A new study finds that early menopause may increase the risk of Alzheimer’s disease.
And according to the study, taking hormone therapy may help offset this risk.
Hormone therapy has a controversial past, but experts stress the importance of helping it treat menopausal symptoms.
About 5.8 million people in the United States have Alzheimer’s disease and related dementia, and women are twice as likely to develop the condition as men. Now, a new study has found that the age at which women begin menopause may be a factor in the development of Alzheimer’s — but that hormone therapy (HT) could help offset that risk.
The study published in Gama is a neurologisty, analyzed the brain scans of 193 women and 99 men who had not been diagnosed with alzheimer’s disease or other forms of dementia to look for signs of beta-amyloid plaques and tau proteins, two markers of alzheimer’s disease.
The researchers discovered that women in general had more tau buildup in several parts of the brain than men of the same age, along with more amyloid plaques. All of the women in the study used some type of hormone therapy, which is a combination of estrogen and progestin, which is a synthetic form of the hormone progesterone. The results indicated that women who entered menopause before the age of 40, from ages 40 to 45, or who started hormone therapy more than five years after menopause began had higher levels of tau in their brains.
But the researchers also found that people who started HT treatment around the time they started menopause did not have an increased risk of developing tau proteins in the brain, suggesting that menopause treatment may reduce the risk of developing Alzheimer’s disease.
Ultimately, the researchers concluded that entering menopause at an early age and starting hormone therapy late after menopause begins could contribute to how well tau develops in a woman’s brain.
The average age by which women experience menopause is 51, according to the American College of Obstetricians and Gynecologists (ACOG), but some women may begin menopause before age 40.
Research on the connection between menopause and Alzheimer’s disease is ongoing, and there is also a controversial history behind hormone therapy. However, you may have some questions. Here’s what we know so far.
Does early menopause increase a woman’s risk of dementia?
Data has linked early menopause with an increased risk of dementia later in life. One study published last year found that women who began menopause at age 45 were 30% more likely to develop dementia before age 65 than women who began menopause at age 50.
Early menopause “may be an important sex-specific risk factor for developing Alzheimer’s,” says Verna Porter, MD, a neurologist and director of dementia, Alzheimer’s disease, and neurocognitive disorders at Providence Saint John’s Health Center in Santa Monica, California. More research is needed.
There are also other risk factors that are thought to be involved in the development of Alzheimer’s disease. According to the National Institute on Aging (NIA), these can include:
My heart disease
high blood pressure
Does lack of estrogen cause Alzheimer’s disease?
ACOG explains that as a woman goes through menopause, her estrogen levels drop, which leads to classic symptoms like hot flashes, mood swings, and vaginal dryness. However, some researchers have theorized that low levels of estrogen may lead to Alzheimer’s disease, and this has not been conclusively proven. Researchers have found that lower estrogen levels over longer periods of time can cause oxidative stress, which can affect cognitive function.
“Here’s what we know: Estrogen has a profound effect on the brain,” says Lauren Streicher, MD, professor of obstetrics and gynecology at Northwestern University Feinberg School of Medicine. “There are estrogen receptors throughout the gray and white matter and you can see changes in postmenopausal women.”
But Dr. Streicher says things “get a little sticky when you look at Alzheimer’s disease” and hormone therapy. People hesitate to say, Take hormonal therapy to prevent Alzheimer’s disease– Not because it’s not necessarily true, but because it hasn’t been proven yet, ”says Dr. Streicher. But these data don’t surprise me. We know that estrogen has a profound effect on the brain. This may be a further indication that taking hormone therapy early can prevent risk Alzheimer’s disease in the future.
There is data to support estrogen therapy if a woman’s ovaries are removed, says Mary Jane Minkin, MD, clinical professor of obstetrics, gynecology, and reproductive sciences at Yale University School of Medicine. “If a woman has her ovaries out before age 45 and hasn’t been replaced with estrogen, we have good data that her risk of dementia is greatly increased,” she says. “The question is what about a 51-year-old woman going through menopause — does giving her estrogen prevent dementia? It’s less straightforward and controversial.”
Dr. Porter calls this study “interesting,” adding, “The results of this study may inform discussions of Alzheimer’s disease-related female reproductive health risks and treatment.”
There is controversy about HT, but doctors say there shouldn’t be
At the most basic level, hormone therapy (formerly known as hormone replacement therapy) involves taking estrogen and possibly progestin to replace the hormones your body loses during menopause, ACOG explains.
Hormone therapy has been found to be the best treatment for hot flashes and night sweats, along with vaginal dryness and bone loss, according to the ACOG. However, preliminary results were published in 2003 from the Women’s Health Initiative clinical trial that linked a combination of estrogen and progestin with an increased risk of heart disease, stroke, blood clots, dementia, and breast cancer—and the study was discontinued early as a result.
But the results were later debunked. The researchers found that the original study looked at women 65 and older who already had a higher risk of heart attack, stroke, blood clots, and more, skewing the data. The study also did not take into account how old these women were when they started hormone therapy.
Since then, data has shown that using estrogen with a certain type of progesterone may increase breast cancer risk, but not estrogen alone. “Mironized progesterone is preferred because it is not associated with breast cancer,” says Dr. Streicher.
And again, HT timing matters. “If women start hormone therapy late — more than 10 years after the onset of menopause — the damage may already have been done, whether it’s from tau proteins or changes in blood vessels,” says Dr. Streicher.
Dr. Porter agrees. “These findings are consistent with clinical guidelines that hormone therapy is relatively safe when used near the onset of menopause, but may pose an increased risk of developing Alzheimer’s dementia if started later,” she says.
Dr. Streicher urges women to consider the data on hormone therapy. “You are more likely to die of heart disease than breast cancer because of hormone therapy,” says Dr. Streicher.
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