Science

Dementia May Not Always Be the Threat It Is Now. Here’s Why.

Published

8 months ago

March 22, 2025

Dementia May Not Always Be the Threat It Is Now. Here’s Why.

Joan Presky worries about dementia. Her mother lived with Alzheimer’s disease for 14 years, the last seven in a memory-care residence, and her maternal grandfather developed dementia, too.

“I’m 100 percent convinced that this is in my future,” said Ms. Presky, 70, a retired attorney in Thornton, Colo.

Last year, she spent almost a full day with a neuropsychologist, undergoing an extensive evaluation. The results indicated that her short-term memory was fine — which she found “shocking and comforting” — and that she tested average or above in every cognitive category but one.

She’s not reassured. “I saw what Alzheimer’s was like,” she said of her mother’s long decline. “The memory of what she went through is profound for me.”

The prospect of dementia, which encompasses Alzheimer’s disease and a number of other cognitive disorders, so frightens Americans that a recent study projecting steep increases in cases over the next three decades drew enormous public attention.

The researchers’ findings, published in January in Nature Medicine, even showed up as a joke on the Weekend Update segment of “Saturday Night Live.”

“Dementia is a devastating condition, and it’s very much related to the oldest ages,” said Dr. Josef Coresh, director of the Optimal Aging Institute at NYU Langone Health and the senior author of the study. “The globe is getting older.”

Now the findings are being challenged by other dementia researchers who say that while increases are coming, they will be far smaller than Dr. Coresh and his co-authors predicted.

Using data from about 15,000 Americans over age 55, collected at four research clinics around the country from 1987 through 2020, Dr. Coresh’s team projected a lifetime dementia risk much higher than previous studies had: 42 percent, though most of that risk didn’t emerge until after age 85.

The higher lifetime number probably reflected the study’s reliance on a more diverse sample than earlier researchers had used, Dr. Coresh said, and more dementia cases identified through in-depth questionnaires, regular phone calls, medical records and death certificates.

The researchers applied their risk calculations to the U.S. population and estimated that the number of people who would develop dementia each year would roughly double, to about a million by 2060, from 514,000 in 2020.

Eric Stallard, an actuary and co-director of the Biodemography of Aging Research Unit at Duke University, read the study and thought the team “seemed very competent at their analysis” of individual risk.

But when it came to the projection that cases would double, which assumed that the incidence of dementia would remain stable over the next 40 years, “I don’t believe it,” Mr. Stallard said.

“The notion that the number of people with dementia will double over the next 25, 30 or 35 years due to the aging of baby boomers is widespread, it’s pervasive — and it’s wrong,” he added.

He and two other Duke researchers recently published a commentary in JAMA pointing out that the age-specific prevalence of dementia in this country had steadily declined for 40 years.

“If your risks are lower than your parents’ risks and this trend continues, you won’t see the doubling or tripling of dementia that’s been projected,” said Dr. Murali Doraiswamy, director of the Neurocognitive Disorders Program at Duke and a co-author of the JAMA article.

To be clear, experts agree that the number of people with dementia will climb in coming decades, simply because the disorder rises so steeply with age and the number of older adults in the United States will increase.

But Mr. Stallard estimates that the increase will be more like 10 to 25 percent by 2050. “It will still be a significant challenge for the health system in the U.S.,” he said.

The Duke group relied on its own long-term study of people over age 65, with more than 21,000 respondents in 1984 and about 16,000 in 2004, plus later data from the national Health and Retirement Study and the National Health and Aging Trends Study.

Their analysis found that among 85- to 89-year-olds, for instance, the proportion with dementia was about 23 percent in the cohort born in 1905. In those born 10 years later, the figure had dropped to about 18 percent.

By the time Americans born in 1935 reached their late 80s, about 11 percent had dementia; the projection for those born from 1945 to 1949 is now about 8 percent.

To Dr. Coresh, whose primary interest was in individual risk, the assumption that past declines would continue at about the current rate “would be great, but is quite an optimistic, dramatic decrease,” he said in an email.

Yet in another longitudinal study of older adults in England and China, published in Nature Aging last year, “we also found these quite marked improvements in more recently born cohorts,” said the lead author, Dr. John Beard, a medical epidemiologist at the Mailman School of Public Health at Columbia University.

“You would expect the increase in the absolute numbers of people with dementia in the U.S. will be less than we feared,” Dr. Beard said.

What has led to the decrease in dementia, also seen in several European countries? Often cited explanations include rising education levels, reduced smoking and improved treatment for high blood pressure and high cholesterol.

The Lancet Commission on dementia, intervention and care has developed a list of 14 modifiable risk factors, including greater use of hearing aids and reduced air pollution, that could still lead to greater declines.

Yet the reverse could also happen. If earlier and more widespread testing increases the number of dementia diagnoses, or if the definition of dementia broadens, rates will increase, Dr. Doraiswamy noted. Increasing life expectancy would have the same effect.

Obesity and diabetes, more common in recent decades, could lead to more dementia, but much-touted new drugs that reduce them could blunt that trend — if people can get them.

“None of this is inevitable,” said Dr. Gill Livingston, a psychiatrist at University College London who leads the Lancet Commission. “It depends on what we do.”

Public health policy makes a major difference, she noted, and, “The U.S. is in a time where policy is changing enormously.”

Dementia rates might rise, for example, “if people have less access to health care, so they are less likely to get their blood pressure treated and their high cholesterol treated,” Dr. Livingston said.

Slashed Medicaid coverage could lead to that result. So could a rollback of environmental policies, “if air pollution increases because of fossil fuels,” she added.

Already, dementia afflicts some American populations far more than others, researchers point out. Older women and Black people face greater risk, along with those who carry the APOE4 gene associated with Alzheimer’s disease.

Health disparities could mean that “affluent people will see lower rates of dementia” because of the new diabetes and obesity drugs, Dr. Doraiswamy said. “People who can’t afford them and whose conditions are not well-managed will see rates go up.”

The debate about how many older adults will develop dementia in coming decades, and about how individuals, families, government and the health care system should respond, will likely continue.

So will Ms. Presky’s fears.

For now, she enrolls in lifelong learning classes, takes walks and yoga classes despite orthopedic problems, listens to podcasts and reads a lot of history and fiction. She and her husband take in theater in New York and Phish concerts on the West Coast and will soon be heading to London and Paris.

Still, her advance directive contains many provisions about dementia. “I remain pessimistic,” she said, noting that her mother was diagnosed at 77. “I have seven more years before I meet her fate.”

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Science

Washington state resident dies of new H5N5 form of bird flu

Published

10 hours ago

November 22, 2025

Press Room

Washington state resident dies of new H5N5 form of bird flu

The first person infected with the H5N5 bird flu has died, according to health officials in Washington.

The person, who lived in Grays Harbor County, had been hospitalized earlier this month in Kings County, where Seattle is located.

Officials from the Washington State Department of Health did not release the person’s name, age or gender. According to a news release from Grays Harbor County health officials last week, the person was considered “older” and had underlying health conditions. Their symptoms included a high fever, confusion and trouble breathing.

The person had a backyard flock consisting of mixed domestic poultry.

Testing by the health department found virus in the “environment of the flock … making exposure to the domestic poultry, their environment, or wild birds the most likely source of exposure for this patient.”

Officials at the state’s health department said they were monitoring other people who were exposed to the flock and environment.

This particular strain of bird flu, H5N5, had never been seen in a person before. It appeared first in 2023, infecting birds and mammals in eastern Canada.

According to research published last year on the novel strain, some infected animals carried a key mutation in the virus that allows it to transfer more easily between mammals.

Epidemiologists and virologists worry that avian influenza could generate a pandemic if allowed to spread and mutate. For instance, the H5N1 virus circulating in dairy cattle in North America is one mutation away from being able to spread easily between people.

Every time a bird flu virus infects a person, concerns grow that it could change, becoming more transmissible or more deadly. For instance, if a sickened person also has another flu virus replicating in their body, there’s concern the viruses could exchange genetic material. Just by having an opportunity to replicate and evolve millions of times in the human body, it could acquire deadly mutations.

Health officials say the risk to the public remains low and that no other people involved have tested positive for avian influenza. They say there is no evidence of transmission of the virus between people, but they are monitoring anyone who was in close contact with the patient.

Science

CDC replaces website on vaccines and autism with false and misleading statements

Published

1 day ago

November 21, 2025

Press Room

CDC replaces website on vaccines and autism with false and misleading statements

The U.S. Centers for Disease Control and Prevention has altered its website on autism and vaccines, removing unequivocal statements that immunizations don’t cause the neurodevelopmental disorder and replacing them with inaccurate and misleading information about the links between the shots and autism.

Until Wednesday, the CDC page, “Autism and Vaccines,” began: “Studies have shown that there is no link between receiving vaccines and developing autism spectrum disorder (ASD).”

This was followed, in large font, by the blunt statement: “Vaccines do not cause autism.”

The rest of the page summarized some of the CDC’s own studies into autism and vaccine ingredients, none of which found any causal links between the two.

On Wednesday, the page was altered so that it now begins: “The claim ‘vaccines do not cause autism’ is not an evidence-based claim because studies have not ruled out the possibility that infant vaccines cause autism.”

The words “Vaccines do not cause autism” still appear near the top, but with an asterisk that leads to a note at the bottom.

“The header ‘Vaccines do not cause autism’ has not been removed due to an agreement with the chair of the U.S. Senate Health, Education, Labor, and Pensions Committee that it would remain on the CDC website,” the site states.

The chair of that committee, Sen. Bill Cassidy (R-La.), cast the deciding vote to advance Robert F. Kennedy Jr.’s appointment as Health and Human Services secretary, in exchange for Kennedy’s promise that he wouldn’t erode public confidence in vaccines.

“What parents need to hear right now is vaccines for measles, polio, hepatitis B and other childhood diseases are safe and effective and will not cause autism. Any statement to the contrary is wrong, irresponsible, and actively makes Americans sicker,” Cassidy said in a post on X on Thursday afternoon. “Families are getting sick and people are dying from vaccine-preventable deaths, and that tragedy needs to stop.” Cassidy’s office did not immediately respond to further requests for comment Thursday.

“Studies supporting a link have been ignored by health authorities,” HHS spokesman Andrew Dixon said in an email. “We are updating the CDC’s website to reflect gold standard, evidence-based science.”

The news was met with outrage and alarm by scientists and advocates.

“Can we trust what’s coming from CDC anymore? I don’t know the answer to that question,” said Dr. Sean O’Leary, chair of the infectious disease committee at the American Academy of Pediatrics, adding that the website change reflects a “tragic moment” for U.S. public health.

“We are appalled to find that the content on the CDC webpage ‘Autism and Vaccines’ has been changed and distorted, and is now filled with anti-vaccine rhetoric and outright lies about vaccines and autism,” the nonprofit Autism Science Foundation said in a statement. “The CDC’s previous science- and evidence-based website has been replaced with misinformation and now actually contradicts the best available science.”

Alison Singer, the organization’s co-founder and president, expressed further frustration.

“Just like we no longer study whether the Earth is flat, at some point with regard to autism and vaccines, you have to call it and say ‘enough is enough,’” Singer said. “We don’t have an unlimited amount of money with which to study autism, and if we keep asking the same questions, we will never find the true causes of autism.”

The current CDC page now says the rise in autism diagnoses correlates with an increase in the number of vaccines given to infants. Multiple researchers have argued that the rise in autism spectrum disorder diagnoses is better explained by an expanding diagnostic definition of the disorder, along with better monitoring and diagnosis for more children.

“This issue has been studied exhaustively, and it has been shown over and over again that vaccines do not cause autism,” said Colin Killick, executive director of the Autistic Self-Advocacy Network. “This administration continues to lie about autism in ways that endanger both our community and the broader population.”

Science

California regulators approve rules to curb methane leaks and prevent fires at landfills

Published

2 days ago

November 20, 2025

Press Room

California regulators approve rules to curb methane leaks and prevent fires at landfills

In one of the most important state environmental decisions this year, California air regulators adopted new rules designed to reduce methane leaks and better respond to disastrous underground fires at landfills statewide.

California Air Resources Board members voted 12-0 on Thursday to approve a batch of new regulations for the state’s nearly 200 large landfills, designed to minimize the release of methane, a powerful greenhouse gas produced by decomposing organic waste. Landfills are California’s second-largest source of methane emissions, following only the state’s large dairy cow and livestock herds.

The new requirements will force landfill operators to install additional pollution controls; more comprehensively investigate methane leaks on parts of landfills that are inaccessible with on-the-ground monitoring using new technology like drones and satellites; and fix equipment breakdowns much faster. Landfill operators also will be required to repair leaks identified through California’s new satellite-detection program.

The regulation is expected to prevent the release of 17,000 metric tons of methane annually — an amount capable of warming the atmosphere as much as 110,000 gas-fired cars driven for a year.

It also will curtail other harmful landfill pollution, such as lung-aggravating sulfur and cancer-causing benzene. Landfill operators will be required to keep better track of high temperatures and take steps to minimize the fire risks that heat could create.

There are underground fires burning in at least two landfills in Southern California — smoldering chemical reactions that are incinerating buried garbage, releasing toxic fumes and spewing liquid waste. Regulators found explosive levels of methane emanating from many other landfills across the state.

During the three-hour Air Resources Board hearing preceding the vote, several Californians who live near Chiquita Canyon Landfill — one of the known sites where garbage is burning deep underground — implored the board to act to prevent disasters in other communities across the state.

“If these rules were already updated, maybe my family wouldn’t be sick,” said Steven Howse, a 27-year resident of Val Verde. “My house wouldn’t be for sale. My close friend and neighbor would still live next door to me. And I wouldn’t be pleading with you right now. You have the power to change this.”

Landfill operators, including companies and local governments, voiced their concern about the costs and labor needed to comply with the regulation.

“We want to make sure that the rule is implementable for our communities, not unnecessarily burdensome,” said John Kennedy, a senior policy advocate for Rural County Representatives of California, a nonprofit organization representing 40 of the state’s 58 counties, many of which own and operate landfills. “While we support the overarching goals of the rule, we remain deeply concerned about specific measures including in the regulation.”

Lauren Sanchez, who was appointed chair of the California Air Resources Board in October, recently attended the United Nations’ COP30 climate conference in Brazil with Gov. Gavin Newsom. What she learned at the summit, she said, made clear to her that California’s methane emissions have international consequences, and that the state has an imperative to reduce them.

“The science is clear, acting now to reduce emissions of methane and other short-lived climate pollutants is the best way to immediately slow the pace of climate change,” Sanchez said.