Why exercise protects your brain against dementia

Time and time again, research shows that regular exercise will lengthen your life expectancy and keep you fitter, happier and healthier as you age.

Another reason to make exercise a priority is the promising amount of research that points to it as a way to fight dementia and keep our minds sharp well into old age.

“Converging evidence suggests exercise benefits brain function and cognition across the mammalian lifespan, which may translate into reduced risk for Alzheimer’s

More research is needed to understand exactly why this is, but it seems largely to do with the hippocampus, part of the brain which is vital for creating new memories.

The hippocampus shrinks in the final years of our lives, and is the part of the brain first and worst affected by Alzheimer’s. But studies have found the hippocampus responds quickly and positively to exercise.

A 2011 study of 120 elderly people published in scientific journal PNAS found that aerobic exercise grew the size of the anterior hippocampus, and led to improvements in memory.

The researchers say hippocampal volume increased by 2 percent, reversing age-related loss in volume by at least one to two years.

A 2011 study found that children who took part in aerobic fitness regularly were better at “relational binding” (like recalling the name of a person you met recently and where you met them) than less active kids.

A study of adult rats found that running increased the growth of new neurons in the hippocampus compared with their sedentary rat counterparts.

One study on mice found the neural benefits of physical exercise lasted up to two weeks after the session.

And another study of 1740 men and women aged 65 or older with no cognitive impairment at the beginning of the research found that six years later, incidence of Alzheimer’s was higher in those that exercised less than three times per week than those who exercised more frequently.

Aside from the hippocampus research, exercise will also reduce your chances of developing dementia because it decreases some key dementia risk factors including heart disease, stroke, high blood pressure, type 2 diabetes and obesity.

Art Kramer, director of the Beckman Institute for Advanced Science and Technology and a Professor of Psychology at the University of Illinois in the US, is about to begin a multimillion dollar study into this area of research.

“Exercise doesn’t just maintain cognitive ability, but actually improves it,” he told Coach. “In randomised control trials in sedentary older adults you find they improve memory, problem solving and a variety of other things when exercise is introduced.”

Kramer said while it’s exciting for older members of the population, parents should encourage their children to set up consistent exercise habits for life.

“Some of the research will focus on working with kids in after school exercise programs, because kids are becoming increasingly sedentary, increasingly obese.”

Alzheimer’s Australia recommends at least 30 minutes of aerobic exercise, such as brisk walking, dancing, jogging, bicycling or swimming, on most days of the week.