Regular physical activity can cut your risk of dementia

 

Regular physical activity is one of the best things you can do to reduce your risk of developing dementia.

People between the ages of 40 and 79 who took 9,826 steps per day were 50% less likely to develop dementia within seven years, the study, published in JAMA Neurology, found.

Furthermore, people who walked with “purpose” – at a pace over 40 steps a minute – were able to cut their risk of dementia by 57% with just 6,315 steps a day.

And even people who walked approximately 3,800 steps a day at any speed cut their risk of dementia by 25%, the study found.

Thus you will need to walk between 3,800 and 9,800 steps each day to reduce the risk of mental decline.

But intensity of stepping does matter - over and above volume.

The largest reduction in dementia risk – 62% – was achieved by people who walked at a very brisk pace of 112 steps per minute for 30 minutes a day. Prior research has labeled 100 steps a minute (2.7 miles per hour) as a “brisk” or moderate level of intensity.

“While 112 steps/min is a rather brisk cadence, ’112’ is conceivably a much more tractable and less intimidating number for most individuals, especially if they have been physically inactive or underactive,” wrote Alzheimer’s researchers Ozioma Okonkwo and Elizabeth Planalp (Okonkwo is an associate professor in the department of medicine at the Wisconsin Alzheimer’s Disease Research Center at the University of Wisconsin–Madison; Planalp is a research scientist in Okonkwo’s lab).

Hence, individuals looking to reduce their risk of dementia should focus on their walking pace over their walked distance.

While agreeing that the findings cannot be interpreted as a direct cause and effect between walking and a lower risk of dementia, and the results may not be generalizable to older populations, “the mounting evidence in support of the benefits of physical activity for maintaining optimal brain health can no longer be disregarded,” wrote Okonkwo and Planalp.

Besides walking, even regularly doing household chores could lower risk by 21% while daily visits with family and friends lowered the risk of dementia by 15%, when compared with people who were less engaged.

Another study found that exercise may slow dementia in active older people whose brains already showed signs of plaques, tangles and other hallmarks of Alzheimer’s and other cognitive diseases.

That study found exercise boosts levels of a protein known to strengthen communication between brain cells via synapses, which may be a key factor in keeping dementia at bay.

“Dementia is preventable to a great extent,” said del Pozo Cruz, an adjunct associate professor at the University of Southern Denmark in Odense, Denmark, and senior researcher in health sciences for the University of Cadiz in Spain.

“Physical activity as well as other lifestyle behaviors such lack of alcohol and smoking, maintaining a healthy diet and weight and sleep can put you on the right track to avoid dementia.”

For Alzheimer's disease specifically, regular exercise can reduce the risk by 45%.

Aside from dementia, many studies have shown a clear link between physical activity levels and thinking skills. These studies suggest exercise might be an effective way to reduce cognitive decline in later life. Several studies have also shown people who were physically active at age 70 experienced less brain shrinkage over three years than those who were not.

There are two main types of physical activity – aerobic activity and strength-building activity. Each type will keep you fit in different ways. Doing a combination of these activities will help you to reduce the risk of dementia.

Aerobic activity helps to keep your heart, lungs and blood circulation healthy – and this is good for brain health.

On the other hand, strength-building activity works your major muscles (legs, back, stomach, shoulders, arms). This type of activity also helps you to control the level of sugars in your blood and reduce your risk of diabetes, which is a risk factor for dementia. Ideally you should do strength-building activities on at least two or more days each week.

Exercise has also shown positive effects on the brains of healthy older people. In one trial, a year of doing regular exercise resulted in a small increase in the size of the hippocampus (the key brain area involved in memory). This is the same as reversing one to two years of age-related shrinkage.