Natalie Staats Reiss, Ph.D. is a licensed Psychologist in the state of Ohio (License #6083). She received her Ph.D. in Clinical Psychology from ...Read More
In my clinical work with older adults, I was often asked "What can I do to protect myself from Alzheimer’s?" This always prompted a discussion of the risk factors (e.g., age, family history of the disorder, genetic makeup, high blood pressure, and high cholesterol) for this devastating disease that affects approximately 4.5 million people in the United States. My recommendations to my clients were: eat a healthy diet (i.e., lots of fruits, vegetables and whole grains, and low amounts of saturated fats), exercise your body and brain, and cultivate a close network of friends and confidants.
I remember one gentleman in particular who wasn’t satisfied with my standard answer. He countered with "But what is MOST important?" At the time, I told him that the science wasn’t out there to enable me to answer that question with any level of confidence. In other words, I used polite "doctorspeak" for "We don’t know."
Based on new research published in the journal Neurobiology of Learning and Memory (Vol 88, Issue 3, Pages 277-294), I can better answer that gentleman’s question. This study compared the long-term effects of social, physical and cognitive (thinking) activity in mice, and showed that the latter (cognitive activity) was the best protector against developing Alzheimer’s disease (AD).
I am sure some of you are thinking– why should I care about mice with AD?! Let me detour a minute and talk about research on AD. Scientists are working around the clock to find more effective treatments and ways to prevent this disease from occurring in the first place. Many of the studies, particularly those focused on prevention (decreasing risk) are impractical to conduct with humans for several reasons: 1) we don’t know exactly who is going to develop AD, 2) the definitive way to diagnose AD is with autopsy, and 3) it is hard to isolate specific protective factors in humans.
Let me expand each of these points. Right now, there is no test that we can give someone that will definitely tell us whether or not they will develop Alzheimer’s disease. AD begins in the brain several decades before any symptoms show up; and currently, the only way to make sure a person truly has AD is to examine brain tissue collected after they have died. People who are diagnosed with AD live from 3 to 10 years. To study a large group of people who we suspect might develop AD (but don’t know for sure) to determine which factors protected them against developing the disease might take up to 30 years.
Also, we can’t take a group of people who might develop Alzheimer’s and run a tightly-controlled study of which factors are most protective. In other words, we can’t divide people into groups and require that certain people only engage in social activity, but no physical activity. Similarly, we can’t ask another group to only use cognitive activities and refrain from any social and physical activity. Real-world studies with humans are often messy. Too many factors are intertwined and out of our control; therefore, that limits our scientific ability to make firm conclusions and recommendations.
To counter these problems, researchers use special "Alzheimer’s mice" that have been bred with genetic mutations. These mice have too much of a specific type of protein called amyloid precursor protein (or APP) that creates an excess of another substance, beta-amyloid. In both humans and mice, an excess of beta-amyloid is responsible (at least partly) for causing the symptoms of AD.
These AD mice don’t live very long, so it is easier for researchers to follow them across their entire lifespan. Also, scientists can use MRI (magnetic resonance imaging) in order to view subtle brain changes (i.e., the plaques created by beta-amyloid) in these mice while they are alive because their brains are significantly smaller than human brains. Finally, scientists can tightly control the environments of these mice, making sure that only the variable of interest is changed across different groups, which strengthens their ability to draw conclusions.
Back to the current study. Researchers took young adult AD mice and assigned them to one of 4 groups: 1) high social activity 2) high physical activity 3) high cognitive activity 4) control (no special activity). Only the mice in group 3 who were given a lifelong high level of cognitive activity were protected against memory impairment. Mice in group 3 performed as well as normal mice that do not go on to develop Alzheimer’s disease. In addition, brain levels of beta-amyloid were substantially reduced only in group 3 (high levels of this protein remained in groups 1 and 2). Finally, group 3 was the only one that experienced increased connections between brain cells during their development.
This study suggests that cognitive activity may be more important than social or physical activity for protecting against or delaying Alzheimer’s disease. The take home message? Start "exercising" your brain now to help prevent developing Alzheimer’s disease later.
Here are some ways to "exercise" your brain:
- Learn new things in your workplace
- Limit the amount of time you spend watching non-educational TV
- Take a course or class, or attend a lecture
- Read books and newspapers
- Have intellectually-stimulating conversations
- Play puzzle games (e.g., crosswords, Sudoko)
- Go to museums