Drinking beetroot juice promotes the formation ofspecific oral bacteria, which are linked to healthier blood vessels and better brain function, according to a new study of people aged 70-80.
Vegetables such as beetroot, leaf lettuce, spinach and celery usually have a high content of inorganic nitrate (NO3). Many oral bacteria, on the other hand, play a role in converting nitrate into nitric oxide, which helps regulate blood vessels and neurotransmission in the brain.
Older people tend to have lower production of nitric oxide, which is associated with poorer vascular (blood vessels) and cognitive (brain) health.
In the new study from the University of Exeter, 26 healthy older people took part in two 10-day supplementation periods: one with nitrate-rich beetroot juice and one with nitrate-free placebo juice, which they drank twice daily.
The results showed higher levels of bacteria associated with good vascular and cognitive health and lower levels of bacteria associated with disease and inflammation.
Systolic blood pressure dropped an average of five points (mmHg) after they drank the beetroot juice.
“Our results suggest that adding nitrate-rich foods to the diet – in this case beetroot juice – for just ten days can significantly change the oral microbiome (composition of bacteria) for the better,” said lead author Professor Anni Vanhatalo from the University of Exeter. “Long-term maintenance of this healthy oral microbiome could slow the negative vascular and cognitive changes associated with aging,” adds the professor.
The researchers conducted tests to identify clusters of oral bacteria that thrive together under similar conditions. One cluster (Prevotella-Veillonella) that was associated with inflammation was reduced after nitrate supplementation. The team also reported a decrease in Clostridium difficile, the most common pathogen causing antibiotic-associated diarrheal diseases.
Professor Vanhatalo stressed that further research is needed to confirm the results and determine whether similar effects are found in other groups. “Our participants were healthy, active older people with generally good blood pressure,” she said. “We want to find out whether dietary nitrate can also lower blood pressure in other age groups and in people with poorer health.”
“We are working with colleagues at the University of Exeter Medical School to study the interactions between oral bacteria and cognition to better understand how diet could be used to prevent or delay cognitive deficits in old age.”
Much research has been conducted on the benefits of a healthy gut microbiome, but far less is known about the oral microbial community that plays a critical role in “activating” nitrate from a plant-rich diet.
Reference:Redox Biology (2021). “Network analysis of nitrate-sensitive oral microbiome reveals interactions with cognitive function and cardiovascular health across dietary interventions”, Anni Vanhatalo et al.
