A big study found that older women who took estrogen‑only hormone therapy had a lower chance of getting dementia.
Study Details
Scientists looked at medical records from two large groups, together adding up to 21,462 women. The women were, on average, 71 years old when the study started and were followed for three to five years.
About 1,950 women used estrogen‑only therapy, usually starting after they turned 70. The rest, more than 19,500 women, never used the therapy.
What They Found in the Brain
After some participants died, researchers examined their brains. Women who had taken the therapy were less likely to show the three main signs of Alzheimer’s disease: amyloid‑beta plaques, tau tangles, and neuritic plaques.
Only 18% of the therapy users showed no Alzheimer’s signs, compared with 10% of non‑users. At the opposite end, 40% of therapy users had all three signs, while 51% of non‑users did.
When the team adjusted for age, education, genetics, race, and high blood pressure, estrogen therapy was linked to a 35% lower odds of having Alzheimer’s‑related brain changes.
Blood and Spinal Fluid Tests
While the women were alive, doctors also measured biomarkers in their blood and spinal fluid. Those who used estrogen had lower levels of amyloid‑beta, suggesting less plaque buildup in the brain.
Women on the therapy were 39% less likely to receive a clinical diagnosis of dementia and showed fewer memory problems in daily life.
How This Differs From Today’s Practice
It’s important to note that the participants started therapy around age 70. Today, doctors usually begin hormone therapy in the late 40s to early 50s and stop before age 60.
Even with this difference, the research points to a possible link between later‑life estrogen‑only therapy and better brain health.
The study was funded by the National Institute on Aging.