Air pollutants may get to lungs and bloodstream, affecting the brain and cause cognitive decline, a UK government review suggests
Air pollution is a likely cause of dementia and overall cognitive decline in elderly people, major new research carried out on behalf of the UK government and released on Monday suggests.
The Committee on the Medical Effects of Air Pollutants (COMEAP) came to its conclusion after examining almost 70 studies in human populations, which were looking for links between air pollution and diminished mental abilities.
“It is likely that air pollution can contribute to a decline in mental ability and dementia in older people,” the report says.
Researchers believe that the most likely way this happens is through blood circulation. “It is known that air pollutants, particularly small particles, can affect the heart and blood vessels, including to the brain,” the study reads.
The evidence that links exposure to air pollutants to effects on the brain has become stronger “over the past 15 to 20 years,” the report says. Among the potential mechanisms to produce an adverse effect on brain activity is the “translocation of small particles from the lung to the blood stream and hence to the brain.”
Air pollution might also stimulate immune cells in the brain that may then damage nerve cells, although it is unclear whether it is an important factor at current pollution levels in the UK, the researchers said.
At the same time, while the research has found a link between dementia and air pollution, its authors say that they do not have enough data to say how many dementia cases are due to this cause.
The report also says that “there is evidence that air pollution… increases the risk of cardiovascular, including cerebrovascular, disease,” which is known to have an adverse effect on mental abilities.
In light of these findings, COMEAP has recommended to conduct further research to delve deeper into the issue.
According to the UK National Health Service (NHS), more than 850,000 people in Britain suffer from dementia, with elderly people the most exposed population group. It is believed that one in 14 people over the age of 65 have dementia, and the condition affects one in six people over 80.