Abstract

Background Childhood hypertension (CH) is related to the dietary intake and diversity of children. The study aimed to assess the critical role of dietary diversity, and seafood long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs) in reducing CH among the Iranian community. Methods A cross-sectional two-phase study with 7-12-year-old Iranian students was designed. In the initial phase, the socio-demographic characteristics, and blood pressure status (normal, pre-hypertension, and hypertension) based on systolic (SBP) and diastolic (DBP) blood pressure data were assessed. The 24-h dietary recall questionnaire was used to generate the dietary diversity score (DDS, count of consumed food groups) and dietary variety score (DVS, the cumulative number of daily consumed food items). In the second phase, the association between CH reduction and changes in serum 25-hydroxyvitamin D (25OHD), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides (TG) levels of schoolchildren intervened by a seafood diet rich in omega-3 fatty acids were assessed using the regression analyses. Results The pre-hypertension and hypertension prevalence rates were 7.8 and 9.15, respectively. CH was significantly associated with age, gender, and DDS. A significant inverse association was found between the high intake of seafood and CH (P = 0.032). The gas-chromatography analysis showed the high presence of alpha-linolenic (ALA, 6.72), eicosapentaenoic (EPA, 7.62), docosapentaenoic (DPA, 5.88), and docosahexaenoic (DHA, 18.52) acids in the seafood-based diet (p < 0.05). The low blood pressure levels with regular consumption of this healthy-functional diet were significantly associated with a reduction in BMI, LDL, TC, and TG, and a remarkable increase in 25OHD and HDL levels. The multiple linear regression showed that the SBP was highly associated with the TC (p < 0.001; beta = 0.464). Conclusions The age and DDS were efficient predictors for the different CH status. A regular seafood-rich dietary pattern due to the high LC n-3 PUFAs contents could significantly reduce the obesity-related cardiovascular risk factors.