Midlife Memory Loss in Women: What to Know
Around menopause, many women report experiencing mental “fuzziness”—things like difficulty concentrating, blanking out on names, losing their train of thought, misplacing items, and forgetting appointments.
In fact, memory complaints around this time are quite common: Some studies report that as many as 60 percent of women notice such “unfavorable” memory problems at midlife.
If you are one of those women or know one, you may be wondering what’s responsible for these memory-related snafus. More worrisome: Are they a harbinger of more serious memory problems in the years ahead? And what—if anything—can be done about them?
The role of hormones
It’s easy to attribute these memory glitches to hormonal changes, particularly the decline in estrogen; after all, hormonal fluctuations are a hallmark of the perimenopausal transition (the time from the first signs of approaching menopause through one year after the final menstrual period).
And in the not-too-distant past, doctors routinely prescribed hormone therapy (HT) to postmenopausal women to boost diminished estrogen levels. One of the benefits, they believed, was protection from memory impairment.
Although a number of observational studies lent support to the idea that estrogen plays a protective role in the brain, others did not.
But no one was expecting the surprising results from a large randomized controlled trial published in 2003 in JAMA, which showed that HT use in postmenopausal women actually increased the risk of dementia. This finding, along with concerns about adverse cardiovascular and cancer risks associated with HT, caused doctors to stop routinely recommending it.
Although the JAMA study results provided powerful evidence that attempting to boost estrogen levels with HT can adversely affect the brain—most likely because of an increased risk of strokes—they don’t disprove the link between declining estrogen levels and memory troubles. Thus the theory that declining estrogen levels affect a woman’s memory remains a plausible one.
Evidence in support of this contention comes from brain imaging and observational studies. For example, British researchers performed magnetic resonance imaging (MRI) studies in premenopausal women who voluntarily underwent pharmacologic treatment to suppress their production of estrogen and progesterone. The MRIs showed decreased activation in areas of the brain involved in verbal memory. Brain function returned to normal when hormone levels returned to normal.
Also noteworthy: The areas of the brain affected—the hippocampus and prefrontal cortex—contain large numbers of estrogen receptors. These findings suggest that estrogen withdrawal might have an adverse effect on the brain’s ability to process verbal information.
Another study involving 24 perimenopausal women provides additional clues. Researchers assessed the women’s moods, menopausal symptoms, and overall health.
The women were also asked how well they thought their memory was functioning; 79 percent reported some degree of memory loss and 46 percent said that the impairment was moderately severe or worse.
The women also underwent cognitive testing that measured their ability to store (encode) and retain new information. Working memory (the ability to keep information in mind while using that information to complete a task) was also assessed.
Interestingly, the results, which were reported in Menopause, showed no association between the women’s memory complaints and their performance on tests of memory retention.
However, the women who had significant complaints about their memory function tended to perform worse on tests of working memory and encoding.
This suggests that the memory problems may not have been due to the brain’s ability to retain and retrieve new information; instead, the issue may have been the brain’s ability to store the information in the first place. The region of the brain implicated in this case? The estrogen-rich prefrontal cortex.
The cortisol connection
The study in Menopause also reported that women with memory complaints had more symptoms of depression and anxiety and sleep disturbances than those who didn’t have memory issues; not surprising, since feelings of depression or fatigue can compromise attention and memory in their own right. But the connections may be more complex.
Other research has found that symptoms of depression and anxiety are associated with fluctuations in the functioning of the hypothalamic-pituitary-adrenal axis. This “alliance” between the hypothalamus and the pituitary and adrenal glands regulates the release of cortisol (a stress hormone), which is produced in greater amounts after a hot flash.
Some researchers suspect that higher levels of cortisol could be the link between the increase in symptoms of depression and anxiety and the memory complaints reported by some women during perimenopause.
How long will it last?
Evidence from two studies—the Rochester Investigation of Cognition Across Menopause and the Study of Women’s Health Across the Nation (SWAN)—suggests that the subtle memory changes associated with perimenopause are temporary. But when these changes are most likely to occur is not clear.
In the 2013 Rochester study, researchers categorized 117 middle-aged women according to reproductive stage; they then assessed six different aspects of the women’s cognition and their menopausal symptoms.
On measures of verbal learning, verbal memory, and motor function, women in early postmenopause (the first year after menopause) performed significantly worse than those in the late reproductive and late menopausal transition stages. (These stages were defined as subtle changes in menstrual pattern and no menses for 60 days to 12 months, respectively.)
The women in early menopause also performed more poorly on attention and working memory tasks than women in the late menopausal transition.
The SWAN study, which involved more than 2,000 middle-aged women, also showed diminished verbal memory and processing speed; however, the problems occurred during late perimenopause (no menses for three to 11 months) and improved during the postmenopausal period (no menses for 12 months or more).
Why the differing findings? It may be because the studies used different criteria to define the stages of reproduction, such that the early postmenopausal group in the Rochester study may have been more similar to the SWAN late perimenopause group.
What you can do
While it’s not uncommon to feel like your brain isn’t functioning as well as it should during the transition to menopause, the effects appear to be temporary and may improve once a new state of physical equilibrium is reached. In the meantime, there are things you can do to guard against changes in your memory and cognitive function. Your best bets for protection:
• Take care of your heart health as you age. The older you are—after about age 55 for women—the greater your risk of developing coronary heart disease.
If you also have other risk factors for coronary heart disease, such as high blood pressure, abnormal cholesterol levels, or diabetes, evidence suggests that you may also be at increased risk for experiencing adverse cognitive effects. Declining estrogen levels may be a factor in CHD as well. Estrogen is believed to help keep blood vessels flexible, allowing them to relax and expand to accommodate blood flow.
• Exercise regularly. The American Heart Association recommends 30 minutes or more of moderate intensity aerobic activity at least five days per week or at least 25 minutes of vigorous aerobic activity three days a week or more (or a combination).
• Keep your blood pressure under control; 120/80 mm Hg is the goal for most people.
• Consume a healthy diet consisting mostly of fruits, vegetables, grains (especially whole grains), and proteins, such as salmon and other types of omega-3-rich fish, beans, and nuts.
If your menopausal symptoms are bothersome, ask your doctor about HT. Although HT is no longer routinely recommended, some studies suggest that there may be a critical “window” during which it may offer some neuroprotective effects.
And continue to challenge your brain with mental workouts; for example, reading, games, or puzzles. And use lists, calendars, and other devices to ease the burden on your overtaxed mind.
Of course, if you regularly experience worrisome memory glitches and they’re making you anxious, or you have a family history of Alzheimer’s or another form of dementia, it’s wise to seek a professional evaluation.