Associations among Antioxidant Intake and Cardiovascular Health in Women with Chronic Hypertension

Abstract

One in three American women have hypertension, a disease with modifiable risk factors. One preventative measure is a diet high in fruits and vegetables. Occurring naturally in fruits and vegetables are antioxidants vitamin C and vitamin E. We aimed to determine if higher intake of vitamin C and/or E was associated with lower blood pressure and improved vascular function, thus providing preliminary data regarding the potential effectiveness of dietary antioxidant intake on cardiovascular health among women. Using a cross-sectional design, 11 women were enrolled in the primary study. Participants completed the diet history questionnaire (DHQ), assessing nutrient intake over the previous 30 days. Blood pressure was measured based on standard procedures. Reactive hyperemic index (RHI) determined vascular dysfunction, with lower RHI indicative of worse function (EndoPAT, Itamar Medical; Israel). Descriptive statistics were used to determine sample characteristics. Association among dietary vitamin C and E intake, systolic (SBP) and diastolic (DBP) blood pressure, and RHI were examined using Pearson’s correlations (=0.05). Participants were ages 35-60, with an average BMI of 37.5 (SD=8.6). Average daily vitamin C and E intake was 95.6 mg (SD=46.2) and 12.3 IU (SD=6.6), respectively. The average SBP was 142.1 (SD=19.0) and DBP was 82.4 (SD=9.7). Average RHI was 1.57 (SD=0.5). Vitamin C and E intake were significantly positively associated with one another (r=0.7085, p=.015). However, vitamin C intake was not significantly associated with SBP (r=-0.2567, p=.446), DBP (r=0.0878, p=.797), or RHI (r= 0.2975, p=.374). Associations among vitamin E intake and SBP (r=-0.2932, p=.382), DBP (r=0.0137, p=.968), and RHI (r=0.5154, p=.105) were not statistically significant. Although it is not statistically significant, there was a trend for increased vitamin C and E intake in lowering SBP and improving vascular function. With the small sample, future studies exploring the correlation between dietary vitamin C and E intake on BP/vascular function in a larger population may identify effects of these antioxidants on cardiovascular health.