Doctors are studying the effects of air pollution on our brains
Unfortunately, air pollution is widespread in most western countries in today's society. It has long been clear that increased air pollution does not only cause lung diseases. Researchers have now found that air pollution can also increase the risk of dementia.
Scientists at the University of Southern California (USC) in the United States found in an investigation that air pollution can increase the risk of dementia. The doctors published the results of their study in the journal "Translational Psychiatry".
Smallest particles from the air can penetrate the brain
Air pollution is widespread in the western world. The smallest particles are released into the air by power plants and cars. These are then inhaled by people. The researchers explain that such particles can also penetrate into the brain. There they then increase the risk of dementia. Air pollution is as dangerous to the aging brain as tobacco use, says author Caleb Finch of the University of Southern California.
Doctors expose mice to air pollution
For the study, the scientists collected samples of air particles using a technology developed by university engineers. Then female mice were then exposed to air pollution.
Study examines neurodegenerative health effects
The new method makes it possible for normal air to be converted specifically into polluted air with certain impurities. The author Professor Constantinos Sioutas explains that this creates polluted air from pure air, such as on motorways or in heavily polluted cities like Beijing. "We then use such samples to test exposure and assess negative neurodevelopmental effects or neurodegenerative health effects," added the expert.
In certain laboratory mice, air pollution resulted in 60 percent more plaque
The mice carried a certain genetic variation, this is called the APOE4 gene, the researchers explain. APOE4 increases the risk of Alzheimer's. After exposure to air pollution for 15 weeks, the mice had 60 percent more so-called amyloid plaques. These accumulations of the protein are associated with the degenerative disease, the scientists explain. For their study, the researchers analyzed the data of more than 3,600 American women between the ages of 65 and 79. None of the participants had dementia at the start of the study.
Air pollution massively increases the risk of cognitive decline
Taking into account certain variables such as race, ethnicity, lifestyle and health, the researchers found that older women from areas with increased air pollution have an 81 percent higher risk of cognitive decline. Such women are also 92 percent more likely to develop signs of dementia, including Alzheimer's. The negative effects of air pollution on the brain were particularly strong among women who carried the APOE4 gene, the authors add.
Air pollution could account for about 21 percent of all dementia cases
When their results were extended to the general population, the study's authors calculated that air pollution could account for about 21 percent of all cases of dementia.
What do the microscopic particles do in the human body?
Microscopic particles are generated from fossil fuels. The particles enter our body directly through the nose and then into the brain. Cells in the brain treat these particles as intruders and react with inflammatory reactions that, over time, increase Alzheimer's and promote the disease, the scientists explain.
Air pollution damages neurons in the hippocampus in mice
The current study offers the first scientific evidence that a so-called Alzheimer's risk gene may react with particles in the air. This then leads to an accelerated aging of the brain, says author Professor Jiu-Chiuan Chen. The experimental data showed that the corresponding particles can damage neurons in the hippocampus in mice. This could make the so-called memory center more susceptible to brain aging and increase the risk of Alzheimer's, the expert added. (as)