Tuesday September 25, 2018

Youth in polluted cities at increased risk of Alzheimer’s

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Air pollution
Air pollution shortens life by more than one year in India. Wikimedia Commons
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Children and young adults living in polluted megacities are at increased risk of developing Alzheimer’s, a debilitating brain disease characterised by memory loss, a new study has warned.

“Alzheimer’s disease hallmarks start in childhood in polluted environments, and we must implement effective preventative measures early,” said one of the researchers Lilian Calderon-Garciduenas from University of Montana in the US.

Air pollution can trigger Alzheimer’s. Flickr

“It is useless to take reactive actions decades later,” Calderon-Garciduenas said. The findings, published in the Journal of Environmental Research, indicate that Alzheimer’s starts in early childhood, and the disease progression relates to age, pollution exposure and status of Apolipoprotein E (APOE 4), a well-known genetic risk factor for Alzheimer’s. The researchers studied 203 autopsies of Mexico City residents in the US ranging in age from 11 months to 40 years.

Metropolitan Mexico City is home to 24 million people exposed daily to concentrations of fine particulate matter and ozone above US Environmental Protection Agency standards. The researchers tracked two abnormal proteins that indicate development of Alzheimer’s, and they detected the early stages of the disease in babies less than a year old.

Also Read: Your daily cup of coffee can worsen Alzheimer’s symptoms

The scientists found heightened levels of the two abnormal proteins — hyperphosphorylated tau and beta amyloid — in the brains of young urbanites with lifetime exposures to fine-particulate-matter pollution (PM2.5).

They also tracked APOE 4 as well as lifetime cumulative exposure to unhealthy levels of PM2.5 — particles which are at least 30 times smaller than the diameter of a human hair and frequently cause the haze over urban areas. The researchers found hallmarks of the disease among 99.5 percent of the autopsies they examined in Mexico City. In addition, the findings showed that APOE 4 carriers had a higher risk of rapid progression of Alzheimer’s.

Alzheimer’s can cause depression too. Pixabay

The researchers believe the detrimental effects are caused by tiny pollution particles that enter the brain through the nose, lungs and gastrointestinal tract, and these particles damage all barriers and travel everywhere in the body through the circulatory system.

The authors noted that ambient air pollution is a key modifiable risk for millions of people across the globe. “Neuroprotection measures ought to start very early, including the prenatal period and childhood,” Calderon-Garciduenas said. “Defining pediatric environmental, nutritional, metabolic and genetic risk-factor interactions are key to preventing Alzheimer’s disease,” she added. IANS

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Scientists Discover A New Method To Fight Alzheimer’s, Dementia

Worldwide, about seven percent of people over 65 suffer from Alzheimer's or some form of dementia, a percentage that rises to 40 percent above the age of 85.

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Alzheimer's
One hemisphere of a healthy brain (L) is pictured next to one hemisphere of a brain of a person suffering from Alzheimer disease. VOA
Eliminating dead-but-toxic cells occurring naturally in the brains of mice designed to mimic Alzheimer’s slowed neuron damage and memory loss associated with the disease, according to a study published Wednesday that could open a new front in the fight against dementia.The accumulation in the body of “zombie cells” that can no longer divide but still cause harm to other healthy cells, a process called senescence, is common to all mammals.

Scientists have long known that these dead-beat cells gather in regions of the brain linked to old age diseases ranging from osteoarthritis and atherosclerosis to Parkinson’s and dementia.

Prior research had also shown that the elimination of senescent cells in ageing mice extended their healthy lifespan.

But the new results, published in Nature, are the first to demonstrate a cause-and-effect link with a specific disease, Alzheimer’s, the scientists said.

Alzheimer's
A lady suffering from Alzheimer’s. Flickr

But any treatments that might emerge from the research are many years down the road, they cautioned.

In experiments, a team led by Tyler Bussian of the Mayo Clinic in Rochester, Minnesota used mice genetically modified to produce the destructive, cobweb-like tangles of tau protein that form in the neurons of Alzheimer’s patients.

The mice were also programmed to allow for the elimination of “zombie” cells in the same region.

“When senescent cells were removed, we found that the diseased animals retained the ability to form memories, and eliminated signs of inflammation,” said senior author Darren Baker, also from the Mayo Clinic.

The mice likewise failed to develop Alzheimer’s signature protein “tangles”, and retained normal brain mass.

 

Alzheimer's
Alzheimer’s disease patient Isidora Tomaz, 82, sits in an armchair in her house in Lisbon, Portugal. It’s predicted that by 2050, 135 million Americans are going to suffer from mild cognitive impairment, a precursor of Alzheimer’s. VOA

Keeping zombies at bay

A closer look revealed that the “zombies” belonged to a class of cells in the brain and spinal cord, called glia, that provide crucial support and insulation to neurons.

“Preventing the build-up of senescent glia can block the cognitive decline and neuro-degeneration normally experienced by these mice,” Jay Penney and Li-Huei Tsai, both from MIT, wrote in a comment, also in Nature.

Bussian and his team duplicated the results with pharmaceuticals, suggesting that drugs could one day slow or block the emergence of Alzheimer’s by keeping these zombie cells at bay.

“There hasn’t been a new dementia drug in 15 years, so it’s exciting to see the results of this promising study in mice,” said James Pickett, head of research at Alzheimer’s Society in London.

 

Alzheimer's
The accumulation in the body of “zombie cells” that can no longer divide but still cause harm to other healthy cells, a process called senescence, is common to all mammals. IANS

For Lawrence Rajendran, deputy director of the Dementia Research Institute at King’s College London, the findings “open up new vistas for both diagnosis and therapy for neurodegenerative diseases, including Alzheimer’s.”

Up to now, dementia research has been mostly focused on the diseased neurons rather than their neighboring cells.

“It is increasingly becoming clear that other brains cells play a defining role,” Rajendran added.

Several barriers remain before the breakthrough can be translated into a “safe, effective treatment in people,” Pickett and other said.

The elderly often have lots of harmless brain cells that look like the dangerous senescent cells a drug would target, so the molecule would have to be good at telling the two apart.

Also Read: Common Painkillers Triple Harmful Side Effects in Dementia

Worldwide, about seven percent of people over 65 suffer from Alzheimer’s or some form of dementia, a percentage that rises to 40 percent above the age of 85.

The number afflicted is expected to triple by 2050 to 152 million, according to the World Health Organization, posing a huge challenge to healthcare systems. (VOA)