A new study from Columbia University has revealed that warning signs linked to Alzheimer’s disease may appear much earlier in life than previously believed—even in people as young as their 20s and 30s.
The research shows that certain risk factors and biological markers tied to Alzheimer’s are already connected to cognitive performance in young and middle-aged adults, well before old age. This discovery could shift how we think about prevention and treatment of Alzheimer’s, pointing to the importance of protecting brain health from a much earlier age.
The study was led by Dr. Allison Aiello, an epidemiology professor at Columbia’s Butler Aging Center and the Mailman School of Public Health.
It is the first study of its kind to closely examine early-life Alzheimer’s risk factors and blood biomarkers in a large group of generally healthy U.S. adults under the age of 50. The findings were published in The Lancet Regional Health – Americas.
Until now, most Alzheimer’s research has focused on people aged 50 or older. But this study looked at data from thousands of people aged 24 to 44 who were part of the long-running National Longitudinal Study of Adolescent to Adult Health (known as Add Health).
This study began in the mid-1990s and has followed a large, diverse group of Americans across decades. The researchers used surveys, interviews, cognitive tests, physical exams, and blood samples to understand how risk factors and brain function relate in younger adults.
The researchers examined a tool called the CAIDE score, which measures a person’s risk of developing dementia based on things like age, education, blood pressure, body weight, cholesterol, physical activity, and whether they carry a gene called APOE ε4, which increases Alzheimer’s risk.
They also looked at biological indicators known as ATN biomarkers—short for amyloid, tau, and neurodegeneration—which are known to be involved in the brain changes seen in Alzheimer’s disease. These were analyzed along with immune and inflammation-related markers found in the blood.
The results showed that people in their 20s, 30s, and early 40s who had higher CAIDE scores generally performed worse on memory and attention tests. Some blood markers also showed a connection to how well people scored on these tests.
Interestingly, the presence of the APOE gene—considered a strong risk factor for Alzheimer’s in older people—was not linked to lower cognitive performance in this younger age group. This suggests that some genetic risks may take longer to show their effects, while other physical and biological risks are already active in early adulthood.
Dr. Aiello and her team believe these findings could help scientists predict who might be at greater risk of memory problems later in life, long before any symptoms appear. They emphasize that early prevention—such as managing heart health, reducing inflammation, and living a healthy lifestyle—could help reduce future cases of Alzheimer’s disease.
The study also supports the idea that Alzheimer’s disease doesn’t begin suddenly in old age, but rather develops slowly over many years, even decades. This means we may need to think about Alzheimer’s not as a disease of the elderly, but as a lifelong condition that requires lifelong attention.
In summary, this research suggests that important clues about future brain health are already present in young adulthood. Tracking and addressing these clues early—especially through better heart health, exercise, and reduced inflammation—might be one of the most effective ways to fight Alzheimer’s disease in the long run.
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The research findings can be found in The Lancet Regional Health—Americas.
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