- A study found that nitrate-rich beetroot juice lowered blood pressure in older adults after two weeks.
- The effect appeared to be linked to changes in mouth bacteria involved in converting dietary nitrate into nitric oxide.
- Beetroot juice is not a replacement for blood pressure medication, but nitrate-rich vegetables may support heart health.
Beetroot juice may help lower blood pressure in older adults, partly by changing bacteria in the mouth.
That sounds odd, but the biology makes sense.
Beetroot is rich in nitrate, a compound also found in vegetables such as spinach, rocket, celery, fennel and kale.
Certain bacteria in the mouth help convert nitrate into compounds that support nitric oxide production.
Nitric oxide helps blood vessels relax.
That is important for healthy blood pressure control.
In the study, older and younger adults drank nitrate-rich beetroot juice twice a day for two weeks.
They also completed a separate phase with a placebo beetroot drink that had the nitrate removed.
Both age groups showed changes in their oral microbiome, but the blood pressure effect was seen in older adults.
In this group, nitrate-rich beetroot juice was linked with a fall in blood pressure.
The researchers also saw a reduction in Prevotella and an increase in bacteria such as Neisseria, which are thought to support nitrate processing.
This may help explain why older adults responded differently.
As people age, nitric oxide availability tends to decline and blood pressure often rises.
Supporting the nitrate to nitric oxide pathway may therefore matter more later in life.
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The study also raises a useful warning about antibacterial mouthwash.
If mouth bacteria are part of the nitrate pathway, wiping them out too aggressively may interfere with some of the benefits of nitrate-rich foods.
This does not mean beetroot juice is a treatment for hypertension.
People on blood pressure medication should not stop it because of a juice study.
But it does suggest nitrate-rich vegetables may be a useful part of a heart-healthy diet.
And it shows, once again, that oral health and wider health are more connected than they look.
