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Even In Your 90s, This Gene May Have A Say In Brain Health
Why does one person stay sharp well into their 90s while another starts having trouble with everyday tasks?
Age is part of the picture, but researchers are also looking at how our genes might influence different aspects of brain health. One gene in particular, APOE, is already known for its connection to Alzheimer's disease.
In a recent study of adults over 90, researchers explored whether different versions of this gene were associated with changes in memory, focus, and decision-making, offering a closer look at how these abilities can change differently as we age.
About the study
The APOE gene comes in several versions, including APOE ε4 and APOE ε2. APOE ε4 is the strongest known genetic risk factor for late-onset Alzheimer's disease, while APOE ε2 is associated with a lower risk.
Researchers wanted to understand whether these variants were also linked to changes in specific thinking skills among adults in their 90s and beyond.
To investigate, the team followed 445 adults between ages 90 and 104 in the ongoing LifeAfter90 study.
Participants were 93 years old on average, and 59% were women. Researchers analyzed DNA from saliva samples and assessed three cognitive abilities every six months for about four years.
These included executive function (planning, focusing, and making decisions), semantic memory (remembering facts and general knowledge), and verbal episodic memory (recalling words and personal experiences).
One gene variant may affect focus, while another may protect memory
The two APOE variants were associated with different patterns of cognitive change.
About 20% of participants carried APOE ε4. Compared with people who didn't carry it, they experienced faster declines in executive function, the skills that help us plan, stay focused, and make decisions.
Their general knowledge and ability to recall words and personal experiences, however, declined at similar rates to those of non-carriers.
APOE ε2 showed a different association. About 15% of participants carried this variant, and their verbal episodic memory declined more slowly than that of non-carriers. Their executive function and general knowledge followed similar patterns to the rest of the group.
Neither variant was significantly associated with the risk of dying during the study.
Researchers also accounted for the possibility that participants with certain health risks might die before further cognitive changes could be measured. The link between APOE ε4 and faster executive function decline remained even after this adjustment.
What these findings tell us about brain aging
Memory, focus, and decision-making are connected, but they aren't interchangeable.
This study suggests that APOE variants may be associated with changes in certain cognitive skills without affecting them all in the same way.
However, the findings show associations, not proof that either variant directly causes these changes. The study also can't tell us what will happen to any one person.
Carrying APOE ε4 doesn't mean someone will develop Alzheimer's disease, just as carrying APOE ε2 doesn't guarantee protection.
Everyday ways to support your brain as you age
You don't need to know your APOE status to make choices that support your overall brain health. This study doesn't establish new recommendations for genetic testing or Alzheimer's prevention, but there are several practical habits worth prioritizing.
- Move your body regularly: Walking, cycling, dancing, or strength training can support overall health as you age. Choose activities you enjoy so they're easier to maintain.
- Protect your sleep: Aim for a consistent sleep schedule and give yourself enough time to rest. If sleep problems persist, speak with a health professional.
- Keep learning: Try a new recipe, pick up a hobby, or learn a skill that challenges you. The goal is to keep engaging with activities that require attention and thought.
- Make time for people: Call a friend, share a meal, or join a group built around an interest you enjoy. Meaningful social connections are another valuable part of healthy aging.
These habits can't eliminate genetic risk, but they offer practical ways to support your health without treating your genes as a fixed prediction of your future.
The takeaway
Even in your 90s, your genes may influence which thinking skills change first.
This study linked two APOE variants to different patterns of cognitive decline, but neither one tells the whole story of how a person's brain will age. Your genes may set part of the stage, but they don't always run the show.