Chewing sugar gum after nitrate-rich vegetables temporarily lowers blood pressure study finds

A surprising new study from King’s College London suggests that chewing sugar-containing gum after eating nitrate-rich vegetables like beetroot, spinach, or kale may temporarily lower blood pressure by enhancing the body’s conversion of dietary nitrates into blood-vessel-relaxing compounds. The findings, published on 2 July in the *British Journal of Clinical Pharmacology*, show that sugar gum acidifies saliva, boosting nitrite levels by 45% and reducing systolic blood pressure by an average of 5 mmHg over three to six hours compared with sugar-free gum .
Researchers tracked 14 healthy volunteers who drank 70 ml of concentrated beetroot juice—naturally high in nitrates—then chewed either sugar or sugar-free gum for up to six hours. Saliva pH dropped significantly with sugar gum, accelerating the oral bacteria-mediated conversion of nitrates to nitrites. Blood nitrite concentrations rose 25%, and blood pressure fell further than with sugar-free gum. “The effect is modest and short-lived,” cautioned the study team, “and does not justify sugar gum as a hypertension treatment.” They stressed that the results merely highlight an unexpected interaction between diet and oral chemistry .
The discovery adds nuance to the established link between vegetable nitrates and cardiovascular health. For decades, clinicians have recommended nitrate-rich diets to support vascular function, but the new data suggest that everyday habits—like chewing sugar gum—can transiently amplify those benefits. “It’s a reminder that small behavioural tweaks can influence biochemical pathways we’re only beginning to understand,” said a spokesperson for the British Journal of Clinical Pharmacology .
Meanwhile, separate research published today underscores the broader risks of processed foods. A team led by Sorbonne Paris Nord University analysed data from 112,395 participants in the NutriNet-Santé cohort over nearly eight years and found that high intake of non-antioxidant preservatives—such as sorbates, nitrites, and sulfites—was associated with a 29% higher risk of developing hypertension and a 16% higher risk of overall cardiovascular disease. Even antioxidant preservatives like ascorbic acid and citric acid were linked to a 22% increased hypertension risk when consumed in large quantities .
Experts caution that the preservative study, like many in nutrition science, relies on observational data prone to confounding. “Randomised trials are needed to establish causality,” noted Anaïs Hasenböhler, lead author of the preservative analysis. The gum study, by contrast, used a controlled crossover design, lending it higher internal validity.
Taken together, the two studies illustrate the dual-edged nature of modern dietary science: one reveals an unforeseen benefit from a common habit, while the other highlights potential harms lurking in processed products. Neither offers a silver bullet for blood-pressure control, but both underscore the importance of scrutinising how everyday choices interact with the body’s biochemistry.
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