A Woman's Brain Needs Sex Hormones

No estrogen is more than fertility loss in females: they can turn demented. Later in life. Women with their ovaries removed and not getting extra estrogen are prone to high risk of cognitive impairment or dementia in later life.

This is opposite to the results of a 2004 research made at the Women's Health Initiative (WHI) on 7500 older women, which detected a higher risk of dementia in women aged 65 to 79 who received estrogen supplements in their hormone replacement therapy after menopause. It seems that this hormone has different effects at different ages.

But the team led by neurologist Walter Rocca of the Mayo Clinic College of Medicine in Rochester, Minnesota, investigated premenopausal women who had one or both ovaries removed between 1950 and 1987, due to medical issues or as a protection against cancer. Their medical records came from Olmsted County, Minnesota.

The researchers interviewed 1489 subjects and discovered that 10% had developed dementia, compared to a control group of 1472 women who had intact ovaries, in which the number was of 6.6%.

"The findings suggest that it's harmful to have too little estrogen before menopause, and make a strong case for estrogen treatment if ovaries are removed before age 50," wrote the researchers.

The results match other study, which investigated how monkeys' brain was affected by estrogen, when their ovaries had been eliminated just before the menopause.

"When we looked at the prefrontal cortex, the neurons had been restored to a youthful state, and this strongly supports this new research," said neurobiologist John Morrison at the Mount Sinai School of Medicine in New York.

"Where and when estrogen switches from being protective to harmful is the next big question," said Rocca.

"A randomized clinical trial may be necessary to confirm the results. But the paper fits with earlier observational studies showing women who had their ovaries removed at a young age were at increased risk of cognitive decline," said biostatistician Mark Espeland of Wake Forest University in Winston-Salem, North Carolina.