Dietary Pattern and Long-Term Effects of Ambient Particulate Matter on Hypertension and Blood Pressure in Chinese Adults

Abstract

Background: Previous experimental studies have identified specific foods or nutrients that are capable of mitigating adverse health effects induced by air pollution exposure. However, whether the usual dietary pattern can modify the associations between long-term air pollution exposure, hypertension and blood pressure has not yet been assessed. \n \nMethods: This cross-sectional study included 61,081 participants aged 30-79 from baseline data of the China Multi-Ethnic Cohort (CMEC). Ambient particulate matter with aerodynamic diameters ≤1 μm, ≤2.5 μm and ≤10 μm (PM1, PM2.5, and PM10) was assessed through a satellite-based random forest approach. The associations between long-term exposure to PM and hypertension were examined by a logistic regression model, and the associations between PM and systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP) were assessed by multivariable linear regression models. The Dietary Approaches to Stop Hypertension (DASH) diet, which is a dietary pattern consisting of 7 food items, was calculated for each participant. \n \nFindings: Long-term exposure to ambient PM was associated with an increased risk of hypertension and elevated levels of SBP and PP. The DASH diet modified the associations between PM and hypertension as well as some blood pressure components, as those with a higher DASH score had significantly lower rates of PM-related high blood pressure risk (p value of interaction term < 0.05). For each 10 μg/m3 increase in PM1, PM2.5 and PM10, the participants with minimal adherence to the DASH diet had hypertension risks with ORs (95% CI) of 1.196 (1.084, 1.319), 1.145 (1.09, 1.202) and 1.080 (1.045, 1.117), whereas those with maximal adherence to the DASH diet had lower hypertension risks with ORs (95% CI) of 1.063 (0.953, 1.185), 1.074 (1.017, 1.133) and 1.038 (1.000, 1.077). For specific food items, consuming more fresh fruits, vegetables, dairy and whole grains would reduce the risk of high blood pressure caused by atmospheric particulates. \n \nInterpretation: The DASH dietary pattern reduced the hypertension risk induced by long-term exposure to ambient particulate matter. Adequate intake of foods rich in antioxidant compounds may be an effective and wide-reaching intervention to reduce the deleterious impact of air pollution on health. \n \nFunding: The National Key Research and Development Program of China (Grant No. 2017YFC0907303), the National Natural Science Foundation of China (Grant No. 81773548) and the China Postdoctoral Science Foundation (Grant No. 2020M683335). \n \nDeclaration of Interests: All authors declare no competing interests. \n \nEthics Approval Statement: Ethical approval was received from the Sichuan University Medical Ethical Review Board.