Drinking beetroot juice could help lower blood pressure in older people, and new research suggests this may be because it changes the bacteria in their mouths.
This study, the largest of its kind, was carried out by scientists at the University of Exeter and published in the journal Free Radical Biology and Medicine.
The researchers looked at how older and younger adults responded to drinking beetroot juice that was high in nitrate.
Nitrate is a natural compound found in vegetables like spinach, kale, celery, and beetroot. When nitrate is converted into a substance called nitric oxide in the body, it helps keep blood vessels healthy and can lower blood pressure.
In the study, 36 older adults in their 60s and 70s and 39 younger adults under 30 took part. Each person drank either nitrate-rich beetroot juice or a placebo juice with no nitrate for two weeks.
After a break, they switched and drank the other juice for another two weeks.
The researchers collected samples of bacteria from their mouths before and after each round to see how the juice affected the microbiome — the mix of bacteria living in the mouth.
The results showed that beetroot juice changed the bacteria in everyone’s mouths, but the effect was different depending on their age. In older adults, the juice reduced the amount of potentially harmful bacteria like Prevotella, and increased the amount of helpful bacteria such as Neisseria.
This change was linked to a drop in their blood pressure after drinking the juice. This drop did not happen when they drank the placebo juice. On the other hand, the younger adults didn’t see any big changes in blood pressure.
As people age, their bodies make less nitric oxide naturally, and they are more likely to have high blood pressure. This makes it harder for their hearts to pump blood, increasing the risk of serious problems like heart attacks or strokes.
The researchers think the nitrate in beetroot juice may help by giving the body what it needs to make more nitric oxide, especially in older people.
Professor Anni Vanhatalo, one of the researchers, said that encouraging older adults to eat more nitrate-rich vegetables could be a simple way to help improve heart health. She also said that beetroot isn’t the only option—vegetables like spinach, fennel, arugula, and celery are also good sources of nitrate.
Professor Andy Jones, who also worked on the study, said the findings could lead to more research about how food affects the bacteria in our mouths and how that might reduce inflammation and improve blood pressure in aging people.
This research helps us understand how what we eat can affect our health, especially as we get older. It also shows that even small changes, like drinking beetroot juice or eating more vegetables, might have big effects on our wellbeing.
Dr. Lee Beniston from the BBSRC, which helped fund the research, said that this study shows the power of science to uncover how diet, bacteria, and aging are all connected. He hopes this kind of research can lead to better ways of staying healthy through nutrition.
The study is published in Free Radical Biology and Medicine.
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