Physical and Mental Exercise and Their Effects on Dementia

As those of you know who read my blog, I have been a strong advocate for regular exercise because it is very helpful for physical and mental health at any age, particularly for the aging. (As an aging person, myself, I’ve had a bit of an axe to grind!)   I have also created  a questionnaire for people who have trouble motivating themselves to exercise to find out why they don’t (Exercise Questionnaire.)  I reasoned that learning why they don’t exercise at all or do it very infrequently might help them overcome their resistances and begin to do it.

A recent article by Kirsten Weir, in the American Psychological Association Monitor for July/August 2017 entitled Keeping Dementia at Bay (pp. 46-52).  is filled with some good information about to keep oneself mentally and physically sharp at an advanced age. 

First some statistics:  5 million people in the US are estimated to be living with dementia.  Alzheimers disease is the most common cause of dementia, accounting for 60 to 80 percent of those with the diagnosis.  Another fact is that the brain changes causing dementia are very slow, gradually accumulating for a decade or more before symptoms appear.

Since this is such a common disease, it is naturally being studied very carefully by many researchers.  Prevention is still he most important strategy; recent drug trials for medications to treat dementia failed to show any improvement at all.  But since brain changes are now visible before symptoms develop, there may be some hope in developing drugs in the future that may forestall or prevent dementia from occurring.

Dietary Factors and Dementia

Regularly drinking artificially sweetened soda increased the risk of stroke and dementia.   But researchers haven’t found any dietary regimens that specifically prevent dementia.   Midlife controls for diabetes, blood pressure, and cholesterol are important for maintaining physical health and, perhaps, slow the progress of dementia.

Exercise and Dementia

Many studies have shown that regular physical activity in midlife reduces the risk of dementia in later life.  And those people who showed signs of dementia or mild cognitive impairment who were enlisted in exercise regimens for 6-12 months had better cognitive scores than those who were sedentary.  There is also actual evidence now that exercise physically changes the brain.  For example, in one study it was found that older adults who engaged in a year of moderate aerobic exercise 3 days a week had an increase in the volume of the hippocampus.   This is important because the hippocampus is involved in transforming short term memory into long term memory.  The brain size difference was  also linked to better memory in the exercise group.   

Physical exercise also helps vascular health and vascular disease is a risk factor for dementia.

Exercising the Brain

The adage “use it or lose it” is particularly relevant in keeping the brain healthy.   There is evidence that those who have changes in the brain can still function normally.  One third of people upon whom autopsies after death were performed showed signs of Alzheimers disease in the brain, yet they displayed no memory impairment before death.  One factor that may be involved is that they exercised their brains as well as their bodies.    Mentally stimulating activities such as taking classes in college,  continuing intellectuallly challenging careers,  having plenty of leisure and social activities, appear to slow cognitive decline.


The most difficult issue is getting people to do the things they may already know they need to do to  keep their brains and the rest of their bodies healthy:  diet, exercise, cognitive training and vascular risk monitoring.   My experience is that it’s important to develop these habits earlier in life so that they become a routine part of one’s life.  But if one hasn’t done that, it is still possible to develop the habits later in life.  I will discuss various ways that can be accomplished in later postings.