Dementia Risk After 90: New Study Reveals Surprising Findings

Topic: Health

A new study followed over 800 people in their 90s to understand dementia risk. Researchers found that women are twice as likely to develop dementia as men, and black participants face a higher risk than Asian participants. The study also looked at the role of genetics in dementia.

People who live into their 90s might think they're safe from cognitive decline. But a new study shows that's not always true. Researchers at UC Davis Health and Kaiser Permanente wanted to know what happens to dementia risk after age 90. They followed over 800 people in their 90s as part of the LifeAfter90 study, which started in 2018.

The researchers found some surprising differences in dementia risk. Women were twice as likely to develop dementia as men. Black participants faced a higher risk than Asian participants. This is important because by 2100, there will be over 230 million people worldwide who are 90 or older.

The study also looked at the role of genetics in dementia. The APOE gene is strongly associated with Alzheimer's disease. Different versions of this gene can influence risk in opposite directions. Researchers found that carrying a protective version of the gene, called APOE2, lowered dementia risk by 60%. However, carrying another version, APOE4, increased risk among men and black participants.

One thing that surprised researchers is that some people with established dementia risk factors, like hypertension and high cholesterol, remained cognitively healthy into their 90s. This highlights an important mystery: why do some people stay healthy while others develop dementia?

Why It Matters

This study matters because India's population is aging rapidly. By 2050, over 20% of Indians will be above 60 years old. Understanding dementia risk and how to prevent it can help improve healthcare for older adults in India.

Key Facts

• The LifeAfter90 study followed over 800 people in their 90s to understand dementia risk.
• Women are twice as likely to develop dementia as men after age 90.
• Black participants face a higher risk of dementia than Asian participants.
• Carrying the APOE2 gene lowers dementia risk by 60%.
• The study found that some people with established dementia risk factors remained cognitively healthy into their 90s.

Key Terms

APOE

A gene strongly associated with Alzheimer's disease

Dementia

A condition where brain function declines, leading to memory loss and difficulty thinking

Cognitive decline

A decrease in mental abilities such as memory, attention, and problem-solving

Implications

This study matters because India's population is aging rapidly. By 2050, over 20% of Indians will be above 60 years old. Understanding dementia risk and how to prevent it can help improve healthcare for older adults in India.