Did you know that exercise is not just for muscle fitness? It’s brain food. Moderate exercise like walking is powerful enough to keep your brain healthy, improve memory, reduce the risk of cognitive decline and help you live longer. Better yet, it's free and all you need is a pair of sneakers.
How much should I walk to keep my brain healthy and resilient against Alzheimer's Disease (AD)?
For decades, researchers have studied the population of Ohsaki City, Japan. People who walked an hour a day had a significantly lower rate of dementia than those who did not walk.
For individuals already at risk for cognitive issues, walking is just as beneficial. A study in JAMA Neurology shows that the brains of people with preclinical signs of Alzheimer's benefit from walking about 8,900 steps per day, or about 4.5 miles. This particular study is the first to show that exercise positively affects the brains of people with high levels of beta-amyloid plaque and no outward Alzheimer's symptoms.
What is Beta-amyloid Plaque?
Beta-amyloid plaques are the abnormal proteins that build up in the brain decades before there is any noticeable sign of AD. During this preclinical stage, it is crucial to take precautions to prevent its progression. Walking plays an important role in boosting the brain's ability to support cognitive function and working memory.
Walking and other forms of moderate exercise do this by sparking the process that releases happiness hormones called endorphins. "Walking can increase endorphins, which increases brain-derived neurotrophic factor (BDNF)," says Margaret Apostol, MD, Medical Director, LifeSeasons Medical Clinic. "The BDNF protein aids in the development of neurons that help with cognitive function," she says.
Walking Can Prevent Brain Shrinkage
Another way walking helps the brain is to prevent shrinkage of the hippocampus. This small crescent-shaped organ, which is responsible for forming new memories, learning, and emotions, shrinks as a natural response to aging. But, when older adults moderately exercise, this loss of brain tissue slows down. The hippocampus increases in size by as much as 2%, which seems like a small percentage, but it effectively reverses age-related shrinkage by one-to-two years.
How Can I Get the Most Out of My Walk?
Dr. Apostol suggests walking after meals. "After a meal, blood sugar spikes naturally," she says. "Blood sugar spikes can cause an increase in beta-amyloid plaque in the brain if left unchecked. Walking for 10-20 minutes after eating a meal can help stabilize blood sugars," she says. "The body works hard to break down sugar through the insulin-degrading enzyme (IDE). This enzyme is also necessary to break down beta-amyloid plaque. If blood sugar is high, IDE works hard to stabilize blood sugars and takes away from the job of breaking down amyloid plaque. Walking can help decrease blood sugar and therefore decrease the need for IDE," she says.
Any form of walking – light, moderate, brisk or fast – has benefits. A series of small walks add up to the same benefits as a long walk. One walk is better than none. And, interval walking, with a varied pace, uses 75% more energy than walking the same speed.
Add Nature to Your Walk for a Bigger Brain Boost
Lastly, find time to walk in nature in your neighborhood, a garden or in a park. The Japanese call walking in nature forest bathing (shinrin-yuko) for its unique ability to reduce stress and improve mood, which is always good for brain health.