Progesterone Won't Shield Women Against Alzheimer's

Progesterone Won't Shield Women Against Alzheimer's
THURSDAY, Nov. 29 (HealthDay News) -- There's no evidence thatprogesterone -- which is often given with estrogen in hormone replacementtherapy -- offers women any protection against Alzheimer's disease, U.S.researchers say.
They conducted tests on female mice genetically engineered to developan Alzheimer's-like disease to come to this conclusion.
Treatment with estrogen blocked the Alzheimer's-like symptoms in themice, while treatment with progesterone did not. In fact, when the micewere given both hormones, progesterone appeared to block estrogen's mainbenefit -- preventing the buildup of beta amyloid protein in the brain, akey factor in Alzheimer's.
The researchers, led by gerontologist Christian Pike of the Universityof Southern California, did find that progesterone seemed to inhibit tauhyperphosphorylation, another chemical process implicated inAlzheimer's.
The study appears in this week's issue of the Journal ofNeuroscience.
Previous research suggested that estrogen offers women some protectionagainst Alzheimer's disease. The authors of this new study wanted todetermine if the same might be true of progesterone.
The findings may provide guidance for the design of human trialsexamining hormone therapy and Alzheimer's, Pike said. Future studies mayneed to focus on both the dosage and formulations of progestins (syntheticversions of progesterone given to humans), as well as the starting age forhormone therapy, he noted.
More information
The U.S. National Institute on Aging discusses whether Alzheimer's can be prevented.