- The Alzheimer’s Association held its international conference in Toronto.
- The conference unveiled new research about Alzheimer’s, which impacts 7 million Americans.
- New findings include studies showing lead exposure has been linked to cognitive decline.
More than 7 million Americans live with Alzheimer’s disease, and a third of older adults eventually die with Alzheimer’s or another form of dementia, according to 2025 data from the Alzheimer’s Association. The lifetime risk for Alzheimer’s at age 45 is 1 in 5 for women and 1 in 10 for men.
And nearly 12 million Americans currently provide care for someone with Alzheimer’s or other dementias. But it’s not just a challenge for individual families. Dementias are expensive and will cost the U.S. more than $384 billion this year alone.
The Alzheimer’s Association has been in Toronto this week for its international conference, which concluded Thursday. A Deseret News story earlier this week explored findings on exercise and lifestyle changes in older adults. Here are some of the studies that made conference news.
Lead hard on cognition
A trio of studies say lead exposure should be added to factors that could make a brain vulnerable to Alzheimer’s disease.
In a news release from the gathering, the Alzheimer’s Association noted that “historic lead levels from the era of leaded gasoline may be contributing to cognitive issues 50 years later.” It said “Americans are about 20% more likely to experience memory problems if they lived in areas with high levels of atmospheric lead between 1960 and 1974,” based on data from more than 600,000 adults ages 65 and older.
“Research suggests half the U.S. population — more than 170 million people — were exposed to high lead levels in early childhood. This research sheds more light on the toxicity of lead related to brain health in older adults today,” said María C. Carrillo, Alzheimer’s Association chief science officer and medical affairs lead.
She cited other studies reported at the conference that suggest lead exposure at any point in life can create cognitive challenges and there is a “biological connection” between being exposed to lead and developing Alzheimer’s disease. She also noted that some populations may be more vulnerable.
The study led by a researcher at the Centre for Addiction and Mental Health in Toronto looked at airborne lead exposure in those years when leaded gasoline use was common, calculating historic atmospheric lead levels by geographic area. Researchers then compared that to memory problems that were self-reported by participants in recent waves of the American Community Survey.
The researchers didn’t analyze the source of the lead but believe that the higher the density of automobile traffic, which one finds in urban areas, the higher the atmospheric lead. They concluded that 17% to 22% of people living in areas with moderate, high or extremely high atmospheric lead related issues with their memory.
Changes in use of lead in gasoline have greatly reduced risk of atmospheric lead, but there are other sources, including old lead paint and pipes, per the release.
A different study found older adults living around three miles from a lead-releasing facility — such as those producing glass, ready-mix concrete or computer and electronics — are more prone to thinking and memory problems than those living farther away.
There were reportedly 7,507 lead-releasing facilities in the U.S. in 2023. Kathryn Conlon, associate professor of environmental epidemiology at University of California Davis’ medical school, recommends those living near a lead-producing facility keep their homes clean to avoid accumulation of dust containing lead, remove their shoes when they go inside and place dust mats inside and out to avoid tracking lead dust.
A third, related study at the conference simulated lead exposure through contaminated water or air to demonstrate how it might impact the brain. It showed lead exposure is linked to more tau and amyloid beta in the brain and can create cognitive problems decades later.
SNAP may slow cognitive decline for low-income seniors
Food assistance programs may help protect against age-related cognitive decline for low-income seniors, according to a study that compared older adults who participated in the U.S. Supplemental Nutrition Assistance Program to those who didn’t. They found SNAP participants had a slower decline in cognitive function over the decade-long study period, “effectively maintaining an average of two to three additional years of cognitive health,” compared to those who didn’t, per a news release from the international conference.
The comparison was between those who qualified for the program but did not participate and those who did.
“The findings highlight the potential of food assistance programs to support cognitive health in the aging population and point to the need for additional efforts to reduce disparities in cognitive aging across different racial and ethnic groups,” per the researchers, from University of Georgia College of Public Health.
“This is one of the first long-term studies to show that food assistance programs can positively impact cognition,” said Carrillo. “Simple, everyday actions can make a difference in brain health and may even lower the risk of Alzheimer’s disease and dementia.”
She said eating right is one of the association’s 10 Healthy Habits for Your Brain.
Blood tests to triage or diagnose
The Alzheimer’s Association has released its first clinical practice guidelines on use of blood-based biomarker tests to diagnose Alzheimer’s. The recommendations apply only to patients with cognitive impairment who are being seen by specialty medical experts for memory disorders.
The guideline notes that there is what Alzheimer’s Association regional spokesman James Herlihy writes is “significant variability in diagnostic test accuracy.” Some of the blood tests aren’t considered accurate enough.
But those with at least 90% sensitivity and specificity are good enough to take the place of the positron emission tomography (PET) amyloid imaging or cerebral spinal fluid Alzheimer’s biomarker testing.
The guidelines say those meeting 90% or better for sensitivity and 75% for accurate specificity can be used as a triage test “in which a negative result rules out Alzheimer’s pathology with a high probability.” A positive result should be confirmed with another method, such as a PET scan or the cerebrospinal fluid test.
The association said the blood biomarker tests are not a substitute for a thorough clinical evaluation by a health care professional. But the group notes that the blood tests are “typically less costly, more accessible and more acceptable to patients.”
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