Dementia Risk Continues Beyond Age 90

Reaching age 90 without dementia is often seen as escaping the condition. However, new research indicates that dementia risk persists well into advanced age.

Study Insights

Researchers from the University of California, Davis Health and Kaiser Permanente conducted the LifeAfter90 study, tracking over 800 adults aged 90 and older. The study focused on dementia risk factors, analyzing sex, race, ethnicity, and genetics.

The Lancet Healthy Longevity published the findings, examining dementia risk in a diverse group over 90 without initial signs.

Rachel Whitmer, UC Davis Health professor, highlighted differences in dementia rates after 90, noting women’s higher risk. She emphasized understanding those most affected by dementia post-90 and the role of the Alzheimer’s risk gene, APOE.

Research Methodology

Participants were Kaiser Permanente members, assessed every six months to monitor cognitive health changes. Historical health records, some dating back to the 1960s, provided additional insights.

Study Findings

• Women had double the dementia risk compared to men after age 90.
• Racial and ethnic disparities continued into advanced age. Black participants had a 75% higher risk than Asian participants.
• The incidence was significantly higher for Black and Hispanic participants compared to White and Asian participants.

Hilary Colbeth, a UC Davis postdoctoral scholar, emphasized the continuation of racial and ethnic disparities in dementia risk into the 10th decade of life.

APOE’s Role

Researchers analyzed the APOE gene, linked to Alzheimer’s disease risk. The APOE2 variant provided a 60% reduction in dementia risk after age 90. Conversely, APOE4 doubled dementia risk among Black participants and impacted males differently.

Colbeth’s observations prompted further study on APOE genotypes’ impact on mortality post-90.

Intriguing Observations

Some participants remained cognitively healthy despite early risk factors like hypertension or high cholesterol, or carrying APOE4. Understanding their protection now intrigues researchers.

Expert Perspective

Lisa George from Talk Tribeca Psychiatry highlighted misconceptions about aging and dementia. George warned that reaching 90 with intact cognition doesn’t guarantee future dementia immunity. She noted that multiple brain processes affect dementia in the “oldest old.”

George stressed memory concerns in older adults shouldn’t automatically signal dementia, as other conditions might mimic it. Memory complaints could arise from factors like depression, anxiety, poor sleep, or medication side effects.

Implications for Clinicians

Study authors stressed the importance of recognizing dementia risk in these groups after 90. Whitmer advised against assuming immunity for high-risk groups beyond 90, urging discussions on risk reduction.

Future Directions

The study highlights dementia risk extending past age 90, raising questions on aging, genetics, and health disparities’ role in cognitive decline. It underscores the need for targeted research on this fast-growing age group.

Alzheimer’s research is shifting towards earlier detection and prevention, with promising blood-based biomarker tests. These advances could steer future screening, treatment, and prevention strategies.