Most women can’t wait to give Aunt Flo the boot. After all, she’s moody, messy and shows up uninvited every month.

But new research suggests that having more years between your first period and your last comes with some serious health perks later in life.

And it has nothing to do with what’s happening below the belt.

In the study, University of Auckland researchers analyzed brain scans from more than 1,000 postmenopausal women and spotted a striking pattern.

Individuals who experienced menarche at an earlier age, had a delayed onset of menopause, or a longer span of reproductive years, displayed a noticeable deceleration in the aging process of their brains.

Dr. Eileen Lueders, the primary investigator of the research, remarked, “These results bolster the hypothesis that estradiol, which is the most potent and prevalent form of estrogen during a woman’s reproductive stage, could potentially act as a safeguard for the aging brain.”

Research conducted on animals has indicated that estradiol contributes to the maintenance of brain function by fostering neuroplasticity, diminishing inflammation, and enhancing intercellular communication within the brain.

Estradiol levels fluctuate throughout a woman’s life. They rise sharply at puberty, stay high during most of the reproductive years, then drop steeply around menopause.

Previous studies have linked that decline in estradiol levels to an increased risk of dementia and other age-related brain conditions.

The findings suggest that health interventions, such as hormone treatment, in the years leading up to menopause and immediately after could help combat an increased risk of Alzheimer’s for some women, researchers said. 

The stakes are high: Women bear the brunt of the memory-robbing disease, making up about two-thirds of the 7 million cases across the US today, according to the Alzheimer’s Association.

In the US, girls usually start menstruating around age 12, though the Mayo Clinic reports that periods can begin as early as 8 or as late as 16.

The years when a woman menstruates and can get pregnant are called the reproductive phase. This stage ends with menopause, which is officially diagnosed after a woman has gone 12 months without a period.

The average women in the US hits menopause around age 51, but it can happen anytime from the 30s to the mid-50s or later, according to the federal Office on Women’s Health. 

The age you enter menopause is influenced by several factors, including genetics, lifestyle and certain medical conditions. For example, women who smoke may enter menopause earlier, while having multiple pregnancies can delay its onset.

“As more women weigh the benefits of hormone therapy during menopause, findings like these spark important conversations and open the door to more inclusive, focused research in women’s brain health,” said Alicja Nowacka, a PhD student at the University of Auckland who wasn’t involved in the study.

While the new research adds to the growing evidence that estradiol may help protect brain health, Lueders cautioned that the effects were small and estradiol levels were not directly measured.

She also noted that other factors, such as genetics, lifestyle and overall health, can play a role in brain aging. 

Looking ahead, Lueders is urging future studies to include a more diverse pool of participants and directly measure their hormone levels to better understand how estradiol and other factors impact women’s brain health.