UK researcher says chemicals in plastics can speed Alzheimer's

Researchers at the University of Kentucky are studying chemical compounds used in the production of water bottles and their link to Alzheimer's disease. (Photo by monticelllo, iStock/Getty Images Plus)

By Lindsay Travis
University of Kentucky

Researchers at the University of Kentucky are studying how elements of our natural surroundings can be potential risk factors for Alzheimer’s disease — including chemicals widely used in plastics.

“Bisphenols can accelerate Alzheimer’s disease and lead to cognitive deficits. Simply: Be smart and stay smart by avoiding plastics,” says Anika Hartz, the UK professor leading the study.

Anika Hartz, Ph.D., is the lead resarcher. (Pete Comparoni, UK) 

“Identifying environmental risk factors for Alzheimer’s is critical to mitigate cognitive decline in humans,” said Hartz, who holds positions in the College of Medicine and the College of Pharmacy. She is also affiliated with UK's Sanders-Brown Center on Aging, one of the nation’s leading centers on aging, Alzheimer’s disease and related neurodegenerative disorders. It is one of 33 National Institute on Aging-funded Alzheimer’s research centers in the U.S.

The study is funded by a grant from the National Institute of Neurological Disorders and Stroke, part of the National Institutes of Health.

Alzheimer’s is a progressive and irreversible neurological disorder. It’s estimated that 6.2 million Americans aged 65 and older are living with the disease that affects cognitive function, memory and behavior.

Hartz and her colleagues are examining three types of bisphenols, chemical compounds used in the production of polycarbonate plastics and epoxy resins. Theys are commonly found in food containers, water bottles and the lining of cans.

“Human exposure to bisphenols is inevitable due to their widespread presence in the environment,” said Hartz. “Our data show that bisphenols trigger blood-brain barrier dysfunction and memory problems, both hallmarks of Alzheimer’s, indicating that environmental bisphenols are a critical yet underrecognized risk factor for the disease.”

Hartz’s research team provided some of the first evidence that the chemicals are a clinically relevant environmental risk factor for Alzheimer’s. Bisphenols are a concern because previous research has shown they can affect the endocrine system, which regulates hormones. The brain plays a complex role in that system.

UK researchers want to better understand how the chemicals’ disruption of the endocrine system impacts the blood-brain barrier function, potentially driving cognitive decline and accelerating Alzheimer’s disease.

“The goal of this project is to develop fundamental knowledge of environmental impacts on human health that will help promote healthier lives and reduce the burden of diseases and conditions related to aging,” said Hartz. “New insights are expected from our study that will open the door for future evidence-based health management aimed at preserving cognition in health and disease.”

The work builds on preliminary data funded by a pilot grant from the UK Center for Appalachian Research in Environmental Sciences. Hartz said, “Without the pilot funding, the strong support of the UK-CARES leadership Drs. Ellen Hahn and Erin Haynes, the entire UK-CARES team, my colleagues Drs. Bjoern Bauer, Kevin Pearson, Richard Kryscio, Bernhard Hennig, Peter Nelson, Scott Stanley and the continuous support from Dr. Linda Van Eldik and the team at the Sanders-Brown Center on Aging, this would have not been possible.”

This study brings together a multidisciplinary group of researchers spanning the colleges of Medicine, Pharmacy, Public Health and Martin-Gatton College of Agriculture, Food and Environment.

Sons of smokers may be more prone to addiction-like behaviors, memory problems and anxiety, Univ. of Pennsylvania study says

The study found no effect on daughters. (iStock Photo)

If you're a parent who smokes, your sons may be more susceptible to addiction-related symptoms, memory problems and anxiety, says a new study from researchers at the University of Pennsylvania. The study is another caution about tobacco for Kentuckians, about 25 percent of whom smoke, the second highest rate in the nation.

The researchers found an association between parental tobacco use and rates of "addiction-like behaviors, cognitive impairments, and anxiety-like behaviors" in sons, a Penn news release says. The researchers did not find a similar association in daughters. The study is published in the journal Molecular Psychiatry.

Heath D. Schmidt, the paper's lead author, explains that understanding the biological effects of tobacco use is necessary understand how to children can inherent their parents' drug use. He notes that these studies' findings "highlight vulnerable populations at risk for developing nicotine dependence, cognitive impairments, and/or mental health disorders.”

Even a mild case of Covid-19 can cause long-term brain damage

Illustration from JAMA Network

Brain changes could be a lingering outcome of even mild Covid-19 cases.

Researchers at Oxford University in England reported that several months after study participants had Covid-19, they had more brain-tissue loss and more brain-size shrinkage than participants who did not have the disease. They used brain scans from the United Kingdom's Biobank—a research resource with data from half a million volunteers—that were collected from 2014 through early March 2020, and they invited hundreds of original volunteers aged 51 to 81 for a second round of scans between February and March 2021.

With nearly 800 volunteers, the new study is the largest set of Covid-19 brain-imaging analyses to date. It’s also the first to focus on patients with mostly non-severe illness and to include pre-infection data from the same people. The study is published in the peer-reviewed journal Nature.

The brain scans and cognitive scores of participants who had Covid-19 showed greater changes between the two time periods than those of the participants who did not have Covid. On average, the participants who had Covid suffered from greater tissue damage and brain shrinkage, and has less ability to do complex tasks.

The study had too few cases of influenza to draw comparisons, but brain differences among 11 volunteers who developed non–Covid-19 pneumonia between imaging sessions did not substantially overlap with brain regions implicated in the Covid-19 analysis. This could indicate that the study’s findings are specific to infection by the novel coronavirus, not respiratory infection in general.

It is unclear how long the cognitive effects of Covid-19 might last. A recent report in JAMA Neurology suggests the changes in some patients might endure, particularly for those with more severe disease. However, in a written FAQ provided to news media, the study's lead author, Gwenaëlle Douaud, suggested that the damage observed in her team’s study might improve in due course: “Since the abnormal changes we see in the brain of the infected participants might be related to their loss of smell, it is possible that recovering their smell might lead to these brain abnormalities becoming less marked over time. Similarly, it is likely that the harmful effects of the virus (whether direct, or indirect via inflammation or immune reaction) decrease over time after infection.” 

How best to manage patients’ cognitive symptoms remains an area of robust study, according to Dr. S. Andrew Josephson. The current analysis, he said, “also emphasizes just how important it is to continue to work to understand the mechanisms of these neurological symptoms and whether vaccination or severity of illness modifies them.”

Regular, moderate exercise may slow Parkinson's symptoms

Seniors exercise. (Photo by the Parkinson's Foundation)

Regular, moderate exercise one to two hours a week by people with early-stage Parkinson's disease may help slow the damage it does to the body and the mind.

A study published in Neurology, the medical journal of the American Academy of Neurology, looked at 237 people in the early stages of the disease with an average age of 63. They were followed by researchers for up to six years. Their exercise levels at the start of the study were determined by using a questionnaire that measures time and intensity of activity during the previous week: leisure activity, like walking and biking; household activity, such as gardening; and occupational activity, like taking care of others. Other tests measured verbal and memory skills and how much time it took participants to complete mental tasks.

Researchers used a common test to rate each person’s Parkinson’s symptoms on a scale of zero to four, with higher scores indicating more severe impairment. The average score of people who got less than one to two hours of moderate to vigorous exercise once or twice a week increased over six years from 1.4 to 3.7, but those who got above-average levels of moderate to vigorous exercise increased from a 1.4 to 3.0.

Similar results were seen in the cognitive tests. One cognitive test that researchers used was a common paper-and-pencil test used to measure mental processing speed. The test gives the participant 90 seconds to match numbers with geometric figures and has a maximum possible score of 110. People who got less than 15.5 hours of work per week, on average, dropped from a 44 to a 40 on the test six years later. Those with more than 15.5 hours a week dropped only one point, from 44 to 43.

“Although medications can provide people with Parkinson’s some symptom relief, they haven’t been shown to slow the progression of the disease,” said study author Kazuto Tsukita. “We found that regular physical activity, including household tasks and moderate exercise, may actually improve the course of the disease over the long run. Best of all, exercise is low cost and has few side effects.”

Researchers note that the study does not prove that maintaining an exercise program will delay the effects of Parkinson’s disease. It only shows an association.

The worse your case of Covid-19, the worse the 'brain fog' you are likely to suffer; disease has effect even in mild cases

Chart by The Economist shows levels of "brain fog" at different levels of Covid-19 seriousness.

Covid-19 is a new disease that is not fully understood, but new research by American and British scientists shows it causes problems with memory and concentration, often known as “brain fog,” even in mild cases.

The researchers teamed up with the BBC on the "Great British Intelligence Test," an online assessment billed to the public as a way to “test your cognitive strengths.” About 80,000 people "were asked to remember lists of numbers or locations on a chessboard to test their recall," The Economist reports. Other tests measured planning ability, verbal skills, problem-solving and the ability to manipulate information. "Questions about the virus, as well as about demographic factors such as age, ethnicity and socioeconomic status, were asked only after the test had ended."

The test showed that the more serious the disease, the greater the cognitive effect. "People ventilated for different respiratory diseases often face similar cognitive issues, but the performance of those with mild covid-19 symptoms suffered more than would be expected in the event of mild illness," The Economist reports. "Scientists are still unsure how exactly covid-19 is linked to cognitive impairment. . . . It remains unclear how long brain fog takes to clear, or if it does at all. That makes it difficult to estimate the lasting economic and social impact. And it reinforces worries that the health effects of Covid-19 will linger long after the pandemic is tamed."

UK College of Public Health study links diabetes to poor blood flow in the brain, but not to Alzheimer's disease

Diabetes has been linked to cerebrovascular disease, a cognitive disorder that restricts blood flow to the brain, according to a study at the University of Kentucky. Though cerebrovascular disease "is associated with stroke and ruptures that cause brain damage," the study shows that patients diagnosed with diabetes can also develop the disease.

While the study seems to settle the dispute about diabetes' linkage to the disease, researchers say it found "no significant correlation." to Alzheimer's disease, something prior research had indicated. Researchers collected samples from over 2,300 autopsied human subjects with and without diabetes.

Dr. Erin Abner, an associate professor in the UK College of Public Health, was a lead investigator in the study. Abner says the research could help prevent cerebrovascular disease in patients diagnosed with diabetes.

"While diabetes is without question both a major public health issue and a risk factor for cognitive impairment and dementia, our study suggests that cognitive dysfunction related to diabetes is likely to be preventable and underscores the idea that heart health is brain health," she said.

There is no clear answer why diabetes can cause cerebrovascular disease, but researchers "suspect this process involves many factors, including insulin resistance, hypertension and abdominal obesity," the release said.