My Mind — Where Did It Go?
If you're nearing age fifty and you haven't yet begun to experience periodic memory lapses, consider yourself lucky. The busier and more stressful life becomes, the easier it is to misplace items, forget an associate's name, lose track of the point you were about to make, and remember the title of that movie. As one fifty-something friend once said, “It takes three middle-aged people to tell any one story.” Multiple events challenge the memory at middle age and many of them still are not fully understood. Though many women wonder if they're showing the first signs of Alzheimer's, the vast majority of memory loss problems are natural — and sometimes transient — responses to the effects of age, menopausal hormone changes, stress, and a busy, changing life.
Many women report an increase in forgetfulness and memory loss, as well as decreased mental clarity, during perimenopause. Because hormones tend to fluctuate dramatically during this period, estrogen deficiency used to be the culprit most often blamed for changes in memory functions. But studies such as the Seattle Midlife Women's Health Study, conducted by the University of Washington in 2000, dispute that notion. In that study, researchers found that neither the age nor the perimenopausal stage of the women studied were linked to any diminishment of the women's mental functions. In fact, the study found that younger women and women undergoing hormone therapy were more likely than midlife women to report problems with memory loss.
Alzheimer's disease is more common in women than in men, and it strikes women at an earlier age. The symptoms, which include memory loss, diminished language and motor skills, and an inability to recognize people or objects, appear gradually and worsen with age. If you are increasingly dependent on others for your decisions, or are losing the ability to do everyday tasks, you can ask your health care provider to perform diagnostic tests to see if you have early Alzheimer's disease.
The Seattle study found that physical health, emotional factors, and stress accounted for almost half of the memory loss noted in participants. Depression and high levels of stress played a key role in short-term memory degradation. Among participants in the study, only 24 percent of memory loss was attributed to the physical effects of aging.
Most medical and scientific authorities agree that age results in subtle changes in anyone's ability to think clearly and quickly, but that doesn't link memory loss to menopause; causes for these mental lapses are tied more closely to the brain than the ovaries. First, the human brain shrinks after age fifty, due to a loss of water content. That shrinkage doesn't necessarily impair memory, of course, but a loss of volume in the frontal lobes can. Some neuroscientists say that the frontal lobes can shrink as much as 30 percent between the ages of fifty and ninety. Because the frontal lobes are so important to complex thinking, losses in that area of the brain can impair your ability to reason things out, maintain attention span, multitask, and use your best judgment.
Although you don't have to fear that your brain will shrink up like a walnut when you hit fifty, real physical changes can begin at this time, and you may begin to feel their impact on your short-term memory, attention span, and other thinking processes. Chapter 18 offers some simple techniques for keeping your mental edge as you move toward and through menopause.
And the brain's hippocampus can lose some of its capabilities with age, too. This part of the brain is responsible for creating, storing, and retrieving memory, and scientists now think it can lose a portion of those abilities with age. A slowing of mental processes accounts for many of the cognitive changes that you perceive with age. In other words, the information is all there and your brain can retrieve it — that retrieval process just takes longer than it used to. Metabolic changes and a diminished number of brain signal transmitters (called dendrites) on your brain cells (neurons) contribute to the slowdown.
The inability to focus is also common in perimenopause, and may be due to normal aging of the brain or may be a temporary shift as your hormones change. There are several causes of decreased concentration, any or all of which may explain why you keep reading that paragraph over and over and can't seem to focus on the story you are reading.
Concentration, like memory, is a cognitive task that relies on brain chemicals and brain structures that are sensitive to hormonal changes. If you have a history of premenstrual syndrome (PMS) and found that you could not concentrate as well just before your period, you may be more prone to this symptom in menopause. As estrogen decreases, some women have fewer of the neurotransmitters such as serotonin to carry messages in the brain. And normal aging of the brain means that in middle age people become less able to turn off the “daydreaming” area of the brain, making it easier to be distracted and harder to pay attention.
As frustrating as it is to lose concentration, the news is not all bad. As your body adjusts to new levels of hormones, some of your ability to concentrate will return. And research is discovering that the human brain is much more adaptable than previously thought. When we lose abilities in one section of the brain, we seem to be able to rebuild those abilities using another part of the brain. The secret seems to lie, in part, with keeping your body and attitude healthy so that you have the right building materials to make those changes. More on this in Chapter 18.
The level of stress hormones in your body can seriously alter your memory and concentration. Other factors such as loss of sleep, alcohol use, and vitamin B12 deficiency — all common during this life stage — are more common reasons for cognitive trouble than low estrogen.