Health

Some Alzheimer's cases may be caused by copies of a single gene, research shows

Published

2 years ago

May 7, 2024

Some Alzheimer's cases may be caused by copies of a single gene, research shows

Researchers have identified a genetic form of late-in-life Alzheimer’s disease for the first time, which occurs in people inheriting two copies of the APOE4 gene.
APOE4 is known to increase the risk of Alzheimer’s.
Symptoms in those with two APOE4 copies can manifest seven to ten years earlier compared to those with other risk factors.

For the first time, researchers have identified a genetic form of late-in-life Alzheimer’s disease — in people who inherit two copies of a worrisome gene.

Scientists have long known a gene called APOE4 is one of many things that can increase people’s risk for Alzheimer’s, including simply getting older. The vast majority of Alzheimer’s cases occur after age 65. But research published Monday suggests that for people who carry not one but two copies of the gene, it’s more than a risk factor, it’s an underlying cause of the mind-robbing disease.

The findings mark a distinction with “profound implications,” said Dr. Juan Fortea, who led the study the Sant Pau Research Institute in Barcelona, Spain.

CAN WE REVERSE ALZHEIMER’S DISEASE? EXPERTS SUGGEST ‘NEW PARADIGM’ FOR COMBATING DEMENTIA

Among them: Symptoms can begin seven to 10 years sooner than in other older adults who develop Alzheimer’s.

For the first time, researchers have identified a genetic form of late-in-life Alzheimer’s disease — in people who inherit two copies of a worrisome gene. (AP Photo/David Duprey, File)

An estimated 15% of Alzheimer’s patients carry two copies of APOE4, meaning those cases “can be tracked back to a cause and the cause is in the genes,” Fortea said. Until now, genetic forms of Alzheimer’s were thought to be only types that strike at much younger ages and account for less than 1% of all cases.

Scientists say the research makes it critical to develop treatments that target the APOE4 gene. Some doctors won’t offer the only drug that has been shown to modestly slow the disease, Leqembi, to people with the gene pair because they’re especially prone to a dangerous side effect, said Dr. Reisa Sperling, a study coauthor at Harvard-affiliated Brigham and Women’s Hospital in Boston.

Sperling hunts ways to prevent or at least delay Alzheimer’s and “this data for me says wow, what an important group to be able to go after before they become symptomatic.”

But the news doesn’t mean people should race for a gene test. “It’s important not to scare everyone who has a family history” of Alzheimer’s because this gene duo isn’t behind most cases, she told The Associated Press.

HOW DO GENETICS AFFECT ALZHEIMER’S?

More than 6 million Americans, and millions more worldwide, have Alzheimer’s. A handful of genes are known to cause rare “early-onset” forms, mutations passed through families that trigger symptoms unusually young, by age 50. Some cases also are linked to Down syndrome.

But Alzheimer’s most commonly strikes after 65, especially in the late 70s to 80s, and the APOE gene – which also affects how the body handles fats — was long known to play some role. There are three main varieties. Most people carry the APOE3 variant that appears to neither increase nor decrease Alzheimer’s risk. Some carry APOE2, which provides some protection against Alzheimer’s.

APOE4 has long been labeled the biggest genetic risk factor for late-in-life Alzheimer’s, with two copies risker than one. About 2% of the global population is estimated to have inherited a copy from each parent.

RESEARCH POINTS TO A CAUSE FOR A SUBSET OF ALZHEIMER’S

To better understand the gene’s role, Fortea’s team used data from 3,297 brains donated for research and from over 10,000 people in U.S. and European Alzheimer’s studies. They examined symptoms and early hallmarks of Alzheimer’s such as sticky amyloid in the brain.

People with two APOE4 copies were accumulating more amyloid at age 55 than those with just one copy or the “neutral” APOE3 gene variety, they reported in the journal Nature Medicine. By age 65, brain scans showed significant plaque buildup in nearly three-quarters of those double carriers – who also were more likely to have initial Alzheimer’s symptoms around that age rather than in the 70s or 80s.

Fortea said the disease’s underlying biology was remarkably similar to young inherited types.

It appears more like “a familial form of Alzheimer’s,” said Dr. Eliezer Masliah of the National Institute on Aging. “It is not just a risk factor.”

Importantly, not everyone with two APOE4 genes develops Alzheimer’s symptoms and researchers need to learn why, Sperling cautioned.

“It’s not quite destiny,” she said.

HOW THE NEW FINDINGS MAY AFFECT ALZHEIMER’S RESEARCH AND TREATMENT

The drug Leqembi works by clearing away some sticky amyloid but Sperling said it’s not clear if carriers of two APOE4 genes benefit because they have such a high risk of a side effect from the drug – dangerous brain swelling and bleeding. One research question is whether they’d do better starting such drugs sooner than other people.

Masliah said other research aims to develop gene therapy or drugs to specifically target APOE4. He said it’s also crucial to understand APOE4’s effects in diverse populations since it’s been studied mostly in white people of European ancestry.

As for gene tests, for now they’re typically used only to evaluate if someone’s a candidate for Leqembi or for people enrolling in Alzheimer’s research – especially studies of possible ways to prevent the disease. Sperling said the people most likely to carry two APOE4 genes had parents who both got Alzheimer’s relatively early, in their 60s rather than 80s.

Health

Origin of deadly cancer affecting young adults revealed in alarming report

Published

2 hours ago

March 4, 2026

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Origin of deadly cancer affecting young adults revealed in alarming report

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As colorectal cancer (CRC) is now the leading cause of cancer death in adults under 50, a new report reveals some surprising shifts in the incidence of the disease.

Although rates of CRC have been declining among seniors, those 65 and under are facing a rise in diagnoses, according to a report titled Colorectal Cancer Statistics, 2026, from the American Cancer Society.

Adults 65 and younger comprise nearly half (45%) of all new colorectal cancer cases — a significant increase from 27% in 1995, states the report, which was published in CA: A Cancer Journal for Clinicians.

The disease is rising fastest among adults 20 to 49 years old, at a rate of 3% per year.

Colorectal cancer is now the leading cause of cancer death in adults under 50. (iStock)

Among adults 50 and under, 75% of colorectal cancers are diagnosed at an advanced stage. Half of the diagnoses in that age range are made between the ages of 45 and 49. Although that age group is eligible to receive routine screenings, just 37% do so.

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The report also revealed that rectal cancer is on the rise, now accounting for about one-third (32%) of all CRC cases — an increase from 27% in the mid-2000s.

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“After decades of progress, the risk of dying from colorectal cancer is climbing in younger generations of men and women, confirming a real uptick in disease because of something we’re doing or some other exposure,” said Rebecca Siegel, senior scientific director, surveillance research at the American Cancer Society and lead author of the report, in a press release.

Among adults 50 and under, 75% of colorectal cancers are diagnosed at an advanced stage. Half of the diagnoses in that age range are made between the ages of 45 and 49. (iStock)

“We need to redouble research efforts to understand the cause, but also circumvent deaths through earlier detection by educating clinicians and the general public about symptoms and increasing screening in people 45-54 years.”

It is projected that 158,850 new cases of colorectal cancer will be diagnosed this year, and that the disease will cause 55,230 deaths, per the report.

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More than half of CRC cases can be linked to high-risk behaviors, the researchers said. Those include lack of nutrition, high alcohol consumption, smoking, lack of exercise and obesity.

“These findings further underscore that colorectal cancer is worsening among younger generations and highlight the immediate need for eligible adults to begin screening at the recommended age of 45,” said Dr. William Dahut, chief scientific officer at the American Cancer Society.

When the disease is caught at a local (early) stage, the five-year survival rate is 95%. (iStock)

“The report also shines a light on the crucial importance of continued funding for research to help discover new therapies to treat the disease and advance patient care.”

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When the disease is caught at a local (early) stage, the five-year survival rate is 95%, the report stated.

Melissa Rudy is senior health editor and a member of the lifestyle team at Fox News Digital. Story tips can be sent to melissa.rudy@fox.com.

Health

Aging process could accelerate due to ‘forever chemicals’ exposure, study finds

Published

14 hours ago

March 4, 2026

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Aging process could accelerate due to ‘forever chemicals’ exposure, study finds

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A new study suggests that middle-aged men may be more vulnerable to faster biological aging, potentially linked to exposure to “forever chemicals.”

The research, published in the journal Frontiers in Aging, examined how perfluoroalkyl and polyfluoroalkyl substances, more commonly known as PFAS, could impact aging at the cellular level.

PFAS are synthetic chemicals commonly used in nonstick cookware, food packaging, water-resistant fabrics and other consumer products, the study noted.

Their chemical structure makes them highly resistant to breaking down, allowing them to accumulate in water, soil and the human body.

Chinese researchers analyzed blood samples from 326 adults enrolled in the U.S. National Health and Nutrition Examination Survey between 1999 and 2000.

A new study suggests that middle-aged men could face accelerated biological aging at the cellular level due to exposure to PFAS. (iStock)

The researchers measured levels of 11 PFAS compounds in participants’ blood and used DNA-based “epigenetic clocks” — tools that analyze chemical changes to DNA to estimate biological age — to determine how quickly their bodies were aging at the cellular level, the study stated.

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Two compounds, perfluorononanoic acid (PFNA) and perfluorooctanesulfonamide (PFOSA), were detected in 95% of participants.

Higher concentrations of those chemicals were associated with faster biological aging in men of certain age groups, but not in women.

“People should not panic.”

The compounds most strongly linked to accelerated aging were not the PFAS chemicals that typically receive the most public attention, the researchers noted.

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“The associations were strongest in adults aged 50 to 64, particularly in men,” Dr. Xiangwei Li, professor at Shanghai Jiao Tong University School of Medicine and the study’s corresponding author, told Fox News Digital.

“While this does not establish that PFAS cause aging, it suggests that these widely present ‘forever chemicals’ may be linked to molecular changes related to long-term health and aging.”

The study found that two of the compounds were detected in 95% of participants, and higher levels were linked to faster biological aging in men ages 50–64. (iStock)

Midlife may represent a more sensitive biological period, when the body becomes more vulnerable to age-related stressors, according to the researchers.

Lifestyle factors, such as smoking, may influence biological aging markers, potentially increasing vulnerability to environmental pollutants.

While Li said “people should not panic,” she does recommend looking for reasonable ways to reduce exposure.

That might mean checking local drinking water reports, using certified water filters designed to reduce PFAS, and limiting the use of stain- or grease-resistant products when alternatives are available.

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Meaningful reductions in PFAS exposure will likely depend on broader regulatory action and environmental cleanup efforts, Li added.

The researchers noted that midlife could be a particularly sensitive stage, when the body is more susceptible to stressors associated with aging. (iStock)

Study limitations

The researchers outlined several important limitations of the research, including that the findings show an association, but do not prove that PFAS directly causes accelerated aging.

“The study is cross-sectional, meaning exposure and aging markers were measured at the same time, so we cannot determine causality,” Li told Fox News Digital.

The study was also relatively small, limited to 326 adults age 50 or older, which means the findings may not apply to younger people or broader populations.

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Researchers measured PFAS levels using data collected between 1999 and 2000, and today’s exposure patterns may differ.

Li added that while PFAS is known to persist in the environment and the body, these results should be validated through larger, more recent studies that follow participants over time.

Kelly McGreal is a production assistant with the lifestyle team at Fox News Digital.

Health

Melissa Joan Hart, 49, Opens up About Weight Loss in Perimenopause

Published

1 day ago

March 3, 2026

Press Room

Melissa Joan Hart, 49, Opens up About Weight Loss in Perimenopause

Melissa Joan Hart Opens up About Weight Loss in Perimenopause | Woman’s World

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