Researchers found that when older men and women walked for six months, their white matter and cognitive skills got better, but that didn’t happen when they danced or did stretching exercises. A new study on the effects of walking and dancing on brain health found that regular exercise can repair and renew the white matter in our brains, making it easier for us to think and remember as we get older. It shows that more physical activity changes the structure of white matter in the brain. White matter helps connect brain cells and gives them structure. But white matter is more likely to shrink and show signs of wear and tear in people who don’t move around much.
What Happens to Our Brains
The results show how our brains change depending on how we live and what we do. The idea that adults’ brains can change is pretty new. Most scientists started to question the idea that an adult brain is physically fixed in the late 1990s. Most people thought that our brains had all the cells they needed already. If this were true, as we got older, our brains would get weaker and less able to do things.
Thanks to scientific progress, that pessimistic prediction had to be changed. Neurogenesis is the process by which some parts of our brains continue to make new neurons well into adulthood. This is shown by complex studies that use special dyes to find new cells. More research showed that physical activity does help make new neurons. For example, when mice run, they make three to four times as many new brain cells as when they just sit around. When people start an exercise routine, their brain size also grows. The main point of this study is that it shows that our brains stay flexible and change over time, especially in response to how we exercise.
Gray matter, which is where the famous small gray cells, or neurons, that make ideas and memories, live, has been the main focus of previous studies of brain plasticity. Less attention has been paid to white matter, which is the wiring of the brain. White matter is made up mostly of fatty axons that connect neurons. It is an important part of keeping a healthy brain. Still, as we get older, it can become more brittle and thinner. It can also get small holes, called “dilapidations,” which can be signs of cognitive decline. People have also been worried about it because they think it is too set in its ways and can’t change much to keep up with the changes in our daily lives.
Agnieszka Burzynska, a neuroscientist and professor of human development at Colorado State University in Fort Collins, thought that researchers were underestimating how important the brain’s white matter was. She says that gray matter is always overlooked and misunderstood because it is “like the ugly stepsister that nobody likes.” She thought, though, that white matter was just as malleable as gray matter and could change on its own once people started moving.
So, she, her graduate student Andrea Mendez Colmenares, and some other coworkers set out to redesign people’s white matter in a new study that was published online in June in NeuroImage. The first thing they did was find about 250 healthy retirees. First, the participants were given a series of tests in the lab to see how well they could think and how fit they were. Then, an advanced magnetic resonance imaging (MRI) scan of their brains was used to check the health and function of their white matter.
The volunteers were then split into two groups. One group was the active control and did a stretching and balance training program three times a week under the supervision of a trainer. One couple also started taking three 40-minute walks a week at a fast pace. The last group started dancing. They got together three times a week to learn and practice group choreography and traditional dances like the waltz and the cha-cha. After six months of training, each group went back to the lab to take the same tests again at the end of the study.
Scientists also found that the bodies and brains of many people had changed in big ways. Like we thought, the people who walked and danced had better aerobic fitness. Also, their white matter looked like it had been cleaned. Their nerve fibers looked bigger on the new scans, and the size of any abnormal tissue had gone down. Memory tests showed that the walkers improved the most after these good changes. However the dancers didn’t show any change.
Those in the control group who hadn’t done aerobic exercise, on the other hand, had worsening white matter health after six months, including thinner and more broken axons and worsening cognitive scores.
Dr. Burzynska says that these results for the exercisers are “quite hopeful.” She says that a few brisk walks a week may be all that’s needed to keep the tissue in good shape and slow or stop memory loss. This is because research shows that white matter stays active and malleable throughout life.
Naturally, the changes to the brain were hard to notice and happened randomly. Dr. Burzynska and her colleagues thought that dancing, which takes more time to learn and practice than walking, would have more benefits for the brain and white matter than walking. But walking worked better, showing that aerobic exercise is the most important thing for keeping white matter healthy. Dr. Burzynska says, “During each session, the dancers spent some time watching the teachers and not moving around much.” That definitely affected how well they did.
The people in the study were all over 60 years old and had only exercised for six months. No one knows if the brains of younger, healthier people would get the same benefits or if long-term aerobic exercise would improve memory and thinking even more. But, as Dr. Burzynska says, the results give us “a compelling reason” to get up and move around to protect our white matter.