• Recent studies suggest that higher cumulative lead exposure in bones is strongly associated with increased risk of Alzheimer’s disease and other dementias.

• People with the highest bone lead levels had almost three times the risk of Alzheimer’s disease and more than twice the risk of all-cause dementia compared to those with the lowest bone lead levels.

• Current blood lead levels were not significantly associated with dementia risk, highlighting that lifetime exposures, not just recent exposures, may play an important role in later cognitive decline.

• Another recent study also shows that prenatal lead exposure may be associated with decreased cognitive performance.

dementia is a term used to describe several illnesses that affect memory, problem solving, language, and behavior. According to estimates, 57 million people There is dementia all over the world, alzheimer’s disease Contributes to 60-70% of cases.

Dementia typically occurs by Brain damage or changes. Lead is a naturally occurring toxic metal that can have negative health effects.

Exposure to lead occurs primarily through ingestion or inhalation of lead-contaminated dust, soil, paint, or water. Over time, exposure to high levels of lead can severe damage brain.

Recent research published in Alzheimer’s Disease and Dementia: Journal of the Alzheimer’s Associationsuggests that long-term exposure to lead can significantly increase the risk of Alzheimer’s disease and other forms of dementia in older adults.

Furthermore, in another study, Neurologysuggest that prenatal lead exposure may be associated with poorer thinking and memory decades later, especially for women.

Summary and key findings of the Michigan study

The study, led by researchers at the University of Michigan School of Public Health, sheds light on how historical environmental exposures, particularly from leaded gasoline, paint, and pipes, have played out previously. rules Although its use has declined dramatically, it may continue to affect the cognitive health of people born before the 1980s.

The research team analyzed data from. National Health and Nutrition Examination Survey (NHANES) It will be linked to Medicare claims and death records and will track participants for up to 30 years.

The researchers used a machine learning model to estimate lead levels in participants’ bones, which served as a biomarker of cumulative lifetime exposure.

The body stores lead in teeth and bones, and it can accumulate over time. Therefore, because blood lead concentrations reflect only recent exposures and resolve relatively quickly, they reflect a better measure of cumulative exposure.

The study found that high bone lead levels were strongly associated with increased risk of dementia. People in the highest quartile of bone lead levels had nearly three times the risk of Alzheimer’s disease compared to those in the lowest levels.

For all-cause dementia, the risk more than doubled for those with the highest cumulative lead exposure.

kelly bakulskian associate professor of epidemiology at the Michigan Department of Public Health and one of the study’s senior authors, was surprised by the magnitude of the increased risk.

“Yes, the results were quite surprising. This represents a great opportunity to help many people by reducing lead exposure levels across the population.”

In contrast, the researchers found no significant association between current blood lead levels and dementia risk, highlighting the importance of measuring long-term exposure.

Similarly, steve alderBMBS, FRCP, DM, a consultant neurologist at Cognition Health, was also surprised by the results.

“Historically, many studies of lead and cognitive decline have relied on blood lead levels, which reflect recent exposure and typically show weak associations. In contrast, bone lead represents storage over decades, and using estimates of bone lead in this study may provide a more effective picture of the true long-term burden,” Alder said.

“The finding that individuals in the top quartile of cumulative lead exposure had nearly triple the risk of Alzheimer’s disease and more than double the risk of all-cause dementia is remarkable and shocking from a public health perspective,” he added.

Other research findings related to cognitive decline

Another recent study suggests that prenatal lead exposure may be associated with poor thinking and memory decades later, especially for women.

To assess prenatal exposure, researchers analyzed baby teeth donated decades ago. From approximately 1958 to 1970, parents in the St. Louis, Missouri area donated their children’s baby teeth. radiation research. The research team tracked down the donors some 60 years later.

To date, a total of 715 people, with an average age of 62 years, have completed cognitive tests on their home computers and had their stored primary teeth analyzed.

Researchers found that higher levels of lead exposure during the second trimester of pregnancy were associated with lower scores on cognitive tests.

Specifically for female participants, each small increase in dental lead levels during the second trimester was associated with lower cognitive test scores.

Although this study does not prove that prenatal lead exposure causes cognitive decline, it does confirm a significant long-term association.

why is this important

meanwhile Public health initiatives We are working to reduce lead exposure. legacy source Contaminated soil, aging infrastructure, and older homes with lead-based paint continue to pose risks, especially in underserved communities.

Recent events, etc. flint water crisis and report lead contamination Data contained in cinnamon applesauce marketed to young children emphasizes that exposure risks still exist.

Because lead persists in the body, exposure from early childhood can cause neurodegenerative changes years later.

Bukulski said. Today’s medical news “Lead has no normal physiological function in the body, but it can hijack existing pathways. For example, it can enter cells on divalent metal transporters that normally transport iron.”

“Once inside the cell, causes general neurotoxicity by promoting oxidative stress, mitochondrial damage, and endoplasmic reticulum stress. “In animal models with a genetic susceptibility to producing amyloid and tau, exposure to lead accelerates these processes,” she explained.

talk to MNTProfessor Alder also highlighted how lead exposure can damage blood vessels and the blood-brain barrier, altering epigenetic patterns that predispose the brain to neurodegenerative changes decades later.

“These mechanisms overlap with known dementia pathways such as oxidative stress, amyloid/tau aggregation, vascular dysfunction, and epigenetic vulnerability, providing biological plausibility to epidemiological findings linking long-term lead burden and dementia,” he noted.

Nearly one in five dementia cases can be linked to lead.

Results from a University of Michigan study suggest that approximately 18% of new infections each year in the United States may be related to cumulative lead exposure.

Park Sung Kyun“We’re excited to announce that this is the first time we’ve seen this study,” said Sc.D., M.P.H., professor of epidemiology and environmental health sciences and one of the study’s senior authors. MNT:

“Although lead’s neurotoxicity is well established, previous studies lacked data to quantify lead’s impact on Alzheimer’s disease and dementia risk.”

“Using a nationally representative sample to estimate population-attributable rates, we found that for patellar lead (a bone lead marker), up to 18% of new cases of dementia each year in the United States may be associated with cumulative lead exposure. This is an alarming number.”

This may help explain part of the problem. The increasing burden of dementia In today’s elderly population.

“In the United States, if we could lower everyone’s bone lead levels to the 25th percentile, we could prevent up to 18% of future dementia cases.”
– Dr. Kelly Buculski

Additionally, results from other studies add to the evidence supporting early childhood environmental exposure. may affect Brain health decades later.

How to reduce lead exposure

These studies reinforce the need for continued efforts to eliminate remaining sources of lead exposure, especially in settings where older housing and infrastructure still expose people to this neurotoxin.

“Rather than focusing on individual interventions, the priority should be to remove residual sources of lead, such as old paint and pipes in aging infrastructure, especially in environmentally disadvantaged communities,” Park explained.

“Lead exposure is unequally distributed and addressing these disparities requires targeted policy actions and resource allocation,” he added.

“Overall, reducing environmental toxins and addressing heritage exposures through infrastructure investments and public health efforts has the potential to alleviate some of the future burden of dementia,” Alder said. MNT.

Bakulski emphasized that there is strong evidence to suggest that air pollution causes dementia and Alzheimer’s disease.

“Policies that reduce air pollution, including from motor vehicles and industrial sources, save lives and prevent dementia,” she said.

“With this new study, we are part of a growing body of research that is beginning to show that lead exposure is also likely to contribute to dementia and Alzheimer’s disease. Investments in infrastructure to reduce lead exposure will benefit public health in multiple dimensions, including the brain,” the researchers added.

of Centers for Disease Control and Prevention (CDC) Please provide the following tips to reduce lead exposure.

• If you live in a home built before 1978, have it inspected by a qualified chief inspector. When renovating an older home, use only approved methods to eliminate lead hazards.

• Check with your water provider to find out if they have a service line connected to your home. Use filter or bottled water can help To reduce exposure.

• Try to avoid products that may contain lead, such as antique toys and toy jewelry.

• Wash your hands and face regularly.

• If you work with lead, remove your shoes when you enter the house and change into clean clothes before returning home.

Dr. Bakulski emphasized that calcium’s protective role and maintaining good bone health can help reduce potential post-exposure risks.

“When we are exposed to lead, it travels through our bodies in the bloodstream. Lead has a similar size and charge to calcium, and just as our bodies take calcium from the blood and embed it in our bones, lead is stored in our bones. Activities that keep our bones strong and healthy, such as ensuring a diet with adequate calcium, can help keep old lead out of the way of our bones.”

Additionally, Alder highlighted common brain health strategies to reduce the risk of dementia.

“It remains important to adopt well-established dementia risk-reducing behaviors, including a healthy diet, regular exercise, good cardiovascular control, mental stimulation and optimizing sleep, which is supported by extensive evidence,” he concluded.

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