Previous studies suggest that high serum antioxidant levels such as vitamin E could reduce the risk of hypertension(Reference Rodrigo, Prat and Passalacqua1–Reference Rumbold and Maats3). More evidence is needed to confirm the effects of dietary vitamin E on reducing blood pressure (BP), especially among adolescents. The aim of this study is to determine the relationship between dietary vitamin E intake, serum tocopherols and blood pressure in 10–19 year old UK adolescents.
585 adolescents aged 10–19 years old from the UK National Diet and Nutrition Survey (2008–2012)(4) were included in the analysis. Information was collected by interview, anthropometric data and BP were measured, and dietary data was assessed from a four-day food record. BP data was transformed to systolic BP Z-scores (SBPZ) and diastolic BP Z-scores (DBPZ). Hypertensive adolescents were defined according to the European Hypertension Society Standard(5). Univariable and multivariable linear and logistic regression was undertaken for continuous outcomes (BP values and BPZ-scores) and binary outcomes (hypertension v.s. normal BP) respectively. Confounders were selected according to a Directed Acyclic Graph and likelihood ratio tests.
Mean SBP was 112·0 ± 10·7 mmHg and mean DBP was 63·1 ± 8·5 mmHg. 7·2 % of the total sample was hypertensive. Dietary intake of vitamin E was 8·8 ± 4·2 mg/day. No significant relationship between dietary vitamin E and serum tocopherols was found. In the fully adjusted linear regression, each 1 mg increase in daily vitamin E intake was associated with 0·03 (95 % CI: −0·07 to 0·00) decrease in DBPZ (p = 0·048), and every 1 μmol/L increase in serum α-tocopherol was associated with 0·005 (95 %CI: −0·01 to −0·0001) decrease in DBPZ (p = 0·047). But no relationship was found with SBPZ or BP values. In the adjusted logistic regression, higher dietary vitamin E intake was found to reduce the risk of hypertension (OR = 0·789, 95 % IC: 0·64 to 0·96, p = 0·019). Associations between dietary vitamin E intake/serum α-tocopherol and SBPZ/DBPZ could be found in the following table.
*p < 0·05
In conclusion, higher dietary vitamin E intake and serum α-tocopherol were found to have an association with reduced DBPZ and reduced risk of hypertension in UK adolescents aged 10–19 years.