MedicalResearch.com Interview with:
Professor Emrah Düzel
Director, Institute of Cognitive Neurology and Dementia Research, OvG Univ. Magdeburg, Germany
Institute of Cognitive Neuroscience
University College London
Medical Research: What are the main findings of the study?
Professor Düzel: We found that even in old age, intensive and long-term (3 months) aerobic exercise can improve blood flow in the hippocampus, a brain structure that is of critical importance for memory. The increase in blood flow is evident during a resting state and this means that the exercise improves the overall perfusion of the hippocampus. Such effects had previously only been reported in young adults. As previously observed in young adults, the change in blood flow after exercise is related to the improvement of specific memory skills. We found the closest relationship between improved blood flow and recognition memory for complex objects. This is interesting because this type of memory is likely to benefit from “pattern separation”, a process that in animal studies of exercise is tightly associated with hippocampal neurogenesis.
However, we also found that the exercise-related improvement in hippocampal blood flow and in recognition memory was absent in the older seniors of our study cohort. Those who were beyond 70 did not show any improvement. We reasoned that this may have been due to higher levels of stress in the older seniors. Therefore, we investigated whether elevated serum cortisol levels dampened the benefits of exercise in the older seniors. But this was not the case making it unlikely that stress levels can account for these findings.
Medical Research: What was most surprising about the results?
Professor Düzel: The absence of a benefit of exercise on hippocampal blood flow and recognition memory beyond the age of 70 was surprising. This is certainly something we need to replicate and investigate further in the future.
Medical Research: What should clinicians and patients take away from your report?
Professor Düzel: This was a proof-of-concept study looking at the effects of long-lasting exercise on resting blood flow in brain structures that are important for memory faculties that decline in Alzheimer’s Disease. Our study indicates that the positive benefits of exercise on blood flow and recognition memory are preserved in old age but starting exercising before the age of 70 may be more effective. It is well possible, however, that even starting regular exercise beyond the age of 70 may be beneficial. That benefit may not be an enhancement of brain function but rather a preservation of it. However, it is too early to make conclusive recommendations along these lines.
Medical Research: What recommendations do you have for future research as a result of this study?
Professor Düzel: Future research should have a stronger focus on the effects of advancing age on brain plasticity. We need to understand the physiological and molecular brakes on vascular plasticity in the hippocampus that emerge with advancing age. There may be potential for pharmacologically enhancing plasticity in response to exercise.
A Maass, S Düzel, M Goerke, A Becke, U Sobieray, K Neumann, M Lövden, U Lindenberger, L Bäckman, R Braun-Dullaeus, D Ahrens, H-J Heinze, N G Müller and E Düzel
Molecular Psychiatry , (14 October 2014) | doi:10.1038/mp.2014.114