Studies show that regular physical activity can actually produce changes in the brain that protect memory and thinking skills. Recent research from the University of British Columbia found that regular aerobic activity actually increased the size of the hippocampus – the area of the brain involved with verbal memory and learning. Aerobic exercises are the kind that really get your heart pumping, often referred to as "cardio." The study found that resistance training, balance and muscle-toning exercises did not promote the same results.
This new finding comes at a critical point in time, as dementia seems to be expanding at an alarming rate. Researchers estimate that one new case of dementia is diagnosed every four seconds worldwide. They posit that more than 115 million people will have dementia across the globe by the year 2050. It's not exactly a bright forecast for the world's future, but this new finding may provide a key to prevention.
Exercise can provide benefits to cognitive health both directly and indirectly. Benefits come directly through its ability to help reduce insulin resistance, decrease inflammation and promote the release of growth factors, which are chemicals in the brain that affect brain cell health, the development of new blood vessels within the brain, and the profusion and endurance of new brain cells.
Dr. Scott McGinnis, a neurologist at Brigham and Women’s Hospital and an instructor in neurology at Harvard Medical School commented, "Even more exciting is the finding that engaging in a program of regular exercise of moderate intensity over six months or a year is associated with an increase in the volume of selected brain regions."
A number of studies have suggested that the parts of the brain that control thinking and memory – the prefrontal cortex and the medial temporal cortex – seem to be more voluminous in people who exercise compared to those who do not do so.
For example, a study from the University of California, Los Angeles (UCLA), was published in the Journals of Gerontology Series A: Biological Sciences and Medical Sciences in the summer of 2016. Those researchers also found that engaging in regular physical activity impacted the size of the hippocampus. They determined that the protective effect of exercise was most pronounced in people who were 75 years of age or older.
In the UCLA study, researchers analyzed the physical activity indices for 3,700 people, divided into two cohorts. The first group had initially participated in the 1948 Framingham study, which sought to trace factors and characteristics that led to cardiovascular disease, but also dementia and other physiological conditions. The second group of people consisted of the original study participants' offspring, all of whom were 60 years of age or older. The scientists then looked for associations between physical activity and risk of any form of dementia and Alzheimer's disease. About 2,000 subjects from the offspring cohort also had MRI scans of their brains examined for possible associations with physical activity.
Their findings suggest that it really is never too late to start exercising for brain health, and to help reduce the risk of dementia.
So what should you do? Start moving! In the study from the University of British Columbia, participants engaged in brisk walking twice weekly for a one-hour period. That equates to 120 minutes of moderate-intensity activity. Most research has looked at walking as a physical activity, but it is likely that other forms of aerobic activity would provide similar benefits. While the standard recommendation is at least 150 minutes of activity per week, we all have to start somewhere! Even if you have to start small, it's better than nothing.