New research by a government committee has said that there is a link between air pollution and cognitive decline as well as dementia.
It is estimated that two in 10 people over the age of 65 have mild cognitive impairment. Five to 10 percent of people with it will develop dementia.
The study calls the condition : "one of the greatest, if not the greatest, global challenge for health and social care in the 21st century."
COMEAP (Committee on the Medical Effects of Air Pollutants) reviewed nearly 70 studies in human populations to see if there was a link between toxic airborne particles and cognitive decline.
The report concluded that it is likely that air pollution does contribute to decline in mental ability and dementia in older people.
It said: "The most likely way this occurs is through effects on the circulation. It is known that air pollutants, particularly small particles, can affect the heart and blood vessels, including to the brain."
The researchers found that once the particles were brain they cleared only slowly, if at all.
They also highlight that more direct damage to the brain can be caused, with the report stating: "It is also likely that some very small air pollution particles can enter the brain, and may cause direct damage."
Although they did not link the direct damage to dementia saying: "However, based on the current evidence, it does not seem likely that this is an important mechanism for the development of dementia."
Further research is still needed before recommendations are made, which is what COMEAP hopes to do as it believes more funding for research will help develop the evidence on this important topic.
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