Estrogen Therapy May Reduce Alzheimer’s Signs

Women are more likely to develop Alzheimer’s disease than men. However, women who use estrogen as part of hormone therapy after menopause show fewer signs of Alzheimer’s in their brains after death, according to a study published in Neurology.

Previous studies on hormone therapy have been unclear. Some suggested estrogen might protect against dementia, while others found no benefit or even potential risks, especially when started after age 65. Many earlier studies relied on tests like cognitive assessments or blood work, which are less reliable than examining the brain itself after death.

Hadi Hosseini, a neuroscientist at Stanford University, explained that the key gap in previous research was the lack of postmortem brain analysis, which provides clearer evidence of Alzheimer’s disease.

Hosseini and his team analyzed data from over 5,000 women aged 50 and older. They focused on a small group who used estrogen-only hormone therapy. This type of therapy is often prescribed to women who have had hysterectomies due to the increased risk of endometrial cancer with estrogen alone.

The researchers examined three key signs of Alzheimer’s in the brains: amyloid plaques, tau-related tangles, and neuritic plaques. These protein deposits can disrupt brain function and are reliable indicators of the disease.

They found that women who used estrogen-only therapy had a 35% lower chance of severe Alzheimer’s markers in their brains compared to those who did not use hormone therapy. Additionally, these women had fewer signs of Alzheimer’s while alive, including lower levels of amyloid in blood and cerebrospinal fluid and reduced odds of memory loss or functional decline.