Randomized trial finds chewing gum lowers blood pressure in healthy volunteers — Evidence Review
Published in British Journal of Clinical Pharmacology, by researchers from King's College London, University of Reading
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Table of Contents
Researchers at King's College London found that chewing sugary gum after eating nitrate-rich vegetables led to a temporary reduction in blood pressure, likely by enhancing the conversion of dietary nitrate to nitrite in the mouth. Most related research supports the blood-pressure-lowering effects of dietary nitrate, but the specific interaction with sugary gum is newly explored in this study (British Journal of Clinical Pharmacology).
- Several meta-analyses confirm that beetroot juice and dietary nitrate lower systolic blood pressure, and that the oral conversion of nitrate to nitrite is crucial for this effect; however, the impact of chewing gum—especially sugary gum—on this process has not been previously studied in detail 4 5 6 7 8.
- Prior studies have shown that chewing gum can influence cardiovascular parameters, sometimes raising blood pressure acutely, but the current study suggests that under specific conditions (after nitrate-rich foods and with increased mouth acidity), sugary gum can enhance blood nitrate metabolism and lower blood pressure 9 12.
- While some studies found that chewing gum could slightly increase blood pressure or heart rate, especially when compared to no chewing, the new research highlights a context-specific, short-term blood pressure reduction linked to the combination of dietary nitrate and altered oral pH from sugary gum 9 10 12.
Study Overview and Key Findings
Understanding how dietary nitrate from vegetables is converted to beneficial compounds in the body is an ongoing area of interest, given its implications for cardiovascular health. This study is notable for testing whether altering the acidity of saliva—by chewing sugary versus sugar-free gum—can enhance the conversion of dietary nitrate to nitrite, thereby amplifying its blood pressure-lowering effects. The research addresses a gap in prior studies, which have not fully examined the role of saliva pH and the impact of sugary gum on nitrate metabolism and blood pressure over several hours.
| Property | Value |
|---|---|
| Organization | King's College London, University of Reading |
| Journal Name | British Journal of Clinical Pharmacology |
| Authors | Dr. Andrew Webb, Dr. Charlotte Mills |
| Population | Healthy volunteers |
| Methods | Randomized Controlled Trial (RCT) |
| Outcome | Blood pressure, nitrite levels |
| Results | Chewing sugary gum reduced systolic BP by nearly 3 mmHg. |
Literature Review: Related Studies
To place the new findings in context, we searched the Consensus paper database, which includes more than 200 million research papers. The following search queries were used to identify relevant studies:
- bubble gum blood pressure effects
- beetroot consumption hypertension management
- systolic BP reduction chewing gum
Related Studies Table
| Topic | Key Findings |
|---|---|
| How does dietary nitrate (e.g., from beetroot) affect blood pressure? | - Inorganic nitrate and beetroot juice supplementation significantly reduce systolic blood pressure in adults, with greater effects at higher doses and longer durations 4 5 6 7 8. - Beetroot juice can lower BP in healthy individuals and in older or overweight populations, though effects are transient 6 7 8. |
| What is the effect of chewing gum (with or without sugar) on cardiovascular parameters? | - Chewing gum can acutely increase heart rate and blood pressure, especially with harder gum or during vigorous chewing 9 10. - Nicotine gum increases blood pressure in specific populations (e.g., Parkinson's patients) 11. - Chewing gum after a nitrate-rich meal can improve endothelial function but may cause a slight increase in BP 12. |
| Does gum consumption have broader cardiometabolic or vascular effects? | - Gum supplementation may help control obesity and provide potential benefits for management of cardiac disorders 1. - Some fiber-based gums (e.g., guar gum, gum arabic) may lower blood pressure or reduce postprandial hypotension, especially in older adults and those with chronic conditions 2 3. |
| How does oral nitrate-to-nitrite conversion influence blood pressure regulation? | - The oral reduction of nitrate to nitrite is essential for the blood-pressure-lowering effect of dietary nitrate; factors affecting oral microbiota or oral chemistry can modulate this process 4 5 8 12. - Chewing gum does not consistently increase nitrite conversion, but mouth acidity and oral pH may play a role 12. |
How does dietary nitrate (e.g., from beetroot) affect blood pressure?
Previous meta-analyses and clinical trials have consistently shown that dietary nitrate—mainly from beetroot juice or nitrate-rich vegetables—lowers systolic blood pressure in adults, with dose-dependent and duration-dependent effects. The findings of the new study are in agreement with this established literature, but uniquely highlight the role of oral conditions (altered by sugary gum) in maximizing this physiological benefit.
- Beetroot juice and nitrate-rich foods can reduce systolic BP by 3–7 mmHg in both healthy and at-risk populations, with effects observed within hours and lasting up to 24 hours 4 5 6 7 8.
- The hypotensive effect of dietary nitrate is mainly attributed to its oral conversion to nitrite and subsequent formation of nitric oxide, a vasodilator 4 5 8.
- Meta-analyses show greater BP reduction with higher beetroot/nitrate doses and longer supplementation periods 4 8.
- The new study adds that modulating saliva pH with sugary gum could further boost the conversion process, temporarily enhancing BP-lowering effects after a nitrate-rich meal.
What is the effect of chewing gum (with or without sugar) on cardiovascular parameters?
The cardiovascular effects of chewing gum have been mixed in prior research. While some studies report that gum chewing increases heart rate and blood pressure acutely, especially with harder gum or intense mastication, others suggest more nuanced effects depending on the context and population. The current study's finding—that sugary gum after nitrate-rich food can actually lower blood pressure—contrasts with the general trend, but is explainable by the interaction with dietary nitrate and altered oral pH.
- Chewing gum (especially hard or rigorous chewing) can raise systolic and diastolic BP by up to 14 and 11 mmHg, respectively, and increase heart rate, though these are usually transient effects 9 10.
- Nicotine gum has been shown to acutely increase BP in individuals with low baseline pressure, such as in Parkinson's disease 11.
- Chewing gum after a nitrate-rich meal improved endothelial function and slightly increased BP in one study, but did not significantly affect nitrate-to-nitrite conversion or nitric oxide levels 12.
- The present study is the first to demonstrate that under the specific condition of increased oral acidity (from sugar) after nitrate-rich food, chewing gum can enhance nitrate metabolism and lower BP.
Does gum consumption have broader cardiometabolic or vascular effects?
Beyond acute cardiovascular changes, some research suggests that regular gum consumption—especially of certain fiber-based gums—may have beneficial effects on weight management and cardiac health. These findings are tangential but relevant, as they provide context for the broader health implications of gum use.
- A meta-analysis found that gum supplementation may help control obesity (reducing BMI and waist circumference) and confer potential benefits in managing cardiac disorders 1.
- Guar gum ingestion reduced the prevalence and severity of postprandial hypotension in older adults 2.
- Gum arabic lowered systolic blood pressure in patients with chronic kidney disease, though effects on diastolic pressure were less clear 3.
- These studies suggest that the type and composition of gum (e.g., fiber content, sugar content) may influence vascular and metabolic outcomes.
How does oral nitrate-to-nitrite conversion influence blood pressure regulation?
A key mechanism underlying the antihypertensive effect of dietary nitrate is its conversion to nitrite by oral bacteria before absorption and conversion to nitric oxide in the body. This process is sensitive to oral conditions, which can be modified by food, drinks, and possibly by chewing gum.
- The efficiency of oral nitrate-to-nitrite conversion is a limiting factor for the blood pressure response to dietary nitrate 4 5 8 12.
- Factors such as mouth acidity, oral microbiota composition, and the presence of sugar or other substances can modulate this conversion 12.
- One study found that chewing gum after a nitrate-rich meal did not increase nitrite conversion, and actually led to a small increase in BP, but did improve endothelial function 12.
- The new study suggests that increasing oral acidity with sugary gum can enhance nitrite production and amplify the BP-lowering effects of dietary nitrate—an effect not consistently observed with sugar-free gum or with gum alone.
Future Research Questions
While the new findings provide intriguing insights into how oral conditions and dietary nitrate interact to influence blood pressure, several questions remain. Future research is needed to clarify the mechanisms, assess long-term effects, and explore practical applications—especially regarding athlete performance and safe, tooth-friendly interventions.
| Research Question | Relevance |
|---|---|
| What are the long-term effects of chewing sugary gum with nitrate-rich foods on blood pressure? | Current studies, including the present one, only assess acute or short-term effects; chronic impacts, safety, and sustainability need to be investigated 7 8. |
| Can tooth-friendly or sugar-free gum replicate the BP-lowering effect seen with sugary gum after nitrate-rich meals? | Sugar poses dental and metabolic risks; identifying alternatives that are equally effective would have broader clinical and public health relevance 12. |
| How does individual oral microbiome composition influence nitrate-to-nitrite conversion and BP response? | Oral bacteria mediate nitrate metabolism; variability in microbiome could explain differences in BP response to interventions 4 8 12. |
| What is the optimal timing and duration of gum chewing after nitrate-rich food consumption? | The new study tested 3–6 hours of chewing; identifying minimum effective duration and timing could improve feasibility and adherence 12. |
| Does enhancing nitrate conversion with gum chewing improve athletic performance in real-world settings? | Dietary nitrate is used by athletes for performance gains; linking oral interventions to measurable athletic outcomes would expand practical applications 4. |