa consumption.

Variable activation of immune response by quinoa (Chenopodium quinoa Willd.) prolamins in celiac disease.

BACKGROUND: Celiac disease is an enteropathy triggered by dietary gluten found in wheat, barley, and rye. The current treatment is a strict gluten-free diet. Quinoa is a highly nutritive plant from the Andes, with low concentrations of prolamins, that has been recommended as part of a gluten-free diet; however, few experimental data support this recommendation. OBJECTIVE: We aimed to determine the amount of celiac-toxic prolamin epitopes in quinoa cultivars from different regions of the Andes and the ability of these epitopes to activate immune responses in patients with celiac disease. DESIGN: The concentration of celiac-toxic epitopes was measured by using murine monoclonal antibodies against gliadin and high-molecular-weight glutenin subunits. Immune response was assessed by proliferation assays of celiac small intestinal T cells/interferon-γ (IFN-γ) and production of IFN-γ/IL-15 after organ culture of celiac duodenal biopsy samples. RESULTS: Fifteen quinoa cultivars were tested: 4 cultivars had quantifiable concentrations of celiac-toxic epitopes, but they were below the maximum permitted for a gluten-free food. Cultivars Ayacuchana and Pasankalla stimulated T cell lines at levels similar to those for gliadin and caused secretion of cytokines from cultured biopsy samples at levels comparable with those for gliadin. CONCLUSIONS: Most quinoa cultivars do not possess quantifiable amounts of celiac-toxic epitopes. However, 2 cultivars had celiac-toxic epitopes that could activate the adaptive and innate immune responses in some patients with celiac disease. These findings require further investigation in the form of in vivo studies, because quinoa is an important source of nutrients for patients with celiac disease.