Dr. Yaakov Stern is the Division Leader of the Cognitive Neuroscience Division of the Sergievsky Center at the College of Physicians and Surgeons of Columbia University, New York. He is one of the leading proponents of the Cognitive Reserve theory.
Alvaro Fernandez (AF): Dear Dr. Stern, it is a pleasure to have you here. Let me first ask you this: the implications of your research are pretty astounding, presenting major implications across sectors and age groups. What has been the most unexpected reaction so far?
Yaakov Stern (YS): well…I was pretty surprised when, years ago, a reporter from Seventeen magazine requested an interview. I was really curious to learn why she felt that her readers would be interested in studies about dementia. What she told me showed a deep understanding and insight: she wanted to motivate children to stay in school. She understood that early social interventions could be very powerful for building reserve and preventing dementia.
AF: That’s great…so let’s now fast forward, say, 60 years from our high-school years, and suppose that persons A and B both technically have Alzheimer’s (plaques and tangles appear in the brain), but only A is showing the disease symptoms. What may explain this discrepancy?
YS: Individuals who lead mentally stimulating lives, through education, occupation and leisure activities, have reduced risk of developing Alzheimer’s. Studies suggest that they have 35-40% less risk of manifesting the disease. The pathology will still occur, but they are able to cope with it better. Some won’t ever be diagnosed with Alzheimer’s because they don’t present any symptoms. In studies that follow healthy elders over time and then get autopsies, up to 20% of people who did not present any significant problem in the daily lives have full blown Alzheimer’s pathology in their brains.
AF: What exactly may be going on in the brain that provides that level of protection?
YS: There are two ideas that are complementary. One idea postulates that some individuals have a greater number of neurons and synapses, and that somehow those extra structures provide a level of protection. The other theory emphasizes the building of new capabilities, how people can perform tasks better through practice, and how these skills become so well learned that they are not too easy to unlearn.
AF: OK, so our goal is to build that Reserve of neurons, synapses, and skills. How can we do that?
YS: In summary, we could say engaging in activities. In our research almost all activities are seen to contribute to reserve. Some have challenging levels of cognitive complexity, and some have interpersonal or physical demands. In animal studies, exposure to an enriched environment or increased physical activity result in increased neurogenesis (the creation of new neurons). You can get that stimulation through education and/ or your occupation. There is clear research showing how those two elements reduce the risk. Now, what is very exciting is that, no matter one’s age, education and occupation, our level of participation in leisure activities has a significant and cumulative effect. A key message here is that different activities have independent, synergistic, contributions, which means the more things you do and the earlier you start, the better. But you are never stuck: better late than never.
AF: Can you give us some examples of those leisure activities that seem to have the most positive effects?
YS: For our 2001 study we evaluated the effect of 13 activities, combining intellectual, physical, and social elements. Some of the activities with the most effect were reading, visiting friends or relatives, going to movies or restaurants, and walking for pleasure or going on an excursion. As you can see, a variety. We saw that the group with high level of leisure activities presented 38% less risk (controlling for other factors) of developing Alzheimer’s symptoms. And that, for each additional type of activity, the risk got reduced by 8%. Physical exercise, by itself, also has a very beneficial impact. So, we need both mental and physical exercise. The not-so-good news is that, as of today, there no clear recipe for success. More research is needed before we prepare a systematic set of interventions that can help maximize our protection.
AF: What do you think of the relatively recent appearance of so many computer-based cognitive training programs?
YS: At least from the point of view of Alzheimer’s, we don’t know if learning a new language is more beneficial than learning a new musical instrument or using a computer-based program. It is too early to tell the long-term effects. Right now, the most we can say is that those who lead mentally stimulating lives, through education, occupation and leisure activities seem to have the least risk of developing Alzheimer’s Disease.
Copyright (c) 2007 SharpBrains