Environmental Enrichment Fights Alzheimer's Disease

Professor Daniel Geschwind describes resaerch that shows that keeping the brain active can build up resistance to Alzheimer's disease.

Alzheimer’s disease is a very complex disorder. When we compare it to other disorders, we know more about it genetically than most of the other complex disorders. So there is a lot evidence that specific genes can cause Alzheimer’s disease. Along with this, people have found that there are gene-environment interactions, so environment may play a cause. There is this idea that an enriched environment, more learning, more reading, may lead to preservation of cognitive function. What people have done now is taken mutations that cause Alzheimer’s in people, and put them into mice, and shown if you exercise those mice or put them in a better environment with more colorful toys, etc., those mice do better, live longer, and when they do get Alzheimer’s-like pathology, it’s much later and less severe than in the mice who don’t have that environment. So that provided some experimental evidence that exercise or enrichment, can certainly in an animal model stave off the ravages of Alzheimer’s disease. In people, we do what are called epidemiologic studies, that is we look at large populations of people and follow them over time. And there is some interesting evidence there where they’ve looked at nuns and found that the nuns who read more were much less likely to get Alzheimer’s disease and when they did it was later, etc. So, that was pretty interesting. The question is, is it actually preventing Alzheimer’s disease, or just leading to a higher cognitive reserve? In those patients you could say that those who read and were more active were just predisposed to begin with to read and be more active and it’s those that are less active that are going to get Alzheimer’s disease. So when you do an epidemiologic study, you can’t assess causality. You only see the association. In the animal study though, you can assess causality by changing and manipulating variables in different groups. So the animal study tacked onto the human study, suggests that actually environment can change your brain and change it to be more resistant potentially. So it’s very exciting. I urge everybody to stay very active, read a lot, do all your math and all your homework and you’ll live a long and happy life.