Newsflash – physical exercise is good for you. Obviously, we all know this and have been given many reasons why lacing up the walking shoes or heading to the gym on a regular basis are beneficial activities.
In past columns I have even mentioned that exercise can also be great for reducing stress and improving mental health by getting those endorphins flowing. It has also been shown to improve memory and mental ability and was theorized to be useful in the maintenance of cognitive functioning as we get older.
Finally, a couple of new studies have shed a bit more light onto the specific ways in which physical exercise may protect our brains from deterioration and possibly even prevent the onset of dementia or Alzheimer’s disease.
Researchers at the University of Pittsburgh have published a couple of studies examining the effects of physical exercise on the brain. One study examined 299 cognitively normal adults with a mean age of 78. At baseline, the volunteers’ exercise levels were assessed based on the average number of blocks walked each week. Researchers then gave them MRI scans two or three years later, another high resolution MRI after nine years, and cognitive assessments at nine and 13 years after baseline.
During this time, 116 of the volunteers experienced mild cognitive impairment or dementia.
Study results found that the baseline weekly walking predicted gray matter volume at the nine year follow up – those with the most physical exercise had significantly higher gray matter volume than those who exercised less frequently.
In this study, walking six to nine miles a week was associated with the greatest gray matter volumes – associated with reduced risk of cognitive impairment or dementia. Walking more than that did not make a further difference.
Another study by the same group of researchers and published this year in February found even beginning a moderate exercise program late in life led to increased brain volumes and improved memory function.
A different group of researchers from Washington University examined the relationship between exercise and four known Alzheimer’s biomarkers in 69 normal adults aged 55 to 88.
Researchers analyzed exercise levels in volunteers over the last 10 years and found that those with the lowest amount of physical exercise had elevations in one biomarker associated with increased risk of Alzheimer’s disease (Pittsburgh Compound B binding). Those who exercised more frequently experienced lower levels of this as well as higher amyloid B42 (a protective biomarker).
All of these studies seem to associate physical exercise with brain health in older adulthood. More research is needed to better understand what it is about the exercise that provides the protective effect – some theories suggest aerobic exercise sends oxygen-rich blood into the brain, which is the organ that needs the most blood. This kind of exercise is also known to increase levels of a chemical called brain derived neurotrophic factor, which promotes growth of new brain cells and protect them from age-related damage.
Regardless, this information gives just a few more reasons why it is important to keep getting the recommended amount of exercise (30 minutes a day at least five days a week) to maintain optimal health throughout life.