A fair number of new research results have appeared in the past few weeks relating to ways to modestly reduce the pace of cognitive aging. As we age the mind declines due to a range of failures in the physical structure of the brain that arise from the SENS catalog of low-level cellular and molecular damage of aging. One of the more important ways in which the physical structure of the brain is impacted is via failing cardiovascular health, meaning both a degeneration of the overall process of effectively driving blood through the brain and also a progressive failure of blood vessels, involving loss of tissue elasticity and structural integrity. You might read up on vascular dementia to see how the late stages of this process go, but it is worth remembering that significant damage and failing function exists in the brain's network of blood vessels long before it rises to the level of diagnosis as a named disease or catastrophic structural failure such as a stroke.
Aging is a progressive, accelerating decline that starts with small consequences and minor losses of function, easily ignored. But these small degenerations will also be repaired in a future of rejuvenation therapies: no-one will wait for decades before undergoing periodic treatments to repair the harms that accumulate in our biochemistry. The next big goal for medical science, something to work towards over the next half century, is an assurance of perfect health for everyone, continuing for as long as desired.
We are still a way away from that point, however, and so the researchers of today continue to point out that exercise remains one of the most effective means available to slow the onset of degenerative aging. That we live in an age of biotechnology and progress and that exercise is still head and shoulders above most medical technologies should really be taken as a challenge. We can do better, and we should do better, and we must do better if we want to live longer in good health.
For the study, sedentary adults ages 57-75 were randomized into a physical training or a wait-list control group. The physical training group participated in supervised aerobic exercise on a stationary bike or treadmill for one hour, three times a week for 12 weeks. Participants' cognition, resting cerebral blood flow, and cardiovascular fitness were assessed at three time points: before beginning the physical exercise regimen, mid-way through at 6 weeks, and post-training at 12 weeks.
Exercisers who improved their memory performance also showed greater increase in brain blood flow to the hippocampus. Using noninvasive brain imaging techniques, brain changes were identified earlier than memory improvements, implicating brain blood flow as a promising and sensitive metric of brain health gains across treatment regimens.
"Physical exercise may be one of the most beneficial and cost-effective therapies widely available to everyone to elevate memory performance. These findings should motivate adults of all ages to start exercising aerobically. In another recent study, we have shown that complex mental training increases whole brain blood flow as well as regional brain blood flow across key brain networks. The combination of physical and mental exercise may be the best health measures to improve overall cognitive brain health. We have just begun to test the upper boundaries of how we can enhance our brain's performance into late life."
Physical exercise, particularly aerobic exercise, is documented as providing a low cost regimen to counter well-documented cognitive declines including memory, executive function, visuospatial skills, and processing speed in normally aging adults. Prior aging studies focused largely on the effects of medium to long term (more than 6 months) exercise training; however, the shorter term effects have not been studied. In the present study, we examined changes in brain blood flow, cognition, and fitness in 37 cognitively healthy sedentary adults (57-75 years of age) who were randomized into physical training or a wait-list control group.
The physical training group received supervised aerobic exercise for 3 sessions per week 1 h each for 12 weeks. Participants' cognitive, cardiovascular fitness and resting cerebral blood flow (CBF) were assessed at baseline (T1), mid (T2), and post-training (T3). We found higher resting CBF in the anterior cingulate region in the physical training group as compared to the control group from T1 to T3. Cognitive gains were manifested in the exercise group's improved immediate and delayed memory performance from T1 to T3 which also showed a significant positive association with increases in both left and right hippocampal CBF identified earlier in the time course at T2.
These data suggest that even shorter term aerobic exercise can facilitate neuroplasticity to reduce both the biological and cognitive consequences of aging to benefit brain health in sedentary adults.