Car fumes increase Alzheimer's risk in people genetically predisposed, study
Fumes are in the news after Volkswagen admitted it had faked emissions tests in a scandal that has seen the firm's share price plumment and its CEO resign. The additional pollution released may also have impacted US citizens’ health according to the EPA.
The risk posed by air pollution was further underlined by a new study in the Journal of Alzheimer’s Disease that linked exhaust fumes to higher Alzheimer’s disease risk in people with a genetic predisposition for the disease.
The authors compared the brains of people from Mexico City – where there are high levels of atmospheric particulate matter – with those of people with a similar genetic makeup who are not exposed to pollution.
Genetic predispostion
They found that when exposed to fumes people predisposed to Alzheimer’s – who have a version of the apolipoprotein E gene linked to the disease – had lower levels of N-acetylaspartate (NAA)/creatine (Cr), which is associated with healthy brain functioning.
Lead author Lilian Calderon-Garcidueňas wrote that: “APOE ε4 is likely playing a role in Mexico City children’s response to their cumulative air pollution exposures.
She added that: “Of importance for health and educational issues, Mexico City children’s detrimental hippocampal responses will likely have a negative impact on academic and social development.”
This was echoed by co-author Calderón-Garcidueňas, who said: “These results add to growing data suggesting APOE ε4 carriers could have a higher risk of developing early AD if they reside in a polluted urban environment, and unfortunately this statement applies to individuals all around the world with high exposures to air pollutants regardless of ethnicity.”
50-year window
The results are in keeping with the findings of an earlier US study which suggest that the risk of Alzheimer’s increases in response to exposure to higher levels of air pollution.
The Mexican researchers concluded that: “We have a 50-year window of opportunity between the time urban children experience the detrimental effects we are describing here and when they will present with mild cognitive impairment and dementia.
“APOE ε4, the most prevalent genetic risk factor for AD, has been understudied in children and teens. Our efforts should be aimed to identify and mitigate environmental factors influencing Alzheimer’s disease and to neuroprotect high risk children.”
Source: Journal of Alzheimer’s Disease
Title: “A Critical Proton MR Spectroscopy Marker of Alzheimer’s Disease Early Neurodegenerative Change: Low Hippocampal NAA/Cr Ratio Impacts APOEɛ4 Mexico City Children and Their Parents.”
DOI: 10.3233/JAD-150415
