Stimulation of the nitrate-nitrite-NO-metabolism by repeated lettuce juice consumption decreases gingival inflammation in periodontal recall patients: a randomized, double-blinded, placebo-controlled clinical trial.

Aim This prospective, parallel group, two-armed, double-blind, placebo-controlled randomized trial evaluated the impact of dietary nitrate consumption on gingival inflammation in periodontal recall patients. Material and Methods Forty-four (23 test/21 placebo) periodontal recall patients with chronic gingivitis were enrolled. At baseline, gingival index (GI), plaque control record (PCR) and salivary nitrate level (SNL) were recorded, followed by sub- and supragingival debridement. Subsequently, participants were randomly provided with 100 ml bottles of a lettuce juice beverage to be consumed 3× daily over 14 days, containing either a standardized amount of nitrate resulting in an intake of approximately 200 mg nitrate per day (test) or being devoid of nitrate (placebo). Results At baseline, mean GI, PCR and SNL did not differ significantly between the groups. At day 14, mean GI of the test group was significantly reduced compared to baseline and significantly lower (p = 0.002) than in the placebo group (GI 0.3 versus 0.5). Also, mean SNL in the test group was significantly higher than in the placebo group (54.0 μg/ml versus 27.8 μg/ml; p < 0.035). Mean PCR did not change significantly in both groups. Conclusions Dietary nitrate consumption may be a useful adjunct in the control of chronic gingivitis.