New research suggests that changes in your brain function as you age may be linked to the bacteria in your mouth and on your tongue. It was found that certain bacteria is actually linked to an increased risk of Alzheimer’s disease.
The study was led by the University of Exeter, and also revealed that some bacteria found in your mouth can be associated with having better memory and attention. But how does this bacteria have an impact on your brain health?
One way that researchers found was that harmful bacteria could directly enter the bloodstream, in turn causing potential damage to the brain. Another option is that an imbalance of beneficial and harmful bacteria could reduce the conversion of nitrite in the body to nitric oxide.
This could be a cause of concern as nitric oxide is crucial to brain communication and memory formation. The study found that people who had large numbers of Neisseria and Haemophilus bacteria groups in their mouths had better attention, memory and ability to do complex tasks.
These people also had higher levels of nitrite in their mouths. Nitrite is plentiful in diets that are rich with vegetables. On the flip side, higher levels of Porphyromonas bacteria were more common in people who had memory problems, while Prevotella was more common in people who carry the Alzheimer Disease risk gene – APOE4.
This bacteria group was linked to low nitrite, which researchers believe could mean poorer brain health. Lead author Dr Joanna L’Heureux, of the University of Exeter Medical School, said: “Our findings suggest that some bacteria might be detrimental to brain health as people age.
“It raises an interesting idea for performing routine tests as part of dental checkups to measure bacterial levels and detect very early signs of declining brain health.”
While your memory and brain functions generally decline as you age, some people experience greater mental deteriorations than is expected at their age. This is called Mild Cognitive impairment, and it affects approximately 15 per cent of older adults. Sadly, these people are considered at a greater risk of developing dementia or Alzheimer’s.
The study, which was published in PNAS Nexus, involved 110 participants who were over the age of 50. These participants were all involved in an online study called PROTECT which tracks the brain health of more than 25,000 middle-aged people in the UK.
The researchers split the participants into two groups – one with no brain function decline and the other with people showing signs of Mild Cognitive Impairment. The bacteria from the participants was analysed after they sent in a mouth rinse sample.
Co-author Professor Anne Corbett, of the University of Exeter Medical School, said: “The implication of our research is profound. If certain bacteria support brain function while others contribute to decline, then treatments that alter the balance of bacteria in the mouth could be part of a solution to prevent dementia. This could be through dietary changes, probiotics, oral hygiene routines, or even targeted treatments.”