Efficacy of Arabic Coffee and Black Tea in Reducing Halitosis: A Randomized, Double-Blind, Controlled, Crossover Clinical Trial

Abstract

The aim of the study was to objectively evaluate the short-term effect of Arabic coffee and black tea on oral halitosis. This study was a single-center, randomized, double-blind, placebo-controlled, crossover clinical trial on 17 healthy individuals. During the initial visit, pre-treatment breath samples were collected from each subject and analyzed using portable gas chromatography (OralChroma™). Four interventions were evaluated, with Arabic coffee and black tea as the test intervention tools, mouthwash containing a solution (0.05% chlorhexidine, 0.05% cetylpyridinium chloride, and 0.14% zinc lactate (CHX-CPC-Zn)) as a positive control, and drinking water as a negative control. Halitosis was induced by rinsing with 10 mL solution of L-cysteine for 30 s. Twenty minutes later, a breath sample was taken to record the baseline volatile sulfur compounds (VSC) levels (T0). Then, the participants were asked to rinse with 10 mL of a randomly-assigned solution for 30 s. Sixty minutes later, another breath sample was recorded (T1). Finally, after 120 min, the final breath sample was recorded (T2). It was found that rinsing with Arabic coffee decreased the level of H₂S both in the first hour (T1) and the second hour (T2). The reduction was significantly greater at T1 (p = 0.017). There was a similar result after the volunteers rinsed with black tea. At T2, Arabic coffee showed a substantially greater reduction in H₂S (p < 0.001). On the contrary, using CHX-CPC-Zn showed a significant and continuous decrease in H₂S values in the breath throughout the experiment (p < 0.001). Water showed no significant impact on the level of VSC (p = 0.71). This study demonstrates that black tea and Arabic coffee had inhibitory effects on halitosis that was greater in the first hour and was not sustained over a long period. Additionally, Arabic coffee had a greater inhibitory effect on halitosis than black tea.

Keywords: Arabic coffee; Camellia sinensis; black tea; cardamom; cysteine challenge; oral malodor.

Figure 1

Consort flowchart of the study inclusion, allocation, and follow-up.

Figure 2

Variation in averages of H₂S for all interventions at three time intervals.

Figure 3

Variation in averages of methyl mercaptan for all interventions at three time intervals.