Regular consumption of a nitrate-rich lettuce juice beverage decreases gingival inflammation in periodontal recall patients

Objectives: Dietary nitrate has been identified as an important modulator of vascular inflammation.
This two arm prospective, double-blind, placebo-controlled, randomized trial evaluated the influence of the regular consumption of a nitrate-rich lettuce juice beverage on gingival inflammation and plaque control in periodontal recall patients with Gingiva Idex (GI) as the primary and Plaque Control Record (PCR) as a secondary endpoint
Methods: A total of 44 periodontal recall patients suffering from mild to moderate gingivitis (GI > 0 ≤ 2 at a minimum of 3 teeth) were enrolled in the study. Immediately after full mouth supra- and subgingival scaling and without additional oral hygiene instructions the study participants were asked to consume 3 x daily 100 ml of a nitrate-rich lettuce juice beverage (test) or 3 x daily 100 ml of an identical, but nitrate depleted lettuce juice beverage (control) over a period of 14 days in combination with an otherwise nitrate restricted diet. The uptake of dietary nitrate in the test group was calculated to approximate 200 mg nitrate /day, slightly below the Acceptable Daily Intake (ADI) for nitrate of 3.7 mg/kg b.w./day equivalent to 222 mg nitrate per day for a 60 kg adult set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).
Results: While at baseline recorded GI mean scores did not differ significantly between the groups (GI test group: 0,57 ± 0,25; GI placebo group: 0,57 ± 0,35), at day 14 the observed mean GI score of the test group (GI: 0,26 ± 0,15) was significantly (p<0.002) lower than in the placebo group (GI: 0,47±0,23). Mean PCR scores recorded at baseline and at day 14 did not differ significantly between the groups (baseline test group: 33,0% ± 13,4; baseline placebo group: 39,0% ± 20,2; day 14 test group: 30,7% ± 14,9; day 14 placebo group 40,5% ± 19,7).
Conclusions: The level of dietary nitrate consumption in the wake of supportive periodontal therapy may be an important modulator of gingival healing.