New Study Finds Early Signs of Alzheimer’s Risk in Adults Aged 24 to 44
New research from Columbia University (USA) reveals that memory and thinking differences linked to Alzheimer’s risk may begin much earlier than expected — even in people as young as 24. The study highlights the importance of taking care of brain health throughout adulthood, long before any symptoms appear.
Many people think Alzheimer’s disease only becomes relevant in old age. But a new study by researchers from Columbia University suggests that some of the earliest warning signs may start appearing much earlier — even in people in their 20s or 30s.
The study, published in The Lancet Regional Health – Americas (DOI: 10.1016/j.lana.2025.101087), found that certain risk factors linked to Alzheimer’s were already connected to differences in memory and thinking in young adults. This doesn’t mean these people are getting sick. Rather, it shows that the groundwork for later brain changes might begin decades before anyone notices symptoms.
These findings could change how we think about brain health and how early we should begin taking care of our minds.
Who Did the Study and How It Was Done
The research was led by Dr. Allison Aiello and a team of scientists from Columbia University and the University of North Carolina at Chapel Hill. They used data from a large national study in the United States called Add Health (short for the National Longitudinal Study of Adolescent to Adult Health).
Add Health started in the 1990s by following a group of American teenagers. Over time, the same people were surveyed again and again, giving researchers a rare chance to see how health changes across decades.
In this new project, the team focused on participants between the ages of 24 and 44. They looked at two waves of data collection:
- Wave IV: Around 11,000 participants aged 24 to 34 were interviewed in person. They completed memory and attention tests, had their blood pressure and weight measured, and gave blood samples.
- Wave V: Around 1,100 participants aged 34 to 44 continued with more testing, either online or in person.
The researchers were especially interested in three things:
- How well people performed on basic memory and attention tasks.
- Whether their physical health — like blood pressure, cholesterol, or body weight — affected their brain performance.
- What their blood revealed about brain-related proteins and immune system activity.
What Exactly Did They Test?
The team used a common tool called the CAIDE score, which adds up several risk factors — like age, sex, blood pressure, education level, cholesterol, and physical activity — to give an estimate of someone’s long-term dementia risk. This score is typically used for people over 50, but in this study, it was applied to much younger adults.
They also looked at what’s known as ATN biomarkers. These include three groups of brain-related proteins:
- A (Amyloid): A protein that can build up in the brain over time.
- T (Tau): Another protein linked to memory and thinking changes.
- N (Neurodegeneration): Signs that brain cells might not be functioning as they should.
In addition, the team measured inflammatory markers in the blood. These are signals from the immune system that sometimes show the body is under stress or reacting to something — even if a person feels totally fine.
What Makes This Study Unique
This is one of the first large-scale studies to explore how Alzheimer’s risk factors relate to brain performance in adults under 45. Previous research has mostly focused on older adults, usually after symptoms have already started.
This study stands out because it brings together different types of data — memory scores, physical health, genetics, and lab tests — in a group of young, mostly healthy people. It shows that brain-related differences might not begin in old age but could instead develop gradually over a lifetime.
What the Researchers Discovered
The team found several important connections between brain function and Alzheimer’s-related risks — even in people who had no signs of memory loss or illness.
- Memory and attention were linked to physical health even in the mid-20s. People with higher CAIDE scores — meaning more cardiovascular risk factors — tended to do slightly worse on memory and thinking tasks. For example, remembering a list of words or repeating numbers backward was harder for those with higher scores.
- Brain-related proteins like tau were already connected to thinking performance. Tau is one of the proteins that has been linked to brain aging. In people aged 34 to 44, those with more tau in their blood had lower memory scores, even though they didn’t report any memory problems.
- Signals from the immune system also played a role. Higher levels of certain immune markers — like IL-6, IL-1β, and IL-8 — were associated with slightly weaker memory and attention. This doesn’t mean these people were sick, but it may point to low-level stress in the body affecting the brain over time.
- A common genetic risk factor didn’t show effects yet. The APOE ε4 gene is a well-known genetic factor linked to Alzheimer’s in older adults. Interestingly, in this younger group, the gene didn’t yet seem to affect memory performance. That could mean its impact shows up later in life.
- There were no visible symptoms — but measurable differences still existed. None of the participants had clinical memory problems. Yet, differences in their test scores were linked to the risk factors above. This shows that changes in brain function might begin silently, long before they’re noticeable.
What Does This Mean for Brain Abilities Like Memory and Focus?
The results of this study are important because they show that cognitive abilities — like remembering things, paying attention, or solving problems — can be influenced by health factors very early in adulthood.
That’s good news in many ways. Why? Because many of the factors studied here — like exercise, blood pressure, and even immune health — can be improved or monitored over time. Our brains are flexible, and there’s growing evidence that memory and thinking can benefit from regular activity and challenges.
Activities like reading, solving puzzles, learning new skills, and using digital tools to train memory and attention can help the brain stay sharp. Starting these habits early may give the brain more support in the long run.
New study highlights the importance of acting early to protect cognitive function
The results of this study go far beyond academic research — they offer a new lens for understanding how memory and thinking skills develop and change over time, and what that could mean for everyday life.
For scientific research, the findings add weight to the growing understanding that Alzheimer’s disease is not simply a condition of old age. Instead, it may develop gradually over decades, with early signs appearing long before traditional risk groups are considered. This could push scientists to design studies that follow individuals over the long term, starting much earlier in life.
For healthcare professionals, the research opens the door to more comprehensive health assessments for younger adults. While the study does not suggest any need for diagnosis or treatment at this age, it does show the value of monitoring brain-related health factors — like blood pressure, cholesterol, or inflammation — in people long before midlife.
In education, the results highlight the importance of teaching young people about the role of brain health alongside physical well-being. Habits that support mental sharpness — such as regular sleep, physical activity, and staying mentally engaged — can begin early and strengthen over time. Schools and universities might include brain-friendly activities as part of a broader health curriculum.
Across society, the study suggests it’s time to broaden the conversation about Alzheimer’s risk and prevention. While much public attention remains focused on older adults, these findings underline the need to support cognitive health at every age. That could include community programs that encourage mental activity, movement, and healthy routines for all generations — not just seniors.
Ultimately, this study calls for a cultural shift: one where brain health is treated as a lifelong priority, not just a concern that comes with aging.
Final Thoughts: Early Brain Health May Be Key to Long-Term Cognitive Wellbeing
One of the most important messages from this study is that brain health is shaped much earlier in life than previously believed. According to the findings, even adults in their 20s or 30s — who typically feel healthy and show no cognitive symptoms — may already experience subtle effects of risk factors such as elevated blood pressure, cholesterol levels, or low physical activity.
Although these early differences may not directly signal disease, they reflect how everyday health patterns could already be shaping brain function. The study highlights the potential value of embracing preventive strategies early in adulthood, well before conventional risk ages.
The findings highlight the importance of prevention starting early in adulthood. Building healthy habits — such as staying physically active, engaging in mentally stimulating activities, getting enough sleep, and supporting emotional well-being — may help protect cognitive function over time. Tools like cognitive training programs, reading, or learning new skills can play a valuable role in keeping the brain active and adaptable for years to come.
The findings support a broader view of brain health as a lifelong priority. Rather than waiting for warning signs, the study encourages a proactive mindset: maintaining overall health, staying mentally active, and supporting the brain’s adaptability across all stages of adulthood.
