23 November 2009
Strenuous Exercise linked to memory Loss
This study was presented at the Alzheimer’s Association 2009 International Conference on Alzheimer’s disease. Long-term strenuous physical activity has been shown to decrease lifetime exposure to ovarian hormones in women and has been found to play a protective role against breast cancer. However a decrease in ovarian hormone exposure has been associated with increased risk of cognitive impairment. Also, long-term physical activity is associated with improved cognition but the intensity required to preserve cognition is not known. Mary C. Tierney, PhD, and professor at the University of Toronto wanted to examine the relations between both long-term strenuous and moderate activity and cognition in recently postmenopausal women. The study had 90 women aged 50-63 years old who gave details on the amount of their strenuous and moderate physical activities from high school to menopause. Eight memory and brain function tests were administered to all participants. The researchers found that long-term strenuous activity was always associated with poorer performance on all eight of the tests. Moderate physical activity was always associated with better performance on all eight of the tests. The results suggest that long-term strenuous activity may increase the risk of cognitive impairment in recently postmenopausal women, but moderate long-term physical activity may improve later life cognition. Dr. Tierney says that further study is needed.
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Heres a link to the article from webMD for further information:
ReplyDeletehttp://www.webmd.com/fitness-exercise/news/20090715/strenuous-exercise-linked-to_memory-loss
Who would have known that exercising would later on result in memory loss. I wonder if there is anything similar for the male population between exercise and memory loss.
ReplyDeleteThis study seems very interesting, but there are so many other variables involved to believe that strenuous activity could really be one of the risk factors that leads to cognitive impairment. They should study extreme athletes (ironman athletes) that have gone through menopause and determine if there cognitive function has declined. I'm definitely not giving my strenuous exercise over this study. Thanks for the post!
ReplyDeleteSounds like an interesting study, but what were the qualifiers for long-term and strenuous? Without this sort of information and a self-report over so many years (high school through menopause), this study's claim seems rather weak taken at face value since it could be very subjective, especially given the high levels of error in self-reports of exercise and diet.
ReplyDeleteIt is true that this retrospective, self-report study can only give a very limited amount of information. However the background theory and rationale is quite consistant with what I have been seeing in studies elsewhere, making it worth further research.
ReplyDelete- Numerous studies have found an association between increased estrogen and imrpoved cognitive function. Hormone replacement therapy in women, for example, has been found to improve cognition.
- Physical activity is generally associated with improved cognitive function. This is repeatedly found in acute experimental studies of exercise, as well as longer-term observational studies. This could be mediated by factors such as Brain-Derived Neurotrophic Factor (BDNF), known to support neural health, which increases after exercise.
- The question of what intensity is useful for cognitive improvement is a very valid one. High intensity exercise increases cortisol levels, which are known to affect memory and cognitive function more generally, though often in a reversible manner.
Interestingly, inflammation may have a role to play. Alzheimer's disease, vascular dementia and mild-cognitive impairment are all associated with chronic low-grade inflammation. A very interesting study by Yaffe et al (2004), found that people with the metabolic syndrome were more likely to have cognitive impairment, but that those with the metabolic syndrome and low inflammation did not exhibit increased likelihood of impairment. Instead, participants with the metabolic syndrome and high inflammation were more likely to show cognitive decline over the 4 year study period. This is just one of a range of studies now suggesting a link between cognitive function and inflammation, however the mechanisms are still unclear.
- Of course, regular, moderate physical activity can reduce inflammation...
Yaffe, K. et al (2004). The Metabolic Syndrome, Inflammation, and Risk of Cognitive Decline. Journal of the American Medical Association. 292(18). 2237.