Staple food consumption and related selenium intake among residents in Kashin-Beck disease endemic areas of Lhasa municipality,China

Objective To assess staple food consumption patterns and daily selenium(Se) intake through staple food among residents in Kashin-Beck disease(KBD) endemic areas of Lhasa municipality and to provide evidences for KBD control and prevention in Tibet. Methods Staple food consumption frequency questionnaires were completed by 105 local residents in Lhasa KBD endemic areas and Se concentrations of 268 staple food samples were determined. The average daily Se intake through staple food among the residents was evaluated. Results Among the residents,the proportions of consuming tsamba(made of home-grown highland barley and beans) twice per day,purchased rice and flour once per day or more were 72.4%,48.6% and 66.7%,respectively. The residents in pastoral areas reported a higher proportion of consuming purchased rice frequently compared to those living in farming areas and the residents in farming-pastoral areas reported the lowest proportion; the residents aged ≤ 39 years reported a significantly higher frequency of consuming purchased rice and flour than those aged ≥ 60 years(P< 0.05). Se concentration in the rice and flour purchased in Lhasa were 36.17 μg/kg and 29.31 μg/kg,which were 3.2-4.8 times higher than that of home-grown highland barley(9.07 μg/kg),self-made tsampa(9.63 μg/kg),and home-grown wheat(7.46 μg/kg). The average daily Se intake through staple food was 8.30 μg and 76.1% of total daily Se intake was contributed to the consumption of purchased rice and flour in the residents. Conclusion The increased intake of exogenous rice and flour with high Se content has a significant effect on enhancing Se intake among local residents in Lhasa. However,the consumption amount of home-grown staple food with low Se content is still relative high,especially in farming-pastoral areas.