Does air pollution increase the risk of dementia in women?

According to a new study published online November 18, 2020, older women living in areas with high levels of air pollution have more brain contractions, as seen in Alzheimer’s disease, than women living in areas with low levels of air pollution. There is a possibility.of Neurology, American Academy of Neurology Medical Journal. The study examined particulate pollution and found that breathing high levels of this type of air pollution was associated with contraction of areas of the brain susceptible to Alzheimer’s disease.

Fine particle pollution consists of fine particles of chemicals, smoke, dust, and other pollutants floating in the air. They are less than 2.5 micrometers and are one-thirtieth the width of human hair.

“small brain Volume is a known risk factor for dementia and Alzheimer’s disease disease, But whether air pollution changes Brain structure “In our study, women in their 70s and 80s who were exposed to higher levels of air pollution had a brain associated with Alzheimer’s disease in five years,” said Dr. Diana Yunan, a research author at the University of Southern California in Los Angeles. The risk of changes in Alzheimer’s disease has increased. Our study suggests that these toxins may disrupt the structure of the brain and the connections of nerve cell networks in the brain, contributing to the progression to the disease. I will. “

The study enrolled 712 women with an average age of 78 years who did not have dementia at the start of the study. Participants provided information on race / ethnicity, education, employment, alcohol use, smoking and physical activity, as well as health history. All women underwent MRI brain scans at the beginning of the study and 5 years later.

The researchers used the address of each participant’s place of residence to determine the average exposure to air pollution for the three years prior to the first MRI scan. Then we divided the participants into four equal groups. The lowest group was exposed to an average of 7-10 micrograms of particulate contamination per cubic meter of air (μg / m).³).The best group was exposed to an average of 13 to 19 μg / m³..The US Environmental Protection Agency (EPA) considers an average annual exposure of up to 12 μg / m³ To be safe.

Researchers used machine learning tools to measure signs of Alzheimer’s disease in the brain. This tool Brain contraction Reading the brain scans of people with Alzheimer’s disease is unique to the increased risk of Alzheimer’s disease.

MRI brain scans of participants at the start of the study and five years later showed patterns of Alzheimer’s disease identified by machine learning tools, especially regional brain changes found to be vulnerable to Alzheimer’s disease. Scores were assigned based on similarity. Scores range from 0 to 1, with higher scores indicating more brain changes. Overall, women’s scores changed from 0.28 at the start of the study to 0.44 five years later.

Every 3 μg / m³ Increased air pollution exposure levels widened the range of scores between the two scans, showing an average increase of 0.03, increased brain contraction over 5 years, and increased risk of Alzheimer’s disease by 24%. It corresponds to that. The increase remained the same after adjusting for age, education, employment, cardiovascular disease, high blood pressure, physical activity, and other factors that could affect brain contraction.

“Our findings have important public health implications. Not only women exposed to high levels of air pollution, but also women exposed to air pollution levels lower than the EPA considers safe. We saw a contraction of the brain, “says Younan. “Further research is needed, but federal efforts to tighten air pollution exposure standards in the future may help reduce the risk of Alzheimer’s disease in our elderly.”

The limits of research include that it only looked at the brain Older woman, So the results may not be the same for men and below Female.. We also investigated only particulate pollution in the area, not other sources of pollution such as traffic emissions.Researchers were also unable to estimate participants’ exposure to particulates. pollution This is because national data are not available for middle-aged and young adults.

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