24-Hour Crisis Hotline: (877)SAFEGBC or (877)723-3422 Mental Health & Substance Abuse Issues

6502 Nursery Drive, Suite 100
Victoria, TX 77904
Fax: (361)578-5500
Regular Hours: M-Fri 8am - 5pm
Every 3rd Thurs of the Month - Extended Hours Until 7 pm

Alzheimers Disease and other Cognitive Disorders
Basic Information
Introduction & Causes of Cognitive DisordersDementiaAlzheimer's DiseaseOther Cognitive DisordersDementia Coping Skills & Behavior ManagementTraumatic Brain Injury (TBI)Conclusion and Resources
More InformationLatest News
Long-Term Outlook for Most With Serious Brain Injury Is Better Than ThoughtDrug Shows Promise in Easing Dementia-Linked PsychosisAHA News: Diabetes and Dementia Risk: Another Good Reason to Keep Blood Sugar in Check1 in 20 Cases of Dementia Occurs in People Under 65Could Menopausal Hormone Therapy Reduce Women's Odds for Dementia?Reading, Puzzles May Delay Alzheimer's by 5 Years: StudyTwo Major Health Systems Won't Administer Controversial New Alzheimer's DrugMost Marriages Survive a Spouse's Brain InjuryMedicare Mulls Coverage for Controversial Alzheimer's DrugFDA Head Asks for Investigation Into Alzheimer's Drug ApprovalNew Prescribing Instructions Tighten Use of Controversial Alzheimer's DrugMissing Teeth, Higher Odds for Dementia?AHA News: Smoking Harms the Brain, Raises Dementia Risk – But Not If You QuitHealthy Living Can Lower Your Odds for Alzheimer'sKeeping Same Nurse for All Home Health Care May Be Crucial for Dementia PatientsMost Cases of Dementia in U.S. Seniors Go Undiagnosed: StudyLilly to Seek FDA Approval for New Alzheimer's DrugCould a Type of Statin Raise Dementia Risks?Good News, Bad News From Alzheimer's Vaccine TrialPoor Sleep After Head Injury Could Point to Dementia RiskFDA Approves Alzheimer's Drug Despite Expert Panel's ObjectionsFDA Defends Approval of Controversial Alzheimer's DrugPeople of Color Have Twice the Risk of Dying After Brain Injury, Study FindsIn People With Type 1 Diabetes, Poor Blood Sugar Control Could Raise Dementia RiskThere's Been a Shift in Who's Funding Alzheimer's ResearchHealthy Living Helps Prevent Dementia, Even If It Runs in the FamilyAHA News: Is It Normal Aging or Early Signs of Dementia?Failing Kidneys Could Bring Higher Dementia RiskDementia Risk Rises as Years Lived With Type 2 Diabetes IncreasesHead Injury, Alzheimer's Appear to Affect Brain in Similar WaysBrain Injuries Raise Long-Term Risk of StrokeResearch Shows Links Between Gum Disease and Alzheimer'sAssisted Living Centers Can Do More for Dementia Patients, Experts SayDiminished Hearing, Vision Together Could Be Risk Factor for Dementia6 Steps to Reduce Caregiver StressLoneliness in Mid-Life Linked to Higher Odds for Alzheimer'sDrug Used in Cancer Patients Might Help Treat Alzheimer's'Non-Drug' Approaches Can Fight Depression in People With DementiaSuicide Attempts Spike Soon After Dementia DiagnosisCould a New Drug Help Ease Alzheimer's?AHA News: Dementia May Be a Risk Factor for Infection But Not Death From COVID-19Your Eyes May Signal Your Risk for Stroke, DementiaEven 1 Concussion May Raise Your Odds for Dementia LaterAlzheimer's Patients Are Being Given Too Many MedsMany Blacks, Hispanics Believe They'll Get Worse Care If Dementia StrikesAlzheimer's May Strike Women and Men in Different WaysHistory of Mental Illness Tied to Earlier Onset of Alzheimer's DiseaseAHA News: Black, Hispanic Families Hit Hardest by DementiaWhy Some 'Super Ager' Folks Keep Their Minds Dementia-FreeDementia Seen in Younger Adults Shows Even More Brain Damage Than Alzheimer's
Questions and AnswersLinks
Related Topics

Could Dirty Air Help Speed Alzheimer's?

HealthDay News
by By Amy Norton HealthDay Reporter
Updated: Dec 1st 2020

new article illustration

TUESDAY, Dec. 1, 2020 (HealthDay News) -- Older adults exposed to air pollution might have a heightened risk of abnormal "plaque" accumulation in the brain, a new study suggests.

Plaques refer to clumps of protein called beta-amyloid that build up in the brains of people with Alzheimer's disease. In the new study, researchers found that among older adults with memory and thinking problems, those exposed to higher levels of air pollution were more likely to show plaque buildup on brain scans.

The findings do not prove air pollution causes plaques or dementia, said lead researcher Leonardo Iaccarino, a postdoctoral fellow at the University of California, San Francisco's Memory and Aging Center.

But the results add to a body of research suggesting that air pollution is a risk factor for dementia.

A recent study, for example, found that older Americans living in polluted ZIP codes had higher odds of being hospitalized for dementia or Parkinson's disease than people breathing cleaner air.

The new study is different in that it looked at air quality and its relationship to a "biomarker" in the brain, Iaccarino said.

The 18,000 study participants all had either dementia or mild cognitive impairment (problems with memory and thinking that can progress to dementia). Each underwent a PET scan to look for beta-amyloid deposits in the brain.

Iaccarino's team used data from the U.S. Environmental Protection Agency to estimate people's exposure to air pollution -- both around the time of the PET scan and 14 years earlier, based on their ZIP codes.

Overall, 61% showed beta-amyloid clumps on their brain scans. And the odds inched up along with air pollution exposure.

People who lived in the most-polluted areas 14 years prior were 10% more likely to have evidence of plaques than those in the least-polluted areas.

Why? One question was whether heart disease or stroke could explain the connection. Air pollution can worsen those conditions, and they are linked to dementia risk.

But Iaccarino's team accounted for heart disease and stroke diagnoses, as well as respiratory and neurological conditions, smoking habits, household income and other factors. And air pollution exposure, itself, was still a predictor for having beta-amyloid plaques.

Alzheimer's researchers suspect that plaques begin to form in the brain years before dementia symptoms are apparent, Iaccarino said. So the current findings link air pollution to a brain pathology underlying the disease.

That, again, does not prove cause and effect. But based on lab research, Iaccarino said, it's possible that air pollution directly affects brain health by causing inflammation.

Xiao Wu, a researcher at Harvard University in Boston, worked on the recent study linking air pollution to hospitalizations for dementia.

He called the new findings "important," because they tie air pollution to the biology underlying Alzheimer's.

Wu agreed that it's plausible that air pollutants have a direct effect: Research suggests the microscopic inhaled particles can cross the blood-brain barrier, he noted, and possibly lead to sustained inflammation.

At this point, Wu said, research into air pollution and brain health is in early days, and much more is left to learn.

"It's very important that we look at the modifiable factors that are related to dementia and other neurological conditions," he said.

If air pollution does contribute to Alzheimer's risk, Iaccarino said, it would be just one of many factors.

"Alzheimer's is a very complex condition," he said. "Air pollution may be a small, but significant, determinant."

It's significant, in part, because air quality can be improved.

In fact, Iaccarino noted, the Lancet Commission on Dementia recently added air pollution to its list of modifiable risk factors for the disease. Others include smoking, high blood pressure, physical inactivity and traumatic brain injury.

Iaccarino also stressed that the study did not look at single air-polluting events, like wildfires, but at average, daily-life exposures to dirty air.

It all suggests that even air pollution levels within "normal" range are associated with beta-amyloid in the brain, he said.

On the positive side, Iaccarino said, Americans are living with less-polluted air, on the whole, than in years past.

"Air quality in the U.S. has improved a lot in the last 20 years," he said. "It's going in the right direction."

The findings were published online Nov. 30 in JAMA Neurology.

More information

The Alzheimer's Association has advice on keeping the brain healthy.

SOURCES: Leonardo Iaccarino, PhD, postdoctoral fellow, Memory and Aging Center, Weill Institute of Neurosciences, University of California, San Francisco; Xiao Wu, MS, PhD, researcher, biostatistics, Harvard T.H. Chan School of Public Health, Boston; JAMA Neurology, Nov. 30, 2020, online