December 15, 2019 4: 00 am
Train and be active and may help with memory and ward off dementia
Jennifer J. Heisz
Associate professor of kinesiology, McMaster University
For the first time in the history of mankind, the elderly are more numerous than the young. This presents a challenge for the field of health.
Dementia is without doubt what is most frightening – a debilitating condition that erases the memory ; a disease with no possible cure, at least for the moment.
But we are not necessarily doomed. Because physical activity protects us against the loss of our memories, and according to our most recent studies, it is never too late to start.
As associate professor in the department of kinesiology at the University of MacMaster, I lead a team of researchers from the NeuroFit lab where we have shown that physical inactivity contributes just as much as the genetics in the risk of dementia.
Our research suggests that the intensity of the exercises is a significant element. We recruited sedentary elderly in a new physical activity program, and in just twelve weeks, their memory improved. But this occurred only among those who market with a stronger intensity, and their revival of memory was directly related to the improvement of their physical condition.
The next step will allow us to understand how physical activity alters brain activity – so that we can establish routines tailored to counteract the effects of aging on brain health.
Train for a healthy brain
As the population ages, we all run the risk of suffering from dementia. As a part of our destiny is predetermined by biological factors. Aging is a major risk factor for dementia, and certain genes also increase the probability.
But recently we have begun to recognize the role played by our hygiene of life. New evidence pointing towards a decrease in cases of neurodegenerative diseases and this, despite the aging of the population. And the reason is to be found in the improvement of our living conditions, education, and health care.
One of the biggest risks that is changing the landscape, it is physical inactivity. And it is this observation that provides us with the ability to train the brain in better health.
Physical activity lowers the risk
A study conducted by my laboratory has analyzed the interaction between genetics and physical activity on a group of more than 1600 seniors who took part in the Canadian Study of Health and Aging.
Approximately 25 percent of our sample reported risk of dementia genetic, but this was not the case for the majority (about 75 percent). This sample is representative of the population as a whole. None of the participants had symptoms of dementia at the beginning of the study, and we performed the follow-up five years later.
Here is what we found : 21 percent of people at risk because of their genetic background developed symptoms of dementia, and the physical activity had no effect on them. By contrast, in subjects without genetic risk, those who were physically active had a risk lower dementia than those who were inactive.
Critically, the inactive have presented a level of risk equivalent to those who were genetically predisposed to dementia. In other words, the physical inactivity may lead to dementia, even if the genes do not predispose not. You can not change his genes, but we can change the way of life !
The exercise is like fertilizer
It turns out that physical activity helps in the regeneration of the brain : it actually grow new neurons at the level of the hippocampus, which improves memory.
Although we do not understand perfectly how this works, we know that exercise increases the brain-derived neurotrophic factor (BDNF), which acts as a fertilizer promoting the growth, functioning, and survival of new cells.
These new neurons fit together like pieces of a puzzle, each element of which represents a different aspect of the memory. When we have more new neurons, we are able to create memories to be more detailed and less likely to be erroneous. For example, it will be remembered, if he has taken his medication yesterday or today, or even where we parked his car in a parking lot crowded.
We have demonstrated that physical activity improves neurogenesis in memory, either in young adults as in older.
The sweating, it counts !
The seniors took part in three weekly sessions. Some have practiced interval training of high intensity, other training, continuous moderate-intensity, while a control group practiced as stretching.
The protocol of interval workout high intensity training consisted of four sets of four minutes of exercise on treadmill, followed by a recovery period. The continuous training of moderate intensity consisted of a period of aerobic exercises of moderate intensity over a period of 50 minutes. Each fiscal year was adjusted to take account of the physical shape of the participants.
Only the seniors that are part of the group of interval workout with high intensity showed symptoms of improvement in the memory neurogenetics. No improvement was seen in people who followed a program of continuous training of moderate intensity, no more than in the control group.
These results are promising, because they suggest that it is never too late to benefit from a brain health improved by being active. But if you start late and want fast results, you will need to increase the intensity of your exercises.
You can achieve this by incorporating hills into your routine, walking daily, and speeding up the rhythm between two poles. This will allow you to keep dementia at a distance and to contribute to an old age in good health for a population growing more and more.