Older age not the only culprit for more incidence of Alzheimer’s among women, researchers say
By Deborah Jeanne Sergeant
Researchers assumed that it’s because women tend to outlive men on average and older age is one of the risk factors for developing Alzheimer’s.
However, a recent study published in Neurology, “Sex-Driven Modifiers of Alzheimer Risk,” indicates there’s more to it than longevity.
Researchers found that hormones appear to make a difference in risk.
Though the study used a small sample — 85 women and 36 men — the results point to a higher number of vital biomarkers for Alzheimer’s disease among women who have experienced menopause, whether natural or bilateral hysterectomy menopause.
This factor was identified as associated with Alzheimer’s biomarkers more than age, health history, and comorbidities that increase risk such as diabetes, high cholesterol, smoking, poor diet and lack of exercise. Women using estradiol hormone therapy exhibited fewer factors that indicate development of Alzheimer’s.
It’s still not clear why most women who transition through menopause will not develop Alzheimer’s and some will, nor is it clear if estrogen is a direct or indirect factor.
“One concept emerging is that a woman’s reproductive history has been correlated with Alzheimer’s risk,” said physician Anafidelia Tavares, senior director of program for the Alzheimer’s Association and statewide research liaison.
Women with multiple live births seem to have lower their risk of Alzheimer’s as do women with early onset menses and later menopause. Though this points to correlation with hormonal influences, Tavares said that more research is necessary to draw conclusions.
In addition, Tavares said that known factors such as more years of formal education and more challenging mental stimulation place women currently in their older years at a disadvantage. The traditional pattern for this generation of women was to get married out of high school, stay home to rear children and not engage in employment or much social interaction. Though currently, more women than men are enrolled in college, that was not the case 50 years ago.
Today’s young women may find in their older years that their higher education and opportunities for employment and mental engagement are protective. But other factors, such as delaying childbearing and limiting the number of children may mitigate the benefits of more intellectual stimulation. Tavares said that it’s hard to tell how these correlative factors will affect women.
“That’s why it’s important we have this research to understand the drivers and the increased risk in women,” Tavares said. “We need to look at the modifiable risk factors.”
Older age a factor
Family history represents a non-modifiable risk factor; however, physician Marla Bruns, board member and medical science committee member with the Rochester and Finger Lakes Chapter of the Alzheimer’s Association, tells patients worried about family history that longevity is a much bigger risk factor, with Alzheimer’s present in one in nine people over 65; one in six of those over 75; and one in three over 85.
She also said that a 2018 study of 14,595 women indicated that mothers of three or more have a 12% lower risk compared with women who had only one child. Anytime a woman reported a miscarriage, she had a 9% higher risk compared with women who had never miscarried. Women who had their first period at age 13 or younger had less risk, but those who were 16 or older had a 31% greater risk.
Bruns said this appears to indicate that hormones play a role in Alzheimer’s risk.
“It’s very interesting how reproduction history can have that much impact,” she said. “A lot of people joke about ‘pregnancy brain’ or ‘menopause brain’ but it may be protective in some ways.”
She advises women to pay more attention to self-care.
“If you have a family history or even if you don’t, disease modifying factors can include staying active physically, mentally and socially,” Bruns said. “The Mediterranean diet can help, especially during pregnancy and menopause.”
In general, what’s good for the heart is good for the brain when it comes to diet, exercise and stress, she said.
Women tend to be the primary caregivers for both children and their elderly parents, in-laws and other relatives. This adds additional stress to their lives, along with the tendency for women to stretch themselves too thin to help others.
“It takes a lot of time and can cause burnout,” Bruns said. “Women can silently ignore their own needs and suffer depression.”
Tavares encourages lifestyle changes to reduce risk of Alzheimer’s and improve overall health, including a healthful diet, tobacco cessation, prevention of brain injury (such as avoiding risky behaviors and wearing seatbelts and bike helmets), and engaging in regular physical activity.
“Staying socially engaged, treat depression, and get a good night’s sleep,” Tavares said. “These are brain protective.”