Featured Research

from universities, journals, and other organizations

Effects Of Progesterone On Alzheimer's Disease

Date:
November 28, 2007
Source:
University of Southern California
Summary:
The first study on progesterone and Alzheimer's disease has found no clear preventive benefit for the widely prescribed hormone in an animal model. Progesterone is given with estrogen in hormone replacement therapy. Previous studies have suggested that estrogen offers women some protection against Alzheimer's disease.

The first study on progesterone and Alzheimer's disease has found no clear preventive benefit for the widely prescribed hormone in an animal model.

Progesterone is given with estrogen in hormone replacement therapy. Previous studies have suggested that estrogen offers women some protection against Alzheimer's disease.

The study's authors, led by gerontologist Christian Pike of the University of Southern California, asked if the same could be true of progesterone.

In a study highlighted in this week's issue of the Journal of Neuroscience, Pike's group reports that progesterone has only limited benefit for mice with Alzheimer's symptoms when taken alone.

When taken with estrogen, progesterone actually inhibits some of the other hormone's beneficial effects, the study found.

The problem is not necessarily progesterone itself, Pike said. It could be the constant daily dosage, which fails to replicate the pre-menopausal body's natural cycles of hormone production.

"This is probably not the best way to be delivering progesterone," Pike said. "Giving a constant dose of progesterone appears to antagonize a lot of the beneficial effects of estrogen."

Pike's group tested progesterone on female mice whose hormone production had been blocked to simulate menopause. The mice, which were genetically predisposed to develop an Alzheimer's-like disease, showed symptoms within months.

Treatment with estrogen reversed the symptoms, Pike's group reported. Treatment with progesterone did not.

When the two hormones were given together, progesterone appeared to hinder estrogen's main beneficial function: preventing the buildup of beta amyloid protein, the key risk factor in Alzheimer's.

"Estrogen no longer decreases the amount of beta amyloid" when progesterone is present, Pike said.

Progesterone's effects were not all bad, Pike added. The hormone appeared to inhibit tau hyperphosphorylation, another chemical process implicated in Alzheimer's.

Progesterone also is known to counteract the increased risk of endometrial cancer from estrogen therapy, which is one reason most women receive both hormones.

Pike said his group's study should provide guidance for the design of human trials studying hormone therapy and Alzheimer's. He added that future studies might need to focus both on the dosage and the formulation of progestins -- the synthetic versions of progesterone given to humans -- as well on the starting age for hormone therapy.

Prior to the study, "we really had no idea what the progestins were doing," Pike said.

The study was funded by the National Institute on Aging under a large grant to USC's Roberta Brinton, (Progesterone in Brain Aging and Alzheimer's Disease), who is leading a university-wide effort to study the effects of hormone therapy on women's health.

Doctors prescribe hormone therapy to counter some of the harmful consequences of menopause, such as losses in bone density. But other large studies have shown that hormone therapy also increases the risk of breast cancer.

"Our study mirrors to some extent recent clinical observations in women that hormone therapy appears to have both beneficial and deleterious effects," Pike said.

The other authors of the study were USC graduate students Jenna Carroll and Emily Rosario along with Lilly Chang, research lab specialist in obstetrics and gynecology at USC, Frank Stanczyk, professor of research in obstetrics and gynecology at USC and neurobiologists Salvatore Oddo and Frank LaFerla at the University of California, Irvine.


Story Source:

The above story is based on materials provided by University of Southern California. Note: Materials may be edited for content and length.


Cite This Page:

University of Southern California. "Effects Of Progesterone On Alzheimer's Disease." ScienceDaily. ScienceDaily, 28 November 2007. <www.sciencedaily.com/releases/2007/11/071127173334.htm>.
University of Southern California. (2007, November 28). Effects Of Progesterone On Alzheimer's Disease. ScienceDaily. Retrieved August 20, 2014 from www.sciencedaily.com/releases/2007/11/071127173334.htm
University of Southern California. "Effects Of Progesterone On Alzheimer's Disease." ScienceDaily. www.sciencedaily.com/releases/2007/11/071127173334.htm (accessed August 20, 2014).

Share This




More Health & Medicine News

Wednesday, August 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Possible Ebola Patient in Isolation at California Hospital

Possible Ebola Patient in Isolation at California Hospital

Reuters - US Online Video (Aug. 20, 2014) — A patient who may have been exposed to the Ebola virus is in isolation at the Kaiser Permanente South Sacramento Medical Center. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Raw: World's Oldest Man Lives in Japan

Raw: World's Oldest Man Lives in Japan

AP (Aug. 20, 2014) — A 111-year-old Japanese was certified as the world's oldest man by Guinness World Records on Wednesday. Sakari Momoi, a native of Fukushima in northern Japan, was given a certificate at a hospital in Tokyo. (Aug. 20) Video provided by AP
Powered by NewsLook.com
Do More Wedding Guests Make A Happier Marriage?

Do More Wedding Guests Make A Happier Marriage?

Newsy (Aug. 20, 2014) — A new study found couples who had at least 150 guests at their weddings were more likely to report being happy in their marriages. Video provided by Newsy
Powered by NewsLook.com
Ebola-Hit Sierra Leone's Freetown a City on Edge

Ebola-Hit Sierra Leone's Freetown a City on Edge

AFP (Aug. 19, 2014) — Residents of Sierra Leone's capital voice their fears as the Ebola virus sweeps through west Africa. Duration: 00:56 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins