As debate continues to rage over the risks and benefits of hormone therapy, emerging medical evidence suggests certain women who take estrogen to relieve menopausal symptoms could be protected from Alzheimer’s disease.
“If a woman is having hot flashes, our data suggest that she would benefit from hormone therapy,” said Pauline Maki, a U.S. researcher who specializes in the effects of sex hormones on brain function.
“And the best data that we have suggest that she will not experience Alzheimer’s disease by virtue of having been exposed to that.”
Maki, who directs the women’s mental health research program at the University of Illinois at Chicago, spoke Friday at a conference sponsored by the Royal Ottawa Health Care Group.
“What we’re telling women is if you have hot flashes and they’re impairing you and affecting your everyday function, don’t be scared to test it out. See what it does to your memory and be in control of your own health care,” said Maki.
Her research team led a 2007 study of 180 healthy post-menopausal women between the ages of 45 and 55, who were randomly assigned to receive either estrogen pills, or a placebo. After four months, they were given memory tests — the most reliable assessment of whether someone is at high risk for Alzheimer’s.
The study found no evidence of harm to the memory of study participants — if they took estrogen-only pills. The finding has been verified by five other randomized controlled trials, including another one led by Maki that followed 800 women over five years.
While more studies are needed in a larger study sample, the finding challenges conventional wisdom about the risks of some hormones used in menopause.
The result is likely to surprise women and their doctors, who for years have heard frightening news about the risks of hormones, which were once touted as every woman’s key to lasting youth, health and femininity. However, in 2002, a massive U.S. study of 161,000 women found that hormone therapy raised the risk of several serious illnesses, including breast cancer, heart attacks, stroke and dementia.
The study, known as the Women’s Health Initiative, found that many of the treatment’s expected benefits never materialized. In fact, the use of a combination of two hormones, estrogen and progestin, raised the risk of some diseases that they were supposed to prevent.
A related study, called the Women’s Health Initiative Mental Study, found that hormone therapy doubled the risk of Alzheimer’s and other types of dementia in women who began the treatment at age 65 or older.
The study was widely considered to be the most reliable and scientifically rigorous of the many studies on hormone therapy because it was the largest experiment to compare women on hormones with a group taking placebos.
Many women gave up hormone therapy after the studies came out. Before it was published, about six million women were taking combination therapy.
Maki’s research, however, reflects a gradual shift in understanding of how changing hormone levels can affect a woman’s mind as well as her body as she ages. Indeed, hormone variations are a key factor in why Alzheimer’s and depression are more common in women, while Parkinson’s disease and autism are more common in men.
Similarly, women tend to exercise less than men, which also has an effect on the brain. Exercise promotes the growth of cells and blood vessel and protects both the heart and the brain by controlling blood pressure.
However, Maki warned that estrogen therapy is not a panacea. “Women still need to do the hard work and keep their hearts healthy and exercise. And that’s the best way they can prevent Alzheimer’s disease.”