(NaturalNews) Hormone replacement therapy may cause the brains of postmenopausal women to shrink, according to a study conducted by researchers from Wake Forest University and published in the journal Neurology.
Hormone replacement therapy, in this context, refers to the practice of dosing women with sex hormones such as estrogen and progesterone in order to diminish the symptoms of menopause. The practice has come under fire recently, however, after studies linking it to an increased risk of breast cancer and cardiovascular disease. Some studies have suggested that it might increase the risk of memory loss, dementia and other forms of cognitive decline.
In the current study, researchers scanned the brains of 1,400 women between the ages of 71 and 89, all of whom had previously participated in a study on hormone replacement therapy. Compared with women who had been given a placebo treatment, women who had undergone hormone replacement therapy had smaller brains – 2.37 cubic centimeters less volume in the front lobe, and 0.10 cubic centimeters less in the hippocampus.
"Our findings suggest that hormone therapy in older post-menopausal women has a negative effect on brain structures important in maintaining normal memory functioning," lead researcher Susan Resnick said.
She noted that the therapy might not be the cause of the shrinkage, however, but might have rather exacerbated preexisting problems.
"This negative effect was most pronounced in women who already may have had some memory problems before using hormone therapy," she said, "suggesting that the therapy may have accelerated a neurodegenerative disease process that had already begun."
Researchers remain unsure exactly how hormone replacement therapy interacts with the brain to increase the risk of shrinkage. Some have hypothesized that the therapy – already known to increase the risk of major strokes – might also increase the risk of smaller, "silent" strokes, thus leading to a gradual death of brain tissue. The current study found no such increase in the risk of silent strokes, however.