Anti-bacterial mouthwash reduces plasma nitrite following dietary nitrate supplementation but does not alter stress response

Chris Easton, Christopher Monaghan, Luke Liddle, Luke McIlvenna, Mia Burleigh, David Muggeridge, Bernadette Fernandez, Martin Feelisch

Research output: Contribution to journalMeeting Abstractpeer-review


Rinsing the mouth with anti-bacterial mouthwash (MW) suppresses the reduction of nitrate (NO3 -) to nitrite (NO2 -) and nullifies the reduction in blood pressure (BP) often reported after dietary NO3 - supplementation. Given the known interactions between the microbiome and the central nervous system, we speculated that disruption of the oral flora with MW would induce a stress response exemplified by increased BP and cortisol secretion. PURPOSE: To determine the effects of ingesting NO3 --rich beetroot juice (BR) and using MW on BP, plasma [NO2 -] and [NO3 -], and salivary [cortisol]. METHODS: After a ‘no treatment’ control (CON), ten healthy male participants rinsed with an inert placebo mouthwash (PM) prior to ingestion of 5 x 70 ml BR (~31 mmol NO3 -) over the 24 h prior to the experiment (PM+BR) followed by two further experimental arms conducted in a randomised order. In one arm, participants used MW prior to ingestion of BR (MW+BR) and in the other they used MW prior to the ingestion of a NO3 --depleted beetroot juice placebo (MW+PLA). Blood was collected and measurements performed after 30 min of laying supine. Plasma [NO2 -] and [NO3 -] were measured by chemiluminescence. RESULTS: Plasma [NO2 -] in PM+BR (209 ± 98 nM) was elevated in comparison to all other experimental arms (all P<0.04). Plasma [NO2 -] was similar between CON (95 ± 27 nM) and MW+BR (115 ± 57 nM, P=1.0) but lower in MW+PLA (41 ± 24 nM) compared to all other arms (all P<0.03). Plasma [NO3 -] was higher in PM+BR (382 ± 104 μM) and MW+BR (412 ± 87 μM) both compared separately to CON and MW+PLA (all P<0.001). Plasma [NO3 -] was not different between CON (64 ± 24 μM) and MW+PLA (43 ± 14 μM, P=0.385) or between PM+BR and MW+BR (P=1.0). Diastolic BP was lower in PM+BR (63 ± 5 mmHg) compared to MW+BR (67 ± 5 mmHg, P=0.018) but not different between other experimental arms (all P>0.43). There were no differences in systolic BP, mean arterial BP, or salivary cortisol between any arms of the experiment (all P>0.16). CONCLUSIONS: As expected, MW reduced plasma [NO2 -] but not [NO3 -], with and without ingestion of BR. Contrary to our hypothesis, however, MW did not alter BP or cortisol levels suggesting that it does not induce a stress response with short-term use. Further research employing a longer intervention and more extensive assessment of stress markers is required to confirm these observations.
Original languageEnglish
Pages (from-to)816
JournalMedicine & Science in Sports & Exercise
Issue number5S
Publication statusPublished - 1 May 2017


Dive into the research topics of 'Anti-bacterial mouthwash reduces plasma nitrite following dietary nitrate supplementation but does not alter stress response'. Together they form a unique fingerprint.

Cite this