Exercise Benefits Individuals with Cognitive Impairments

Summary
There is limited research exploring the use of physical exercise for improving cognitive functions like thinking, learning and remembering. Earlier studies have demonstrated similar benefits in animals, but there is little research for humans. This study was undertaken to demonstrate if regular aerobic exercise for six months in older adults with mild cognitive impairment (MCI) could provide benefits to cognitive function and also to explore why this may work. Results showed that in women, regular aerobic exercise improved cognitive functions. In both men and women, aerobic exercise also improved certain parameters like levels of insulin and stress hormones like cortisol. Per the researchers this study proves that there are effective non-drug measures that can improve cognitive functions especially among elderly women who may be at risk.

Introduction
Earlier studies on animals have shown beneficial effects of exercise on memory and other cognitive functions. However, there have been no concrete studies to either quantify the benefits of exercise in elderly humans with cognitive impairment or to explore the mechanism behind such benefits. In an attempt to measure the exact benefit that such exercise can provide, this study explored levels of some biochemical markers in blood like insulin, stress hormones like cortisol, etc. These parameters can be distorted in patients who have cognitive difficulties like in Alzheimer’s disease. The study planned to assess the benefits, explore their mechanism and see if gender could be a factor in predicting benefits from aerobic exercise.

Methodology
* A total of 33 adults, including 17 women, with mild cognitive impairment or mild memory loss aged from 55 to 85 years were included.
* Participants were divided randomly to perform either supervised aerobic exercises or stretching exercises for up to one hour per day, four days a week, for six months.
* Blood levels of insulin, cortisol, etc. were measured before the intensive exercising sessions and after the sessions were completed. For analysis of cognitive functions, tests to evaluate memory, executive function, verbal fluency, etc. were performed using several standard test formats before and after the exercise regimen.

Results
* When patients underwent the six-month aerobic exercise training, they derived specific benefits in their memory and cognitive functions.  This was seen more among women. Women also benefited in terms of other metabolic factors determined by blood levels of insulin and other parameters.
* Both men and women gained heart and lunch fitness and saw a reduction in body fat.
* Women showed better performance in executive function tests that tested cognitive skills and recall, and also had lower blood levels of cortisol, insulin and other parameters like BDNF (brain-derived neurotropic factors).This meant that the glucose in their bodies was being used more efficiently than before.
* At the end of the session, men performed better only in one of the cognitive function tests

Shortcomings/Next steps
The researchers note that patient safety was the primary concern and the inability of many of the participants to perform intensive exercises excluded them from the study, leading to a smaller sample. They agree that the sample size was inadequate to make definite conclusions and larger studies are warranted to explain the cognitive benefits of aerobic exercise.

Conclusion
Aerobic exercise is an inexpensive practice that is linked with numerous physical benefits like strengthening of the heart, increase in stamina, etc. This study suggests that it also affords a cognitive benefit for some elderly patients with mild cognitive impairment, without the expense or side effects of drugs. More pronounced effects of this form of exercise are noted in women, along with other features of improvement in glucose metabolism. Although not significant in this study, regular exercise that raises the heart rate can provide cognitive benefits to both men and women suffering from age-related cognitive damage. These benefits are over and above the physical benefits of regular exercise.

For More Information:
Effects of Aerobic Exercise on Mild Cognitive Impairment
Publication Journal: Archives of Neurology, (Reprinted) Jan 2010
By Laura D. Baker, PhD; Laura L. Frank, PhD; University of Washington School of Medicine, Seattle

*FYI Living Lab Reports Are Summaries of the Original Research.