Scientists are reevaluating the causes of Alzheimer's beyond the amyloid hypothesis

Untreated hearing loss is linked with dementia risk

Hearing loss does not cause dementia, but it does increase the risk of developing dementia and research suggests that people who wear hearing aids for age-related hearing loss also maintain better brain function than those who don't.

Hearing loss is linked with brain volume reductions

The brain looks different as a result of hearing loss, with reductions in brain volume overall and in specific areas, and these changes are hypothesized to impact cognition. Exactly why hearing loss alters cognition is an active area of research, but theories include that the elevated cognitive load of straining to hear affects brain power available for thinking and memory and that hearing loss leads to social isolation which boosts dementia risk.

"Plaques" and "tangles" are top potential causes of Alzheimer's—but questions remain

The exact causes of Alzheimer's—and how to treat it—continue to be the subject of intense research. Two leading factors are amyloid beta plaques and tau protein tangles, which effectively pile up in the brain and interfere with neurons and cause cell death, which manifests as memory loss and other symptoms.

Alzheimer's disease is the leading cause of dementia and risks rise after age 65

Read this primer about Alzheimer's disease and learn what factors increase the risk of this form of dementia, including genetics, being a woman, and health conditions, including high blood pressure.

Is conventional wisdom about amyloid plaques wrong?

Neurobiologist Karl Herrup makes the case for reevaluating current research paradigms and embracing a more comprehensive understanding of Alzheimer's disease. He highlights years of failed clinical trials of drugs reducing amyloid plaques in treating Alzheimer's, the establishment of that theory based on a single patient, and more.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

Alzheimer's brain changes may begin years before symptoms appear

The debilitating disorder degrades cognitive abilities. Its symptoms may start with subtle memory issues, but by the time patients notice any changes, neural changes may already be progressing, such as the accumulation of beta-amyloid plaques between neurons and tau protein tangles within them.

There are two FDA-approved blood tests that may detect early Alzheimer's disease

Yet the tests are only recommended for those who have symptoms of dementia, and are not definitive on their own. False positives are a concern with these new tests, which detect biomarkers that may indicate the presence of brain proteins linked to the disease. This podcast explores the state of research on the disease and concerns about regulators taking jobs at pharmaceutical and biotech companies, which may influence their approach to approvals. It also dives into an investigation about the data underpinning one experimental Alzheimer's drug.

Researchers are exploring neural links between Alzheimer's and autism

Recent DNA sequencing and molecular biology studies suggest that similarities in genes, neural circuitry and patterns of disease warrant further exploration to potentially better understand both conditions and how to treat them. (Some users may encounter a paywall.)

Some dementia cases may be linked to microorganisms in the brain

Researchers now know that, much like the gut, the brain is home to an ecosystem of microorganisms—the brain microbiome. While this area of study is still new, some scientists believe 50% of bacteria-caused dementia cases could be treated. (Some users may encounter a paywall.)

More than 200 drug trials for Alzheimer's have failed or been abandoned since 2010

The complexity of Alzheimer's disease, coupled with decades of underfunded research efforts, has left patients with little in the way of effective treatments. In recent years, scientists have synthesized several drugs that studies show can slow the progression of Alzheimer's—though the disease itself remains incurable.

Listen to how one gene affects Alzheimer's risk

Multiple genes are associated with Alzheimer's risk, but one well-known disease-associated gene is the apolipoprotein E (APOE) gene, which is typically involved in making a protein that helps carry cholesterol and other fats in the bloodstream. Specific variants of this gene are associated with elevated disease risk, though even if someone has two copies of the disease, that doesn't mean they will definitely develop Alzheimer's.

How Alzheimer’s disease becomes fatal

Despite more than 100,000 people with Alzheimer's dying each year, the specific cause of death is not the disease itself. Often, secondary diseases arise from complications with the disease, including pneumonia, severe falls, malnutrition, or infection. Read more about the range of complications caused by Alzheimer’s here.

Does our fear of Alzheimer's create stigma around its treatment?

Surveys suggest our fear of Alzheimer's as a disease outranks that of heart disease and cancer. This piece argues our fear of aging and the slipping away of our mental capacities make it more difficult to treat Alzheimer's compassionately.

How neurodegeneration happens, the underlying disease process of dementia

Dementia symptoms may vary between individuals, and may include mood changes, difficulty walking, speaking, and memory problems. It can progress over many years, occurring due to progressive damage to nerve cells in the brain. This degradation may happen for myriad reasons, and its triggers are under investigation.

Poor sleep increases the risk of developing Alzheimer's

Brain imaging studies reveal poor sleep leads to production of amyloid beta proteins—molecules linked to Alzheimer’s—which are cleaned from the brain during high-quality sleep. These findings suggest conditions like sleep apnea and insomnia increase the risk of developing the disease.

Age-related hearing loss, known as presbycusis, is a top cause of hearing loss

This video walks through the biology of why presbycusis (prez-buh-kyoo-sis) occurs and its etiology. This type of hearing loss is gradual and typically starts with reductions in the ability to hear high-pitched sounds.

MS Drugs reduce inflammation, helping reduce relapses and slow disease progression

Disease-Modifying Drugs calm the body's inflammatory response to help stave off relapses—when new or existing MS symptoms show up for a day or longer. Avoiding smoking, exercising, reducing stress via mindfulness, checking for vitamin D deficiencies, drinking more water and eating well, all can slow disease progression. [The jury's still out on if HRT around the time of menopause may reduce dementia risk](https://www.thelancet.com/journals/lanhl/article/PIIS2666-7568(25)00122-9/fulltext) Estrogen can reduce inflammation and support neural growth in the brain, and some research has suggested that beginning hormone replacement therapy around menopause—versus later in life—reduces Alzheimer's disease risk. Still, a recent systematic review concluded that taking HRT didn't affect dementia risk, regardless of when women started taking it, so the science remains unsettled.

A top Alzheimer's researcher was accused of faking results

In 2021, an investigation revealed photo manipulation in images from a seminal 2006 paper by researcher Sylvain Lesné on the role of amyloid plaques in progressive Alzheimer's disease. The revelation rocked the field, leaving many wondering whether they had tried to build on fabricated results. (Some users may experience a paywall.)

Analysis finds dementia was rare in ancient Greece

Ancient medical texts seldom mention severe cognitive decline, suggesting that such conditions were uncommon. This scarcity is attributed to factors like shorter lifespans and active lifestyles, implying that modern environmental and lifestyle changes—along with longer life expectancy—contribute to the current prevalence of dementia.

The first identification of Alzheimer's was made in 1906

The first case of Alzheimer's disease dates to the early 20th century when Dr. Alois Alzheimer had 51-year-old Auguste Deter as a patient. Deter struggled with sudden memory issues and aggressive, irrational behavior. After Deter's death, Alzheimer examined her brain and found strange collections of molecular pileups.

How aging degrades neural functioning in the brain over time

Aging affects the brain perhaps more than any other organ in the body. Throughout life, the brain experiences radical shifts in the number of neurons, synaptic connections between neurons, and hormone levels that regulate our mood and processing.

Some data links schizophrenia to older paternal age and birth complications

Yet both associations are not yet considered firm enough to definitively be causative. Schizophrenia is a multi-causal syndrome and a mixture of factors, including genetics, are widely believed to be behind its development.

Smell is a robust memory cue for individuals with Alzheimer's disease

Odor is more effective than both visual and verbal cues for triggering autobiographical recall in Alzheimer's disease, according to 2021 research.

Long-term memory issues among West Nile survivors may be from immune response, not virus

Rodent research suggests that long-term neurological complications such as fatigue, weakness, difficulty walking, and memory loss, may be due to the immune system systematically destroying parts of neurons in the brain in response to the infection, rather than due to viral infection itself.

Rodent evidence is mounting that dysfunctional mitochondria may be a cause of Parkinson's

Though researchers have long observed mitochondrial malfunction in Parkinson's patients, it has remained unclear whether faulty mitochondria cause the disease or are casualties of it. Rodent research published in 2025 adds further weight to the idea that it's causative.

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

Recent research found that the brain doesn't seem to massively rewire following amputation—upending earlier beliefs about the cause of phantom limb pain.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

Indefinite cloning of some endangered species may not sustain their longevity because cloning success rates decrease as genetic mutations accumulate.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

Against his wishes, Albert Einstein's brain was removed before his cremation, and the pathologist responsible stored it for decades in mason jars within a beer cooler.

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

In 1939, baseball star Lou Gehrig delivered his inspirational 'Luckiest Man' speech after retiring due to the health condition that now bears his name.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Scientists have struggled to pin down Ebola's natural reservoir species for decades, but the available evidence suggests that it's very likely fruit and insect-eating bats found in Africa.

In recent years a child anxiety expert has created and tested a novel phobia and anxiety treatment approach for children, focused on changing how parents respond to the fears.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

A researcher recently discovered an interview from 1967 between groundbreaking journalist Joan Didion and the Grateful Dead, years before the band became an institution.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

The hormonal disorder PCOS was renamed PMOS in 2026, a move designed to improve care and research by shifting the focus to the hormonal causes of this condition that affects 1 in 8 women.

Clever Hans was a 1900s horse that was believed to be able to solve math equations, tell time, and read and comprehend German, until a psychology student discovered how he got his answers.

Poison ivy will likely become both larger and more resilient due to climate change.

Electrical grids worldwide must double their power delivery capacity by 2050 to meet surging demand from AI and electric vehicles.

US consumers collectively owe more than $1T to credit card companies—almost as much as they owe in auto loans.

The Nasdaq's 'Magnificent 7' companies are responsible for roughly 40% of the Nasdaq 100 index's gains, while the remaining 93 companies account for the other 60%.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

The story of Dollree Mapp, whose legal challenge over her 1957 conviction for possessing "obscene material" led to a major strengthening of the Fourth Amendment

Many legends about George Washington, including his supposed wooden teeth and the story of cutting down the cherry tree, lack evidence.

US intelligence allegedly pursued more than 600 schemes to assassinate Cuban revolutionary Fidel Castro.