‘Beet’ cardiovascular disease!

Posted by jchoules

2 February 2018

Green leafy vegetables, like rocket, spinach, lettuce and more commonly, beets (in the form of juice, concentrate, flapjack, or even bread!) are key elements of the Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets which are considered to be beneficial for cardiovascular health and longevity. In fact, the consumption of such vegetables, which are high in nitrate, have been shown to elevate the production of the well-known physiological signalling molecule, nitric oxide (often reported as an increase in its main biomarker, plasma nitrite) and subsequently lower systemic blood pressure, enhance cerebral and tissue blood flow, reduce the oxygen cost of submaximal exercise and improve exercise tolerance in both healthy and diseased populations.

More specifically, the reductions in blood pressure reported after inorganic nitrate consumption, in many different food forms, are comparable to those observed after antihypertensive medication, but, unlike most prescribed treatment, no adverse side-effects have been noted. Dietary nitrate has also been shown to increase the limit of tolerance during exercise tests in patients with peripheral arterial disease, heart failure, angina and when oxygen availability or the carrying-capacity of the blood is compromised, such as in hypoxia, anaemia or following blood donation. In addition, improvements in cognitive function, particularly decision making and reaction time, have been noted after nitrate ingestion.

Older individuals and those with chronic disease (including metabolic syndrome) and risk factors for atherogenesis and vascular events are likely to have lower concentrations of plasma nitrite due to an impairment in endogenously-derived nitric oxide, so too are those who smoke tobacco and use antibacterial mouthwash regularly, and, therefore, the physiological effects afforded by nitrate ingestion may be attenuated.

Sinead McDonagh

A minimum dose of 5-6 mmol of naturally derived nitrate from the diet is recommended to enhance exercise performance and mitigate complications associated with disease, such as hypertension, reduced oxygen availability or delivery and cognitive function. The additional, acute consumption of polyphenols, particularly those found in red wine, may also be helpful in augmenting nitric oxide production and the vasculature.

In summary, to optimise the therapeutic and ergogenic benefits of nitrate ingestion, the supplementation regimen must be customised; the type of supplement, dose, health status and habitual activities of the individual should be considered carefully before implementation. So why not try a green leafy salad and a glass of red wine (in moderation!) to lower your blood pressure and ‘beet’ cardiovascular disease!

http://www.bbc.co.uk/programmes/b04j9gny/episodes/guide

Sinead McDonagh, Research Fellow, Primary Care Research Group, UEMS

McDonagh STJ, Wylie LJ, Vanhatalo A, Jones AM. The effects of chronic nitrate supplementation and the use of strong and weak antibacterial agents on plasma nitrite and exercise blood pressure. International Journal of Sports Medicine 2015; 36(14):, 1177-1185.

McDonagh STJ, Vanhatalo A, Fulford J, Wylie LJ, Bailey SJ, Jones AM. (2016). Dietary nitrate supplementation attenuates the reduction in exercise tolerance following blood donation. American Journal of Physiology – Heart and Circulatory Physiology 2016; 311:H1520-H1529.

McDonagh STJ, Wylie LJ, Webster JMA, Vanhatalo A, Jones AM. Influence of dietary nitrate food forms on nitrate metabolism and blood pressure in healthy normotensive adults. Nitric Oxide 2018; 72:66-74

McDonagh STJ, Wylie LJ, Morgan PT, Vanhatalo A, Jones AM. Effects of low and high polyphenolic alcoholic beverages consumed with a nitrate-rich meal on systemic blood pressure. Original Investigation (under review).

McDonagh STJ, Vanhatalo A, Wylie LJ, Jones AM. Potential benefits of dietary nitrate ingestion in healthy and clinical populations (under review).