Physical Exercise's Effect on Dementia

Dementia is a growing problem for our aging population.  The statistics are staggering, estimating that 10% of 65-year-olds, 25% of 75-year-olds, and 50% of 85-year-olds will develop dementia.  Alzheimer’s disease accounts for the largest fraction of dementia cases, with Lewey bodies, vascular disease, and other disorders contributing.  Less severe but not to be overlooked, mild cognitive impairment (MCI) is documented in more than 10% of people over 70 years old and 20% over 80.  MCI is often a precursor to dementia.

As the dementia problem continues to grow, solutions are sought after to counter the results.  However, these disorders are only minimally understood and often affect people on a very individualized basis, so treatment has proven difficult.  There are currently no medications that have been proven to reduce the risk of dementia or age-related cognitive impairment. 

Although modern medicine has found no solution, there is growing evidence that physical activity is beneficial in the risk and prevention of dementia.  The benefits are seen with long-term, regular exercise that is sufficient to raise the heart rate and increase the need for oxygen.  Exact parameters on the quality and quantity are difficult to define in the literature, but frequency and duration are required across the board.  Multiple sessions per week of at least 20-30 minutes of activity seem to be accepted as sufficient.

So what is the connection between exercise and brain-aging?  There are several trains of thought on the positive effects.  The most accepted benefit is the influence of exercise on cerebrovascular disease; meaning exercise improves the health of blood vessels.  Healthy blood vessels contribute to proper oxygen and nutrient distribution in the brain tissue, allowing the brain to function at its best.  Functional MRI studies have also been done to show neuron connectivity improve with the introduction of exercise.  There have even been studies that show the volume of particular areas of the brain, specifically, the hippocampus, increase after significant amounts of exercise.  The hippocampus is associated with emotions and memory, particularly long-term memory. 

There is no questioning the worry dementia and brain-aging diseases have on our population. Besides depleting the life quality of the affected patients, dementia also becomes a burden to immediate family, both in caregiving and financial capacities.  With overwhelming evidence that physical activity can help this problem, I believe that every capable person should be exercising to some extent.  Of course, there is a huge benefit to exercising regularly before the onset of brain-aging diseases, so get started today!

Yours in Health, Dr. Alex Ognibene