Although hypertension is prevalent world-wide, it is an even greater problem in low- and middle-income countries, where nearly two-thirds of the hypertensive individuals reside. In Africa, 46% of adults have hypertension and it is the sixth leading cause of disability within the Sub-Saharan region. Because of the health care challenges associated with diagnosis and care in these regions, the use of a diet-based intervention may be received better than costly medications. Inorganic nitrate, a precursor to nitric oxide, and folic acid are found in relatively high levels in certain leafy green vegetables and in beetroots. Existing literature suggests the potential utility of beetroot extracts and folic acid in the control of hypertension and endothelial function. Because they partly operate through different mechanisms, it may be possible to affect an even greater control of hypertension by combining the interventions. Siervo and colleagues conducted a study to explore this hypothesis and report the results of their study in the September 2020 issue of The Journal of Nutrition.
Middle aged and older subjects (n=47) in Tanzania were enrolled in a placebo-controlled, double-blind, randomized controlled feasibility study. They were assigned to receive one of three treatments during a 60 day study. The treatments were: 1) a high-nitrate beetroot juice (~400 mg nitrate) combined with 5 mg folic acid, 2) a high-nitrate beetroot juice without folic acid; or 3) a nitrate-depleted beetroot juice. Ambulatory (24 hour) and clinically measured blood pressure determinations were made at baseline and on days 30 and 60.
Plasma and saliva samples indicated that treatment compliance was greater than 90%. Systolic blood pressure (24-hour) was reduced maximally in the high-nitrate beetroot juice only treatment, which was greater than occurred with the combined high-nitrate beetroot juice and folic acid treatment. The 24-hour diastolic pressures were only reduced by the high-nitrate beetroot juice treatment. The authors concluded that high-nitrate beetroot juice may serve as a therapy to reduce hypertension in low-income countries. They suggest longer-term studies are needed to further explore this opportunity to manage the disease in such settings.
In a commentary on this article, Hoffman articulates the need for a comprehensive approach to control hypertension in low- to middle-income countries. The much higher rate of hypertension in these countries are resulting from a myriad of factors. Because of income limitations in these regions, he notes the importance of developing and distributing interventions that are locally-acceptable forms of treatments that are also sustainable. He concludes that the approaches used by Siervo and colleagues in their study may be an effective dietary approach to reducing hypertension.
References Siervo M, Shannon O, Kandhari N, Prabhakar M, Fostier W, Köchl C, Rogathi J, Temu G, Stephan BCM, Gray WK, Haule I, Paddick S-M, Mmbaga BT, Walker R. Nitrate-rich beetroot juice reduces blood pressure in Tanzanian adults with elevated blood pressure: A double-blind randomized controlled feasibility trial. Journal of Nutrition Volume 150, Issue 9, 1 September 2020, Pages 2460–2468, https://doi.org/10.1093/jn/nxaa170.
Hoffman DJ. Use of beetroot juice extract for hypertension treatment in low- and middle-income countries. Journal of Nutrition, Volume 150, Issue 9, 1 September 2020, Pages 2233–2234, https://doi.org/10.1093/jn/nxaa215.
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