Effects of Dietary Nitrate on Vascular Function, Blood Pressure, the Oral Microbiome, and Biomarkers of Systemic Inflammation in Hypertensive Older Adults: a Randomized, Placebo-controlled Crossover Study

Detailed Summary

The risk for cardiovascular diseases (CVD) increases with advancing age. Developing effective lifestyle-based strategies to promote, preserve or restore cardiovascular health with aging is a high priority. The overall aim of this clinical research is to investigate the innovative concept that an increased intake of dietary nitrate (through beetroot juice) could be a feasible adjuvant therapy to treat elevated blood pressure and improve blood vessel function in older adults. Inorganic dietary nitrate, found in beetroot and green leafy vegetables, is a source of nitric oxide (NO), a signaling molecule that is important for cardiovascular health. NO is also produced in the human body, but the body's production and availability of NO decrease during ageing and CVD. The declined NO availability is associated with impaired blood vessel function, unresolved inflammatory responses, and an increased CVD risk. Dietary nitrate is an additional NO source. Following the intake of nitrate, NO is produced in a pathway that involves commensal bacteria in the mouth. So far, little is known about whether dietary nitrate improves cardiovascular health in older populations with high blood pressure. The aim of this randomized, placebo-controlled crossover study is to investigate whether the daily intake of nitrate-rich beetroot juice over four weeks translates into improved cardiovascular health-related outcomes in older adults with treated mild high blood pressure. Men and women, between the ages of 55 and 70 years, who have been diagnosed with grade 1 high blood pressure and who are taking two or more blood-pressure lowering medications will be recruited. The study will investigate whether the increased dietary nitrate intake further lowers blood pressure and improves blood vessel function. A specific aim is to examine whether the nitrate intake results in favorable changes in the oral bacteria community and the systemic inflammatory status, and whether these changes correlate with cardiovascular-related outcomes. This research will offer information on the value of dietary nitrate to counteract chronic inflammation, the latter of which plays a role in developing or worsening cardiovascular disorders, such as high blood pressure. The expected results of this study will provide important new evidence of whether nitrate-rich beetroot juice could be a key component of therapeutic interventions to improve cardiovascular health in individuals with high blood pressure.

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