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Acute beetroot juice reduces blood pressure in young Black and White males but not females.
Grosicki, GJ, Flatt, AA, Cross, BL, Vondrasek, JD, Blumenburg, WT, Lincoln, ZR, Chall, A, Bryan, A, Patel, RP, Ricart, K, et al
Redox biology. 2023;63:102718
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Plain language summary
Cardiovascular (CV) disease is the leading cause of death in the United States. Out of all ethnic groups, CV disease is particularly common in black Americans. High blood pressure (BP) is one of the main contributors to CV disease, and black Americans exhibit a disproportionally higher incident rate of high BP when compared to other ethnic groups. Partly this is due to genetic and physiological differences, yet is also influenced by social, socioeconomic, and environmental factors. One physiological difference that may contribute to higher BP in black adults appears to be a reduced availability of nitric oxide (NO). NO is a gas that is abundant in the human body. It regulates vascular tone and elasticity of the arteries, and therefore helps to manage blood pressure. Nitrates that occur in foods can be converted to NO and thus contribute to NO levels in the body. Beetroot juice (BRJ) is rich in nitrates. This study examined whether BRJ supplementation can reduce resting BP and cardiovascular reactivity in adults. The randomized, placebo-controlled, crossover-design study was completed by 18 black and 20 white young adults, male and female, with an average age of 21. The study monitored heart rate, BP and arterial stiffness in a variety of settings. The study also assessed socioeconomic status, perceived discrimination, sleep and dietary intake. The main findings from this investigation were that despite young black adults having higher resting BP, acute BRJ supplementation reduced the pressure to a similar extent in young black and white adults, but primarily in males. This reduction correlated with increased levels of circulating nitrites. However, acute BRJ supplementation did not influence resting arterial stiffness. The result also highlighted previously seen racial differences relating to social determinants of health and lifestyle, which may contribute to the elevated BP values seen in black participants. The study demonstrated that dietary nitrate from beetroot juice has the potential to be a cost-effective blood pressure-lowering strategy for young black and white males. Yet the findings also highlighted the complex interplay of social, lifestyle, and underlying physiological factors that influence racial differences when it comes to CV health
Abstract
A complex interplay of social, lifestyle, and physiological factors contribute to Black Americans having the highest blood pressure (BP) in America. One potential contributor to Black adult's higher BP may be reduced nitric oxide (NO) bioavailability. Therefore, we sought to determine whether augmenting NO bioavailability with acute beetroot juice (BRJ) supplementation would reduce resting BP and cardiovascular reactivity in Black and White adults, but to a greater extent in Black adults. A total of 18 Black and 20 White (∼equal split by biological sex) young adults completed this randomized, placebo-controlled (nitrate (NO3-)-depleted BRJ), crossover design study. We measured heart rate, brachial and central BP, and arterial stiffness (via pulse wave velocity) at rest, during handgrip exercise, and during post-exercise circulatory occlusion. Compared with White adults, Black adults exhibited higher pre-supplementation resting brachial and central BP (Ps ≤0.035; e.g., brachial systolic BP: 116(11) vs. 121(7) mmHg, P = 0.023). Compared with placebo, BRJ (∼12.8 mmol NO3-) reduced resting brachial systolic BP similarly in Black (Δ-4±10 mmHg) and White (Δ-4±7 mmHg) adults (P = 0.029). However, BRJ supplementation reduced BP in males (Ps ≤ 0.020) but not females (Ps ≥ 0.299). Irrespective of race or sex, increases in plasma NO3- were associated with reduced brachial systolic BP (ρ = -0.237, P = 0.042). No other treatment effects were observed for BP or arterial stiffness at rest or during physical stress (i.e., reactivity); Ps ≥ 0.075. Despite young Black adults having higher resting BP, acute BRJ supplementation reduced systolic BP in young Black and White adults by a similar magnitude, an effect that was driven by males.
2.
Greater risk of severe COVID-19 in Black, Asian and Minority Ethnic populations is not explained by cardiometabolic, socioeconomic or behavioural factors, or by 25(OH)-vitamin D status: study of 1326 cases from the UK Biobank.
Raisi-Estabragh, Z, McCracken, C, Bethell, MS, Cooper, J, Cooper, C, Caulfield, MJ, Munroe, PB, Harvey, NC, Petersen, SE
Journal of public health (Oxford, England). 2020;42(3):451-460
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The coronavirus disease 2019 (COVID-19) pandemic has to date resulted in over 6 million cases. Growing reports highlight men and Black, Asian and Minority Ethnic (BAME) cohorts as at higher risk of adverse COVID-19 outcomes. The aim of this study was to investigate whether differential patterns of COVID-19 incidence and severity, by sex and ethnicity, might be explained by cardiometabolic, socio-economic, lifestyle and behavioural exposures. This study is a prospective cohort study of over half a million men and women from across the UK. Results showed that male sex, BAME ethnicity, higher body mass index and greater household size were associated with significantly greater odds of a positive result. However, the sex and ethnicity differential pattern of COVID-19 is not adequately explained by variations in cardiometabolic factors, 25(OH)-vitamin D levels, socio-economic or behavioural factors. Authors conclude that investigation of alternative biological and genetic susceptibilities as well as more comprehensive assessment of the complex economic, social and behavioural differences should be prioritised.
Abstract
BACKGROUND We examined whether the greater severity of coronavirus disease 2019 (COVID-19) amongst men and Black, Asian and Minority Ethnic (BAME) individuals is explained by cardiometabolic, socio-economic or behavioural factors. METHODS We studied 4510 UK Biobank participants tested for COVID-19 (positive, n = 1326). Multivariate logistic regression models including age, sex and ethnicity were used to test whether addition of (1) cardiometabolic factors [diabetes, hypertension, high cholesterol, prior myocardial infarction, smoking and body mass index (BMI)]; (2) 25(OH)-vitamin D; (3) poor diet; (4) Townsend deprivation score; (5) housing (home type, overcrowding) or (6) behavioural factors (sociability, risk taking) attenuated sex/ethnicity associations with COVID-19 status. RESULTS There was over-representation of men and BAME ethnicities in the COVID-19 positive group. BAME individuals had, on average, poorer cardiometabolic profile, lower 25(OH)-vitamin D, greater material deprivation, and were more likely to live in larger households and in flats/apartments. Male sex, BAME ethnicity, higher BMI, higher Townsend deprivation score and household overcrowding were independently associated with significantly greater odds of COVID-19. The pattern of association was consistent for men and women; cardiometabolic, socio-demographic and behavioural factors did not attenuate sex/ethnicity associations. CONCLUSIONS In this study, sex and ethnicity differential pattern of COVID-19 was not adequately explained by variations in cardiometabolic factors, 25(OH)-vitamin D levels or socio-economic factors. Factors which underlie ethnic differences in COVID-19 may not be easily captured, and so investigation of alternative biological and genetic susceptibilities as well as more comprehensive assessment of the complex economic, social and behavioural differences should be prioritised.