Does air pollution help cause Alzheimer’s?

Elderly women living in areas plagued by air pollution may be at greater risk for getting Alzheimer’s, especially if they are genetically predisposed to the condition, according to new research from the University of Southern California.

The researchers examined female mice with the APOE4 gene, which has been shown to predispose people to cognitive decline. After being exposed to tiny air pollution particles for 15 weeks, the predisposed mice accumulated as much as 60 percent more harmful brain plaque than those in a control group of mice without the gene, according to a news release about the study.

In an earlier study, researchers linked high levels of particulate matter to decreased white and gray matter in the frontal lobe, which carries out thinking, decision-making and planning.

Overall, the studies showed that older women who live in areas with excessive fine particulate matter are 81 percent more at risk for global cognitive decline and 92 percent more likely to develop dementia, including Alzheimer’s.

“Particles generated by fossil fuels get into our body directly through the nose into the brain as well as through the lungs into our bloodstream,” said Caleb Finch, one of the authors of the new study. “Cells in the brain treat these particles as invaders and react with inflammatory responses, which over the course of time appear to exacerbate and promote Alzheimer’s disease.”

Gut bacteria may have a role in high blood pressure

A study this month in the journal Physiological Genomics found a correlation between a healthy microbiota, or community of organisms in the gut, and hypertension.

Researchers from the University of Houston, Baylor College of Medicine and the University of Texas Health Sciences Center scraped the gut microbiota from rats with high blood pressure and rats with normal blood pressure. They put each group on antibiotics, and switched their gut samples.

The group that was initially non-hypertensive quickly developed elevated blood pressure levels after receiving the gut microbiota from rats with high blood pressure. Hypertensive rats implanted with healthy microbiota saw a slight drop in blood pressure levels.

The study suggests that humans with unhealthy gut bacteria may be more likely to develop hypertension. Eating probiotic foods, trying a diversity of food types and eliminating sugar and processed foods support a healthy microbiome. The new study hints at probiotics as a potential hypertension treatment for humans, researchers said.

Poverty, crime lead to depression in elderly people

Older adults living in neighborhoods with high poverty and crime rates are more likely to become depressed, found a new study from UC Davis and the University of Minnesota.

The study, published Jan. 23 in the journal Health & Place, showed that neighborhood homicide rates accounted for almost a third of the effect of neighborhood poverty on older adult depression. Other factors included the amount of green space, social cohesion and walkability in the neighborhoods.

Using data from a three-year, New York-based study of elderly residents, researchers found that violence was the only neighborhood characteristic that substantially contributed to depression in older adults in impoverished, urban communities.

“Older adults tend to be less mobile and more dependent on the amenities, services and sources of social support in the neighborhoods where they live,” said Spruha Joshi a doctoral student in epidemiology at the University of Minnesota School of Public Health and first author on the paper. “Violence in the pathway between poverty and depression is a critical finding. Now we can look at neighborhoods that are not only poor but also have high levels of violence, and possibly provide support for older adults in the area.”

This story was originally published February 20, 2017 at 8:00 AM with the headline "Does air pollution help cause Alzheimer’s?."