Approximately 75 million American adults have hypertension with nearly one in every three adults experiencing a condition known as prehypertension (1). In 2013, more than 360,000 American deaths involved high blood pressure as a primary or co-morbid cause (2). In hypertensive patients, the probability of a first occurrence of heart attack and/or stroke is 70% and 80%, respectively (2). Dietary and lifestyle modifications may help some individuals maintain BP within normal ranges.

Studies of acetic acid, main component of vinegar, conducted with rat and human revealed mechanisms of potential blood pressure lowering (3-7). Also several human clinical trials to assess the efficacy of vinegar on blood pressure have previously been conducted in Japan. Kajimoto et al (2001, 2003) reported that continuous intake of 750 mg of acetic acid daily (approximately 15 mL of vinegar) reduces systolic blood pressure of adults with prehypertension as well as adults with hypertension (8-9). Sadou et al (2006) also reported similar effects with tomato vinegar in adults with prehypertension (750 mg daily acetic acid intake)(10).

The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7) published by U.S. Department of Health and Human Services in 2003 defines prehypertension as blood pressure ranging from 120-139 mmHg systolic and 80-89 mmHg diastolic (11). JNC7 states that "prehypertension is not a disease category". Individuals with prehypertension are not candidates for drug therapy, rather they are recommended to practice lifestyle modification to reduce the risk of developing hypertension in the future. The Centers for Disease Control (CDC) shows the same position to JNC7 that a person who have SBP (120-139 mmHg) or DBP (80-89 mmHg) are prehypertension at risk stage (https://www.cdc.gov/bloodpressure/measure.htm). U S Food and Drug Administration (FDA) shows similar position in 21 C.F.R. § 101.74(a)(1) that "Hypertension, or high blood pressure, generally means a systolic blood pressure of greater than 140 millimeters of mercury (mm Hg) or a diastolic blood pressure of greater than 90 mm Hg. Normotension, or normal blood pressure, is a systolic blood pressure below 140 mm Hg and diastolic blood pressure below 90 mm Hg.". Recently issued guidance by the American College of Cardiology, the American Heart Association, and other collaborators (ACC/AHA) has emphasized the importance of 10-year CVD risk in categorization of blood pressure, which is calculated using an individual's systolic and diastolic blood pressure values, blood cholesterol levels, and medical history (12). The recommended treatment for an individual with a 10-year CVD risk \<10% and blood pressure ≤139 mmHg systolic and ≤89 mmHg diastolic is lifestyle modification and not pharmacologic intervention. The target population for this study is not hypertension as defined by FDA and will align with the blood pressure category of "prehypertension" as defined by JNC7, recognized by CDC, and an additional inclusion criterion of a 10-year CVD risk \<10% in recognition of the 2017 ACC/AHA report.

Its potential effects on blood pressure of acetic acid in humans with prehypertension (all clinical trials in Japan) provide a rationale for this evaluation with a Mizkan rice vinegar fruit drink containing 750 mg acetic acid. The purpose of this trial is to investigate the effect of vinegar delivering 750 mg acetic acid on blood pressure over a 12-week period in individuals with prehypertension and a \<10% 10-year CVD risk. Additionally, the impact of 750 mg acetic acid as delivered in the vinegar drink on blood markers of the renin-angiotensin-aldosterone system and a marker of endothelial function will be assessed after 12-weeks.