The Perfect Time to Start Hormone Therapy to Slash Dementia Risk

woman using patch for hormone replacement therapy — adriaticfoto / Shutterstock

Neurological diseases are particularly worrisome as we age—but dementia is not an inevitability. While there are different lifestyle factors that can up your chances, there are thankfully also things you can do to lower your dementia risk. According to a new study, one such tactic is hormone therapy, which is used to treat symptoms of menopause. While hormone therapy has been debated in terms of its effects on women's health, new research suggests that it could be an effective strategy to prevent Alzheimer's disease, specifically—if you start at the right time. Read on to find out what researchers say is the ideal window for this treatment.

Investigators evaluated data from over 50 prior studies.

A senior woman sitting on the couch and holding her head with an anxious look — Shutterstock / fizkes

A study published last month in Frontiers in Aging Neuroscience looked at the use of hormone therapy and its effectiveness in reducing Alzheimer's disease, the most common form of dementia. Alzheimer's is much more prevalent in women, who have twice the risk of developing the disease in their lifetime when compared to men.

Investigators performed a meta-analysis—meaning they looked at data from other studies without collecting new information. They evaluated six clinical trials and 45 observational studies where women were given hormone therapy in mid-life and late-life, per a press release from Weill Cornell Medicine. Altogether, researchers looked at data from over six million women.

Women who started treatment younger had lower dementia risk.

woman going through menopause having a hot flash — Shutterstock

When compared with women who didn't receive hormone therapy, researchers found that women who started taking estrogen-only hormones during perimenopause (the transitional stage that lasts roughly four to eight years) or early menopause to treat symptoms had a 32 percent lower chance of developing dementia. Interestingly enough, for women who started taking estrogen over 10 years post-menopause, there was no significant lowering of dementia risk rate.

"There's a window of opportunity," lead study author Lisa Mosconi, PhD, director of the Alzheimer's Prevention Program and the Women's Brain Initiative at Weill Cornell Medicine in New York, told CNN. "Hormones work best for the brain when taken in midlife in presence of menopausal symptoms to support women through the menopause condition."

Estrogen-only treatment yielded better results.

Woman Doing Hormone Replacement Therapy — SPP Sam Payne Photography / Shutterstock

Investigators also looked at combination hormone therapy, where women were given estrogen and progestogen during perimenopause or early menopause. While there was a reduced risk here, too, researchers found that it wasn't statistically significant.

It's worth noting that estrogen alone is generally given to women after a hysterectomy (the removal of a uterus). For women with an intact uterus, they are typically given combination therapy to reduce the risk of uterine cancer. Per the press release, study researchers believe progesterone might "blunt the preventive effect of mid-life estrogen."

Doctors also don't recommend starting hormone therapy solely because you think it will lower your dementia risk, as Stephanie Faubion, director of Mayo Clinic's Women's Health and medical director of the Menopause Society, told The Wall Street Journal. If you do have symptoms like hot flashes or trouble sleeping, medical professionals say that's when you can consider treatment.

Estrogen has long been considered a factor in women's dementia risk.

woman looking at hormone replacement therapy package — Image Point Fr / Shutterstock

Researchers were specifically looking at estrogen because previous studies have found that it may have a protective effect on women's brains, per the Weill Cornell release. So, the loss of this hormone during menopause might explain why so many more women develop Alzheimer's disease versus their male counterparts.

Still, it's difficult to say for sure if estrogen protects against these conditions, because Alzheimer's typically occurs decades after women go through menopause in their earlier 50s.

"It isn't really feasible to run a clinical trial of estrogen therapy for that length of time to look for a dementia-preventing effect," Mosconi said in the release. "We need more clinical trials evaluating the effects of midlife hormone therapy on biological indicators of Alzheimer's disease, which we can now measure using brain imaging and fluids such as blood."

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Abby Reinhard Abby Reinhard is a Senior Editor at Best Life, covering daily news and keeping readers up to date on the latest style advice, travel destinations, and Hollywood happenings.Read moreFiled UnderBrain Health • Health Advice • Medicine • NewsSources referenced in this article