New Estrogen Findings Challenge Assumptions About Aging Brains

WHO:

Fast Company - Researchers examined 352 cognitively unimpaired women.

Fast Company - The study’s authors said the long-term effects of naturally produced and externally supplied estrogen fluctuations on late-life cerebral small vessel disease remain poorly understood.

Fast Company - Former FDA Commissioner Marty Makary said, “With few exceptions, there may be no other medication in the modern era that can improve the health outcomes of women at a population level more than hormone replacement therapy,” describing its long-term benefits as “tremendous.”

The Washington Post - Neurobiologist Anna Marseglia studies forces that shape the aging brain and became increasingly curious about estrogen as she entered her 40s.

WHAT:

Fast Company - A study published in the journal *Neurology* found that women with longer lifetime estrogen exposure through oral birth control and menopausal hormone therapy had fewer physiological markers associated with Alzheimer’s and healthier brains overall.

Fast Company - Participants had brain MRIs at age 70 and again five years after their first scan.

Fast Company - Longer reproductive spans—years between the start and end of periods—have been associated with reduced brain aging later in life.

Fast Company - The article says estrogen-based drugs may be supplied through birth control pills, hormonal patches, and topical creams.

Fast Company - The FDA removed black box warning labels from hormone-based drugs used for perimenopause and menopause symptoms. The warnings had cautioned about possible heart risks and blood clots.

Fast Company - Estrogen patches were in a nationwide shortage, which the article links to increased interest in treatment for symptoms including brain fog, hot flashes, depression, and anxiety.

WHERE:

Fast Company - The article describes the estrogen-patch shortage as nationwide.

WHY:

Fast Company - Estrogen may support cognitive health by reducing inflammation, boosting blood flow, and protecting white matter, which connects neurons.

Fast Company - The authors wrote that longer lifetime estrogen exposure may provide neuroprotection, while abrupt estrogen loss may increase neuropathology accumulation and dementia risk.

HOW:

Fast Company - The study assessed brain health using MRI scans and compared outcomes with women’s lifetime estrogen exposure.

Fast Company - The article says Alzheimer’s is almost twice as common in women as in men.

(UPDATED November 5, 2026 23:08 UTC)

Longer lifetime estrogen exposure was linked to healthier brains and fewer Alzheimer’s markers in women. The study suggests estrogen may protect brain tissue, though long-term effects remain uncertain. The FDA removed warning labels from menopause hormone drugs as patches face shortages.