Gene Variant Increases Alzheimer's Risk in Women

Research history — originally published April 23, 2014. This article discusses a 2014 study, not a newly released finding. Reviewed October 3, 2026.

What the 2014 study measured

A Stanford-led study published in Annals of Neurology examined how APOE4 and sex relate to progression from normal cognition to mild cognitive impairment or Alzheimer's, and from mild impairment to Alzheimer's.

The researchers analyzed 5,496 cognitively healthy participants and 2,588 participants with mild cognitive impairment. They also examined spinal-fluid biomarkers in 980 participants. Among initially healthy participants, APOE4 carriers were more likely to progress, with a stronger association in women. In the mild-impairment group, results depended on the genotype comparison; the overall sex interaction was not statistically significant.

These findings concern specific study populations and progression outcomes. They should not be turned into a single lifetime-risk multiplier for everyone with one APOE4 copy. Carrying a risk variant does not guarantee that a person will develop Alzheimer's.

Why it matters for care planning

The Alzheimer's Association estimates that 7.4 million Americans age 65 and older are living with Alzheimer's in 2026 and projects roughly 13.8 million by 2060. A plan for cognitive impairment considers supervision, help with daily activities, and family caregiving alongside paid services.

For the coverage and caregiving questions, read Long Term Care Insurance and Alzheimer's.