Researchers at King’s College London have discovered that chewing sugary gum after consuming nitrate-rich vegetables such as beetroot, spinach, and kale may enhance the vegetables’ blood pressure-lowering effects. The study is the first to demonstrate a link between sugary gum, increased nitrate conversion in the mouth, and reductions in blood pressure. The findings highlight the important role that oral bacteria play in transforming dietary nitrate into compounds that support cardiovascular health.
Bacteria convert nitrate absorbed by vegetables from the soil into nitrite. This compound helps relax and widen blood vessels, allowing blood to flow more easily and lowering blood pressure. Scientists have long known that this conversion process is essential for obtaining the cardiovascular benefits of nitrate-rich foods. Still, little research has examined whether changes in the oral environment can improve the efficiency of this reaction.
To investigate, researchers tested whether increasing the acidity of saliva could enhance nitrate conversion. Healthy volunteers consumed a shot of beetroot juice and were randomly assigned to chew either sugar-containing Hubba Bubba® gum or sugar-free Wrigley’s Extra® gum for three to six hours afterward. Blood and saliva samples were collected throughout the study, along with blood pressure measurements. Participants returned at least one week later to repeat the experiment using the alternative gum, allowing researchers to compare the effects directly.
The results showed that chewing sugary gum significantly increased saliva acidity, lowering oral pH by 1.4 units compared with sugar-free gum. This change was associated with a 45% increase in nitrite levels in the mouth and a 25% increase in circulating nitrite levels throughout the body. Participants who chewed sugary gum also experienced meaningful reductions in blood pressure, with systolic and diastolic blood pressure falling by nearly 3 mmHg and 2 mmHg, respectively, compared with those chewing sugar-free gum.
Dr Andrew Webb, Clinical Senior Lecturer at King’s College London, explained that understanding how saliva acidity affects nitrate conversion is important because the process influences several physiological functions, including blood pressure regulation. He noted that previous studies had suggested increased acidity might inhibit nitrate conversion, but this had never been thoroughly examined in the whole body over several hours. The new findings indicate that increased oral acidity can, under certain conditions, enhance the conversion of nitrate into biologically active nitrite and strengthen the beneficial effects of dietary nitrate.
The researchers emphasize that sugary chewing gum should not be considered a treatment for high blood pressure, as regular consumption of sugar-containing products can negatively affect dental and cardiometabolic health. Instead, the study serves as proof of concept that dietary nitrate processing can potentially be improved. Co-author Dr Charlotte Mills of the University of Reading said future research should focus on developing tooth-friendly and metabolically healthy approaches that achieve similar benefits. Because nitrate-rich foods are already widely used by athletes to support performance, the researchers plan to conduct larger studies to determine whether enhancing nitrate conversion can further improve exercise and cardiovascular outcomes.
More information: Andrew Webb et al, Lowering salivary pH with sugar-containing gum augments salivary nitrite production and blood pressure reduction with dietary nitrate (beetroot juice), British Journal of Clinical Pharmacology. DOI: 10.1002/bcp.70640
Journal information: British Journal of Clinical Pharmacology Provided by King’s College London
