Women who use estrogen supplements from either before or at the beginning of menopause and continue use for a few years may be at a reduced risk of dementia due to the increase in the preservation of their brain structure, according to a new study by scientists from the Norwegian University of Science and Technology.

"Estrogen supplements can have a positive effect against dementia if women start early enough with treatment," Carl Pintzka, lead author of the study, said in a press release.

The study examined a sample of 80 women who had used estrogen supplements throughout the course of menopause and compared them to a group of 80 women who had never used estrogen supplements in their life. All of these women were previous participants of the Nord-Trøndelag Health Study (HUNT), a general population-based study in mid-Norway.

It is well-known that after menopause womens' estrogen levels drop considerably, and the current study links this drop to a decrease in the size of the brain. Magnetic resonance imaging (MRI) scans of the women in the study who had taken estrogen supplements throughout menopause had larger hippocampi than those who didn't. The hippocampus is an important brain structure for memory and sense of place, and its deterioration is an early indicator of Alzheimer's disease progression.

"We also examined the shape of the hippocampus and found that areas where hormone therapy had the greatest effect are the same areas that are affected by Alzheimer's disease in its early stages," Pintzka said.

Although these findings point to potential benefits in terms of protecting the brain against Alzheimer's, it still remains unclear whether the supplements actually protect against dementia. Further studies will need to be conducted to establish a causal relationship between estrogen supplementation beginning at menopause and a reduced risk of dementia.

The findings were published in the September issue of the Neurobiology of Aging.