Get Out and Walk! Your Brain Will Thank You
How walking can boost your brain power
Posted February 15, 2011
In one condition, 60 healthy older volunteers were assigned to regimen of moderately intense aerobic exercise in which they walked around a track for 40 minutes at a time, 3 days a week. They were compared with a group assigned to stretching, yoga, and resistance training with bands. One year later, the two groups were compared on their aerobic capacity, the size of their hippocampus (the brain's short-term memory center), and spatial memory (the ability to remember patterns). Aerobic power increased only in the aerobic exercise group, a finding seen in virtually all studies of aging and exercise. However, remarkably, the volume of the hippocampus increased only in the aerobic group. The hippocampus is not known for increasing at any point in later life. If anything, the hippocampus tends to get smaller. Alzheimer's disease ravages the hippocampus, which is one of the main causes of memory symptoms. The ability to stop the hippocampus from shrinking in and of itself through moderate exercise is a pretty significant result.
The findings on memory were a bit more complicated. The walking group did improve in their spatial memory performance over the one-year period of the study, but so did the stretching group. However, only the participants in the walking group showed a connection between increasing their hippocampal volume and increasing their memory scores. In fact, though not reported in the paper, there was no relationship between hippocampal changes and memory improvement. This is perhaps the crux of the study's results. The important point is that looking at the average doesn't always tell you the whole story.
Yet, the fact remains that the stretchers did improve their memory over the course of the study, just not their brains.
In an interview with me last week, co-author Art Kramer, pioneer in the aerobic exercise-brain aging field, stated his displeasure about this erroneous statement in no uncertain terms: "That's a distortion." It's no wonder. the New York Times had not even talked with him or Erickson to check the accuracy of their reporting.
The moral of the story is that, when possible, read the source yourself, and don't just rely on media sound bites. It's especially important when you are thinking of making major life changes on the basis of a science story that you read online or in the paper.
I actually think that the ease of walking probably negated some of the study's more powerful effects. It's doubtful that any of the people in the stretching group actually refrained from walking for an entire year. As a result, some of the benefits of exercise leaked out into the supposed "control" group.
Returning to the study's findings, they are still exciting and important. Though walking isn't necessarily the easiest exercise for everyone , it beats many of the alternatives. Walking is relatively easy for most people to build into their daily routines. It's a tantalizing thought to imagine that all you have to do is walk and you'll beat the dreaded effects of aging on your mind. Walking is also much cheaper and far less risky than taking powerful medications such as Aricept to prevent or slow Alzheimer's disease.
Erickson and his team have drawn a new line in the sand in the battle against preventable cognitive declines. Their work reinforces the notion that our brains are "plastic," meaning that they can grow and adapt to our life's demands. Back in the bad old days when study after study documented the brain's inevitable decline with age, researchers were convinced that aging could be described by the ugly term "neuronal fallout model." One of the first research teams in the field to demonstrate plasticity was Steven Buell and Paul Coleman (then at the University of Rochester). Starting back in the late 1970s, they showed that most of those fallout model studies were flawed. They compared autopsy findings from the brains of "healthy" (non-demented) with the brains of people who had dementia. The brains from the healthy subjects showed signs of continued growth of new synapses. Though people did lose neurons as they grew older, those neurons that remained were capable of sprouting new connections, particularly if the brain's owners were mentally active.
1. Use it so you don't lose it. This well-worn phrase continues to be true. Your brain is a "mental muscle" that needs exercise to grow and adapt. The more you activate your mind, the more it will respond to the demands you place upon it.
2. Get up and start moving. We now know that a healthy body creates the conditions for a healthy mind. Many systems of the body, from the cardiovascular to the immune system, benefit from regular workouts. It's no wonder that the brain benefits as well.
3. Don't make excuses. Even if you can't walk for 40 minutes at a time, walk for 10. These effects, as the authors stated were "dose dependent," meaning that something is better than nothing.
4. Look for new ways to stimulate your mind. Creative new pursuits can build new connections in your brain.
5. Be wary of headlines about research. Form your own conclusions about research studies by doing your own online detective work, especially when it comes to protecting your brain's health.
It's never too early to start getting your brain in shape. The good news is that it's never too late.
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Copyright Susan Krauss Whitbourne, Ph.D. 2011