Absence of an effect of high nitrate intake from beetroot juice on blood pressure in treated hypertensive individuals: a randomized controlled trial.

Randomized controlled crossover trial in 27 treated hypertensive adults taking 1 to 3 antihypertensive medications. Participants were aged 53 to 70 years, had BMI 21.0 to 34.4 kg/m2, lived in Perth, Australia, and followed a low-nitrate background diet during both intervention periods.

The active intervention was oral high-nitrate beetroot juice: 2 x 70 mL concentrated nitrate-rich beverage per day, taken with breakfast and dinner, for 1 week. The product was Beet It (James White Drinks Ltd.) and was compared with a nitrate-depleted low-nitrate placebo beetroot juice in a crossover design.

High-nitrate beetroot juice did not lower blood pressure versus the nitrate-depleted placebo after 1 week. The primary outcome, mean 24-h ambulatory blood pressure on day 7, was not significantly different, and home blood pressure also showed no significant difference. Biological exposure increased substantially, with plasma nitrite and nitrate rising 3-fold, salivary nitrite 7-fold, salivary nitrate 8-fold, and urinary nitrite and nitrate 4-fold (P < 0.001). The authors concluded that short-term high nitrate intake from beetroot juice did not reduce blood pressure in treated hypertensive individuals despite evidence of nitrate metabolism.

The intervention lasted only 1 week and included only 27 participants, limiting power and durability of inference. The crossover design and treated-hypertensive population reduce generalizability, and adverse events were not reported. Dietary nitrate restriction was instructed but not quantified with formal dietary assessment.