Recent Evidence for Exercise to Improve Cognitive Function via Increased BDNF
There is a fair amount of evidence from the past decade to show that exercise improves cognitive function in both young and old individuals. A subset of that data points towards increased levels of BDNF as one of the mediating mechanisms. A great deal more work is needed to flesh out the current understanding of the enormously complex biochemistry involved in the effects of exercise on the brain, of course, but that doesn't stop some researchers from optimistically considering pharmaceutical approaches to mimic some of the beneficial effects of exercise.
The health advantages of high-intensity exercise are widely known but new research points to another major benefit: better memory. The findings could have implications for an aging population which is grappling with the growing problem of catastrophic diseases such as dementia and Alzheimer's. Scientists have found that six weeks of intense exercise - short bouts of interval training over the course of 20 minutes - showed significant improvements in what is known as high-interference memory, which, for example, allows us to distinguish our car from another of the same make and model.
The findings are important because memory performance of the study participants, who were all healthy young adults, increased over a relatively short period of time. The researchers also found that participants who experienced greater fitness gains also experienced greater increases in brain-derived neurotrophic factor (BDNF), a protein that supports the growth, function and survival of brain cells. "Improvements in this type of memory from exercise might help to explain the previously established link between aerobic exercise and better academic performance. At the other end of our lifespan, as we reach our senior years, we might expect to see even greater benefits in individuals with memory impairment brought on by conditions such as dementia."
For the study, 95 participants completed six weeks of exercise training, combined exercise and cognitive training or no training (the control group which did neither and remained sedentary). Both the exercise and combined training groups improved performance on a high-interference memory task, while the control group did not. Researchers measured changes in aerobic fitness, memory, and neurotrophic factor, before and after the study protocol. Now, researchers have begun to examine older adults to determine if they will experience the same positive results with the combination of exercise and cognitive training. "One hypothesis is that we will see greater benefits for older adults given that this type of memory declines with age. However, the availability of neurotrophic factors also declines with age and this may mean that we do not get the synergistic effects."
This sounds like an interesting line of research employing an exercise and cognitive training to determine memory decline rate in aging adults and if and to what degree it is slowed. One other thing that should be followed is the geneotype of the BDNF each individual has. The BDNF SNP rs6265 AA allele is susceptible to quicker decline with Alzheimer's, while the GG allele is the normal allele and will have slower cognitive decline with aging. About 40% of Caucasians have the good BDNF allele.
The last sentence of my above comment should be about 60% of Caucasians have the good BDNF allele. I was looking at the wrong end of the scale.