| The objectives of this dissertation are to: (1) assess the validity of a food frequency questionnaire (FFQ) designed for the Health Effects of Arsenic Longitudinal Study (HEALS); (2) examine the associations between intakes of major dietary factors, dietary patterns and blood pressure in the Bangladeshi population; (3) examine the associations between arsenic exposure from drinking water and blood pressure in the Bangladeshi population; and (4) examine the interaction between arsenic exposure and nutritional factors related to arsenic metabolism on blood pressure. A validation study in a subgroup of HEALS participants was conducted to assess the validity of the FFQ in measuring long-term dietary intakes. Baseline data of the HEALS were used for cross-sectional analysis of the potential effects of arsenic exposure, nutritional factors, and their interaction on blood pressure. The results of this study suggest: (1) the validity of the FFQ designed for the HEALS in measuring long-term intakes of common foods and macronutrients was moderate; (2) the "balanced" diet, characterized by rice, some meat, small fish, fruits, and vegetables, was associated with a reduced risk of hypertension, while the "root vegetable" diet was unrelated to risk of general hypertension and the "animal protein" diet, weighted more on higher intakes of meat, milk, poultry, eggs, some bread, large fish, and fruits, was related to an increased risk of hypertension; and (3) arsenic exposure was associated with higher systolic blood pressure and wider pulse pressure, and the associations were more pronounced in those with lower intakes of Vitamin B6, B2, B12 and folate. However, we did not observe an association between arsenic exposure and risk of general hypertension. We discussed implications and directions of future research. |
