Almost two out of three Americans with Alzheimer’s disease are women, yet we only have some dubious theories to explain why.

Is it caused by genetics? Differences in brain anatomy? Hormones? All of the above? Scientists aren’t sure.

But another possibility has emerged. Aging affects a woman’s stress response differently from a man’s. This in turn has an impact on memory. Here’s what I mean…

Stressful Life Experiences Are Commonplace

Do stress hormones act differently in men and women to bring about differences in cognition as they age?

That question was explored by Cynthia Munro, associate professor of psychiatry and behavioral sciences at Johns Hopkins University School of Medicine.

She and her team gathered data on 909 residents of Baltimore, almost two-thirds of whom were women, in 1981.

They were interviewed and had health check-ups on four occasions – at the time they were enrolled, again in 1982, between 1993 and 1996 — when they averaged 47 years of age — and then again between 2003 and 2004.

During the third check-up in the 1990s, the volunteers were asked if they had experienced a traumatic or stressful life event in the previous year.

Stressful events were deemed to include physical attacks, muggings, threats, living through a natural disaster or seeing another person attacked or killed. Between a quarter and a fifth of both men and women reported that they had.

The researchers also questioned the participants about any stressful life experiences in the previous year such as marriage, divorce, job loss, retirement, severe injury or sickness, a son or daughter moving out of the family home, the birth of a child, or death of a loved one. Almost half the participants said they had suffered stress as a result of at least one of these experiences.

On their third and fourth meetings with the researchers, the Baltimore residents underwent memory tests. As expected, there was a decrease in performance after the fourth meeting since this took place some years after the third. This drop was then compared to the reported number of stressful life events and experiences.

Women’s Stress Response Triple that of Men

What Dr. Munro and her team discovered was that one-off stressful events such as a death in the family did not increase the risk of dementia for either sex, but chronic, long-term stress sometimes did. What’s more, the outcomes were different for men and women.

Unlike men, middle-aged women who experienced chronic stress had a greater decline in memory over a decade later.

The researchers also found no link between stress in earlier life and memory in either women or men.

Dr. Munro explained that chronic ongoing stress from life experiences has an impact on the brain which is more detrimental than distinct traumatic events.

“A normal stress response causes a temporary increase in stress hormones like cortisol, and when it’s over, levels return to baseline and you recover,” she said.

“But with repeated stress, or with enhanced sensitivity to stress, your body mounts an increased and sustained hormone response that takes longer to recover. We know if stress hormone levels increase and remain high, this isn’t good for the brain’s hippocampus—the seat of memory.”

Although stress hormones were not measured in the study, Dr. Munro points out that other studies have shown that with aging, the stress response in women is three times greater than in men. This study adds to the evidence that stress hormones play an uneven role in men and women.

She went on to say that stress reduction hasn’t had much attention compared to other factors that contribute to Alzheimer’s.

“We can’t get rid of stressors, but we might adjust the way we respond to stress and have a real effect on brain function as we age,” she added.

How to Respond to Stress

Harvard Health suggest six relaxation techniques we can use to develop a healthy stress response. The authors recommend one or more of these, practiced for 20 minutes a day.

  1. Breath focus. Take long, slow, deep breaths. As you breathe, gently disengage your mind from distracting thoughts and sensations.
  2. Body scan. After a few minutes of the above, focus on one part of the body or group of muscles at a time and mentally release any physical tension you feel there.
  3. Guided imagery. Spend several minutes imagining relaxing and soothing scenes, places, or experiences.
  4. Mindfulness meditation. Sit comfortably, focus on your breathing, bring your mind’s attention to the present moment only.
  5. Yoga, tai chi, and qigong. These combine rhythmic breathing with a series of postures or flowing movements.
  6. Repetitive prayer. Silently repeat a short prayer or phrase from a prayer while practicing breath focus.

My further comment on all this is that the Johns Hopkins study is not the last word. I would want to see the findings confirmed.  And finally, stress is known to take a big toll on the body. It contributes to other medical problems such as heart disease and high blood pressure, and reduces your chance of recovery from illnesses you may already have.

You want to avoid it.