In 2024, nearly 7 million Americans were living with Alzheimer’s disease, which is the most common form of dementia, according to statistics from the Alzheimer’s Association. The group estimates the number will rise to nearly 13 million by 2050. Worldwide, 55 million people live with the neurodegenerative disease.
Alzheimer’s is the fifth-leading cause of death among those 65 and older, and health and long-term costs for those who live with dementia was projected to be $360 billion in 2024. The lifetime risk for Alzheimer’s at age 45 is 1 in 5 for women and 1 in 10 for men. Overall, 1 in 9 older adults has the disease.
It’s no wonder there’s great interest in dementia research worldwide.
Here’s a small sampling of recent interesting findings — most in the very early stages and likely to lead to much more study — in the quest to understand and hopefully one day prevent or at least effectively treat (Dare we dream of a cure?) the disease. Despite recent advances, none of that is yet possible.
Diabetes medications may stave off Alzheimer’s
Two drugs used to lower glucose for patients with diabetes may also protect those patients from Alzheimer’s disease and related dementias, according to research from the University of Florida College of Pharmacy.
For a study published in JAMA Neurology, the researchers pored over Medicare claims data of older adults with Type 2 diabetes, looking for the association between use of glucagon-like peptide-1 receptor agonists (GLP-1 drugs) and sodium-glucose cotransporter-2 inhibitors (often called SGLT2is) to see the rate of Alzheimer’s disease and related dementias.
The popular drug Ozempic is an example of a GLP-1 drug.
They found significantly lower rates of the dementias among those who used those medications, as opposed to other glucose-lowering drugs, suggesting the drugs may have neuroprotective effects, which they hope would also extend to people without diabetes.
A link between ADHD and dementia?
Attention deficit disorder might be linked to increased risk of dementia later in life, according to a study from University of Geneva and the Geneva University Hospitals that finds patients with attention deficit disorder — with or without hyperactivity — have more iron in certain parts of their brains and more neurofilaments in their blood than folks without the disorder. Those markers are also characteristics frequently reported in age-related dementias, including Alzheimer’s disease.
The study is published in the journal Psychiatry and Clinical Neurosciences.
The World Health Organization has reported that just under 1 in 28 adults have ADHD, which is marked by inability to maintain attention, as well as higher levels of hyperactivity and impulsivity. Typically, symptoms show up in childhood, but can persist well into adulthood.
Close to 55 million older adults have age-related dementia, of which Alzheimer’s is by far the most common, representing 60-70% of cases.
“Recent epidemiological studies show that adults suffering from ADHD have an increased risk of dementia at an advanced age,” said Paul G. Unschuld, head of the Division of Geriatric Psychiatry at the hospitals and an associate professor in the university’s department of psychiatry. He added that the mechanics of the link is unknown.
Unschuld believes that prevention efforts aimed at those with ADHD could reduce the risk of dementia and suggests that long-term studies could see if reducing iron levels in the brain could prevent dementia in the future for those who have ADHD.
Brain injuries and alcohol consumption
Those who have eight or more alcoholic drinks a week have greater risk of developing hyaline arteriolosclerosis, a type of brain lesion that’s associated with memory and thinking problems. That’s according to a study in Neurology.
The Sao Paulo, Brazil, research team noted the findings don’t prove drinking causes brain injury, but they note an association.
With hyaline arteriolosclerosis, small blood vessels narrow, thickening and stiffening. That restricts blood flow and damages the brain over time.
Study author Alberto Fernando Oliveira Justo of the University of Sao Paulo Medical School in Brazil called heavy drinking a major global health concern.
The study included the autopsied brains of 1,781 people who were average age 75 at the time of their death. The researchers looked for indicators of brain injury including the arteriolosclerosis and tau tangles. They also measured the brain weight and height of participants.
Alcohol consumption was determined by interviewing family members of the deceased.
The researchers assigned the people into categories of never drank, moderate drinkers (seven or fewer a week), heavy drinkers (eight or more) and heavy drinkers who stopped drinking. A drink contained 14 grams of alcohol.
After adjusting for age at death, smoking and physical activity, they said heavy drinkers had 133% higher odds of developing brain lesions compared to those who never drank, while former heavy drinkers had 89% higher odds and moderate drinkers had 60% higher odds.
Both heavy and former heavy drinkers also had greater risk of developing tau tangles, which are associated with Alzheimer’s disease.
Former heavy drinking was also associated with smaller brain mass and lower cognitive ability, though no link was found between moderate or heavy drinking and lower brain mass or cognitive ability.
The study also showed that heavy drinkers died roughly 13 years earlier than those who never drank.
The study had limitations, including the fact that it looked at participants after death and did not consider how long people drank and their cognitive ability.
ALS drug may treat Alzheimer’s disease
A Northwestern University study suggests that experimental drug NU-9, which has been authorized by the U.S. Food and Drug Administration for clinical trials to treat amyotrophic lateral sclerosis (ALS, also called Lou Gehrig’s disease) improves neuron health in animal models of Alzheimer’s disease.
Both ALS and Alzheimer’s result from misfolded proteins that damage the brain. Instead of treating symptoms, NU-9 addresses how the brain misfolds, providing hope that the drug might be effective in multiple neurodegenerative diseases.
The drug’s effectiveness won’t be known until it’s tested in humans, “but how well upper motor neurons function in mice is similar to how well they function in humans. So it seems to me, NU-9 really should work,” said the drug’s inventor, Northwestern’s Richard B. Silverman.
The study was published in the Proceedings of the National Academy of Sciences.
Is eye health linked to dementia?
Blood vessels in the back of the eye — the retinal microvasculature — may show early signs someone is at risk of developing dementia, per a study by researchers at Ōtākou Whakaihu Waka and the University of Otago in New Zealand.
While it’s too soon to apply findings in the real world, the research is promising, according to the team. It’s believed that early detection is crucial with dementia, but cognitive tests aren’t sensitive enough. And technology that can show brain changes including amyloid plaques and tau tangles, such as MRI and PET scans, are expensive and not available to everyone.
The retina connects directly to the brain. “It’s thought that many of the disease processes in Alzheimer’s are reflected in the retina, making it a good target as a biomarker to identify people at risk of developing dementia,” said Dr. Ashleigh Barrett-Young from the university’s psychology department.
The study, which used eye scan data, was published in the Journal of Alzheimer’s Disease.
“This research is still at an early stage and we can’t predict your future looking at an eye scan,” Barrett-Young said. “Hopefully, one day we’ll be able to use AI methods on eye scans to give you an indication of your brain health, but we’re not there yet.”
A blood test that rules out future dementia risk?
Researchers at Karolinska Institutet in Stockholm, Sweden, have shown that specific blood biomarkers can predict development of dementia up to 10 years before symptoms appear. But their primary value would be to rule out the likelihood of developing dementia in the next decade, rather than providing accurate early screening, they said.
Findings were published in the journal Nature Medicine.
While 83% accurate in testing on 2,100 older adults 60-plus in terms of who went on over the decade to develop dementia, it is not accurate enough, they warned, to say with certainty who will develop dementia. Rather, the blood test could be a tool to reassure folks they are unlikely to develop dementia within the decade.
“Our findings imply that if an individual has low levels of these biomarkers, their risk of developing dementia over the next decade is minimal,” said Davide Vetrano, associate professor at the institute and the study’s senior author. “This information could offer reassurance to individuals worried about their cognitive health, as it potentially rules out the future development of dementia.”
He added, “These biomarkers are promising, but they are currently not suitable as stand-alone screening tests to identify dementia risk in the general population.”