New research published in JAMA Neurology reveals that hormone therapy use more than five years after menopause is linked to increased levels of tau protein in the brain, while early use is not. The study sheds light on the heightened risk of dementia associated with later use of hormone therapy in women. Scientists from Harvard Medical School and the University of Wisconsin, Madison led the study and also discovered that women have higher tau levels compared to men, and earlier age at menopause is correlated with higher tau levels. The findings reinforce the safety of hormone use when initiated early during menopause. They suggest that tau plays a part in dementia risk when hormone therapy starts years after menopause, according to Rachel Buckley, PhD, the paper’s senior author and assistant professor of neurology at Harvard Medical School. The research drew data from the Wisconsin Registry for Alzheimer Prevention with 292 participants. Women on hormone therapy who had a higher amyloid-beta burden had higher tau degrees than non-hormone therapy users in most brain regions assessed. Women may take hormone therapy years after menopause if a physician recommends it as a preventive measure, or if they hesitated to start it initially but later begin as symptoms persist.
