Memory and the Brain

This article was first printed in Mind Over Menopause: The Complete Mind/Body Approach to Coping with Menopause, by Leslee Kagan, M.S., N.P., Bruce Kessel, M.D., and Herbert Benson, M.D., published by Free Press, 2004. For more information or to order, please go to click here.)

All other things we study as neuroscientists are objective, public measurements of the organ we call the brain. The mind, even though it’s produced by the brain and closely linked to it, is accessible only to its owner.

—DR. ANTONIO DAMASIO, NEUROLOGIST

If you’ve heard reports that lowered estrogen levels are linked to Alzheimer’s disease (AD) and you’ve begun the process of self-diagnosis, you’re not alone. Many women are a bit baffled and disconcerted by the suggestion that menopause affects memory. However, issues of memory apply to both men and women and are far too complex to be explained by gender specific hormones.

Alzheimer’s disease isn’t just trouble remembering. It is a degenerative brain disease characterized by continual loss of nerve cells in areas of the brain crucial to memory and other mental functions. Women appear to suffer Alzheimer’s disease at a somewhat higher rate than men do. It’s not at all clear, though, that the reason has to do with physical changes after menopause. One in ten people over the age of sixty-five and nearly half of those over age eighty-five have Alzheimer’s disease. There are many confusing aspects of research on Alzheimer’s. Many of the studies are either done on animals or are observational studies, which as we’ve seen, have limitations. Data from a number of studies suggest that estrogen has beneficial effects on brain neurons and may improve learning and memory. Some observational studies in women suggest that estrogen used for at least ten years might delay or prevent Alzheimer’s disease. However, in women with established Alzheimer’s disease, randomized clinical trials have shown that estrogen is not effective as a treatment. Furthermore, combined hormone therapy (estrogen and progesterone) may actually increase the risk of dementia.

In another surprising turn of events, the Women’s Health Initiative Memory Study (WHIMS) revealed that combined hormone therapy actually increased the likelihood of developing what was termed “probable dementia.” Dementia involves the deterioration of intellectual faculties like memory and other cognitive abilities. It can be difficult to diagnose and, in the case of WHIMS, required researchers to use a cognitive questionnaire and enlist family members of the participants. The study set out to determine whether estrogen supplementation (either estrogen alone or estrogen plus progestin) reduces the risk of dementia in healthy women. More than 4,500 women over the age of sixty-five took part. These women took either estrogen (Premarin), estrogen plus progestin (Prempro), or a placebo.

Though the estrogen/progestin arm of the WHI was called off early due to concerns about an increased risk for breast cancer, researchers were able to use the early data to better understand combined hormone therapy and memory. The data showed that the risk of probable dementia for women in the estrogen plus progestin group was twice that of women in the placebo group. What’s more, the evidence of increased risk was noticed as early as one year after the study started. And the differences persisted over five years of follow-up.

The results were considered unexpected and in stark contrast to earlier studies on the effects of hormone therapy on Alzheimer’s disease and dementia. However, it is important to note that while the increased relative risk was twofold, the absolute risk was relatively small—resulting in an additional 23 cases of dementia per 10,000 women per year. The early results of WHIMS are further evidence that hormone therapy should not be considered as a preventive treatment for memory problems. As of this writing, the estrogen-only arm of the Women’s Health Initiative continues and is expected to provide additional information about the effects of supplementing estrogen only. There are also questions about the timing of hormone therapy. Does starting HT at a younger age make a difference? All the women in the study were age sixty-five or older. Despite some unknowns, in light of the increased risk of breast cancer and heart attack reported, the WHIMS estrogen plus progestin data reinforce the idea that the risks of long-term combined hormone therapy outweigh the benefits.

Mind/body and memory

For women at menopause, issues of memory and clarity of thinking cannot be separated from contributing psychological and social factors. Stress, sleep, and mood, as well as hormones, all play a role. Just as there are things you can do to preserve your health, there are things you can do to protect your memory. What’s great about these strategies is that many of them are good for your overall health.

Get a good night’s sleep: People who don’t sleep well at night tend to be more forgetful than people who sleep soundly. Try to shoot for a minimum of six hours a night.

Use your mind/body skills: Months and months of insomnia were the most compelling reason for Karen to join our program. She had begun waking up at three or four in the morning feeling warm and uncomfortable, with racing thoughts and heart palpitations. Her inability to get back to sleep triggered anxiety and fear about “never being able to sleep restfully again.” Those thoughts worsened the insomnia.

Karen recalled sitting at her dining room table trying to write checks, but feeling as though she just couldn’t do this task that she had done so many times. “I had always prided myself on having a good, sharp memory. All of a sudden it felt like things were out of focus and it was hard to concentrate. It was hard to move my mind from one thing to another and juggling things became very stressful. It was scary actually ...I felt like my brain wasn’t working properly and that generated a tremendous amount of mental stress.”

For Karen, mind/body techniques were extremely helpful. Developing a regular relaxation response practice helped her to quiet her mind and alleviate much of the mental stress she felt. This, in turn, improved her sleep. “The breathing and relaxation techniques calmed my body, but also my mind. It slowed my thinking, I felt calmer, my mind was quieter so I could focus better.” Mindfulness is another skill she, and others, find extremely helpful. “Mindfulness counteracted my sense of not being able to focus. It slows you down and makes you focus on one thing . . . staying in the moment. It took a few weeks, but I started to feel better and eventually it all went away.”

Here are some ways many of our patients quiet their minds and get a more restful night’s sleep:

• Develop a regular practice of eliciting the RR.
• Practice mindfulness: Do one thing at a time, and do it with your full mental and sensory attention.
• Practice self-nurture: When you feel rested, renewed, and energized you will be better able to focus/concentrate.
• Watch your thoughts: Reframe those that increase worry, anxiety, and stress and exacerbate insomnia.

Exercise: People who stay mentally sharp in their seventies and eighties also tend to get regular vigorous exercise. First of all, it’s good for the lungs, and people whose memories and mental acuity remain strong in old age characteristically have good lung function, which is essential to delivering oxygen-rich blood to the brain. Second, exercise helps reduce the risk for diabetes and hypertension, illnesses that can be contributors to memory loss. And finally, animal research has shown that exercise increases the level of neurotrophins, substances that nourish brain cells and help protect them against damage from stroke and other causes.

“Exercise” the brain: Over time, people who don’t challenge their minds have a greater degree of memory decline than do those who stay mentally active. Learn something new every day. Develop a lifelong habit of learning and challenging yourself mentally by doing things like reading, playing chess, doing crossword puzzles, or acquiring new skills. This mental activity is thought to help keep the brain in shape. So keep your brain busy!

Eat a healthy diet: A diet rich in antioxidants helps to neutralize free radicals, which can contribute to the aging of cells throughout the body, including the brain.

Protecting your memory

The effort to preserve memory as we age is a prime area of research. But reports about research should not be taken out of context. Discuss any concerns with your clinician. Many conditions can trigger memory loss. So can some medications. If you suspect your memory lapses are not normal, a knowledgeable clinician is your best resource for evaluation and for the most up-to-date information in this rapidly evolving field.

Alzheimer’s disease prevention: As mentioned, Women’s Health Initiative data show combined hormone therapy (estrogen plus progestin) is found to increase the risk of probable dementia in women over the age of 65. So, hormone therapy should not be used to protect against Alzheimer’s disease. Although an in-depth discussion of treatment options for Alzheimer’s is beyond the scope of this book, there is a class of drugs approved for treating this disease. They’re called acetylcholinesterase inhibitors (or AchE inhibitors), for example, donepezil (Aricept). Research on prevention and treatment continues, and progress is being made. For example, in October 2003, the FDA approved the drug memantine (Namenda). It is used for the treatment of moderate to severe Alzheimer’s disease and is thought to work by blocking the action of the chemical glutamate. Several other medications under investigation look promising for prevention. These include other AchE inhibitors, anti-inflammatory agents, and antioxidants.

“Memory” supplements: Many “nutritional supplements” are marketed as effective alternative “therapies” for improving memory and many of our patients ask about these. Many have little or no solid evidence to support their use and limited data on effectiveness or safety. One of the most common is ginkgo biloba. A few studies have found a benefit from this herb, but others have not. So, additional research is needed to support the use of this supplement for Alzheimer’s disease. If you take any blood-thinning medications (warfarin, aspirin, ibuprofen, and others), talk with your clinician before taking ginkgo biloba. There have been reports of some bleeding within the brain when used with such medications. And it should definitely not be used prior to surgery.

From: Mind Over Menopause: The Complete Mind/Body Approach to Coping with Menopause, by Leslee Kagan, M.S., N.P., Bruce Kessel, M.D., and Herbert Benson, M.D., published by Free Press, 2004.