Skip the elevator: A 15-minute walk can help your brain fight off Alzheimer’s

GÖTTINGEN, Germany — Older people can stave off Alzheimer’s disease with a daily 15-minute walk or other physical activities, according to new research.

Researchers in Germany say moderate physical activity boosts all areas of the brain, especially those involved in memory. Staying active also benefits people over 70 the most. They see the biggest increase in grey matter, compared to their “couch potato” peers.

“In principle, this is very good news – especially for those who are reluctant to exercise,” says study author Dr. Ahmad Aziz from the German Center for Neurodegenerative Diseases in a media release.

“Our study results indicate that even small behavioral changes, such as walking 15 minutes a day or taking the stairs instead of the elevator, may have a substantial positive effect on the brain and potentially counteract age-related loss of brain matter and the development of neurodegenerative diseases. In particular, older adults can already profit from modest increases of low intensity physical activity.”

The number of dementia cases worldwide will triple to around 150 million by 2050, according to estimates. With no cure in sight, there is an increasing focus on protective lifestyles. Exercise is known to be good for both the mind and body. However, this study is the first to identify exactly how and where it affects the brain.

“In previous research, the brain was usually considered as a whole,” says Fabienne Fox, neuroscientist and lead author of the study. “Our goal was to take a more detailed look at the brain and find out which regions of the brain physical activity impacts most.”

Walking can boost neuron activity

The study found physical activity increases neurons across the organ, in particular the hippocampus, which controls memory. The findings come from a review of 2,550 individuals living around Bonn. The 30 to 94-year-olds wore an accelerometer on their upper thigh for seven days.

They also underwent MRI (magnetic resonance imaging) scans that measured brain volume and thickness of the outer layer, or cortex.

“We were able to show that physical activity had a noticeable effect on almost all brain regions investigated. Generally, we can say that the higher and more intense the physical activity, the larger the brain regions were, either with regard to volume or cortical thickness,” Fox adds.

“In particular, we observed this in the hippocampus, which is considered the control center of memory. Larger brain volumes provide better protection against neurodegeneration than smaller ones.”

However, researchers say the dimensions of the brain regions did not increase linearly with physical activity. The largest, almost sudden, changes were in moderately physically active older adults compared to their sedentary peers. Young and somewhat athletic participants who usually engaged in moderate to intense physical activity also had relatively high brain volumes.

‘Even modest physical activity can help’

In even more active seniors, these regions were slightly larger. The more active, the greater the effect. However, at high levels of physical activity the improvements tended to level off. Researchers also searched gene databases to characterize areas that benefited most from physical activity.

“Mainly, these were genes that are essential for the functioning of mitochondria, the power plants of our cells,” Fox continues.

It means there are many of these tiny chemical factories in these regions. They provide our body with energy, for which they need a lot of oxygen.

“Compared to other brain regions, this requires increased blood flow. This is ensured particularly well during physical activity, which could explain why these brain regions benefit from exercise,” says Ahmad Aziz.

Further analysis showed there is a large overlap between genes switched on by exercise and those impacted by Alzheimer’s, Parkinson’s, or Huntington’s disease. It sheds fresh light on why physical activity reduces the risk of neurodegenerative diseases.

“With our study, we were able to characterize brain regions that benefit from physical activity to an unprecedented level of detail,” Aziz explains. “We hope our results will provide important leads for further research.”

“With our results, we want to provide a further impetus to become more physically active – to promote brain health and prevent neurodegenerative diseases,” Fox concludes. “Even modest physical activity can help. Thus, it’s just a small effort – but with a big impact.”

The study is published in the journal Neurology.

South West News Service writer Mark Waghorn contributed to this report.

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