There are many benefits of doing regular exercise such as maintaining a healthy weight and keeping many health conditions at bay. A team of experts has found that regular physical activity also guards the structure and function of the brain, as people grow old. Experts have said that regular exercise can reduce the risk of being diagnosed with some neurodegenerative issues such as dementia and Alzheimer’s disease. Though scientists have been advocating about the protective effects of regular exercise, why exercise has a positive effect on the brain has been unknown. However, the new study has shed some light on this mystery. The findings of the new study have shown that regular exercise changes the activity of immune cells of the brain. It cuts down the level of inflammation in the brain. Experts have said that the brain carries a specific set of immune cells that are known as microglia.
These immune cells constantly review the brain tissue for any damage or infection and they clean debris or other toxic accumulations from the brain. These immune cells trigger the production of new neurons via a mechanism known as neurogenesis. Neurons are nerve cells in the brain that correspond and transmit messages to other cells. Neurogenesis is associated with learning and memory tasks. Microglia need to change their dormant state to an activated state in order to be able to step up and do their task. Experts have informed that signals coming from foreign invaders like viruses or infected cells stimulate microglia. This process alters their shape and leads them to generate pro-inflammatory molecules. It helps microglia to repair damaged cells or prevent further infection, said the experts. The findings of the new study have been presented in the Journal of Neuroscience.
The authors of the study have said that on the other hand, microglia can be improperly stimulated as people start aging, which leads to severe inflammation in the brain and destruction of neurogenesis. Scientists have claimed that this type of inflammation might be responsible for the decline in the functionality of the brain as people age. These alterations can be even more toxic in the case of neurodegenerative issues such as Alzheimer’s disease. Many studies on mice and rats models in the labs have shown that regular physical activity can offset some of the harmful effects of improper activation of microglia. However, for the first time, the new study has found a link between exercise, low microglia activation, and improved cognitive function in the human brain. The authors of the study have observed 167 men and women who have been part of the Rush Memory and Aging Project. It is a long-term program that has been carried out by experts from Rush University in Chicago.
The project aims to find out the factors that are responsible for brain health among elderly people. All participants have finished yearly assessments of their physical activity that has been tracked by wearable activity trackers. They have finished assessments of their cognitive ability and motor function as well. Motor performance is referred to walking speed and muscle strength said the experts. Some volunteers have also donated their brains for post-mortem study that has been a part of the long-term study. This has helped scientists to examine the brain tissue for signs of stimulated microglia and other infections in the brain such as damaged blood vessels and the prevalence of plaques of the protein beta-amyloid beta that is a sign of Alzheimer’s disease. Scientists as well have analyzed the levels of synaptic proteins in the brains of the participants. Synapses are considered small links between nerve cells where information is broadcasted; therefore, the levels of synaptic proteins are major signs of the healthy functioning of the brain.
Participants have been around 80 years old when experts have started tracking the levels of their physical activity and at the age of 90 years, they have died. As per the findings of the study, nearly a third of them have not been found with any cognitive damage. While a third of them have been diagnosed with mild cognitive decline and a third of participants have been detected with dementia. However, a post-mortem study has shown that nearly 60 percent of the participants have been found with signs of Alzheimer’s disease in the brain that means they have been found with amyloid buildup in the brain. Health experts have claimed that the findings show that the existence of classic signs of Alzheimer’s disease does not essentially mean that a person will have major symptoms of the disease while they are alive. The findings of the study have found that younger participants who have been physically more active have shown better motor function. The authors of the study have claimed that overall being more active has been linked to lower activation of microglia in some areas of the brain such as the inferior temporal gyrus that plays a vital role in memory and recall function. This region of the brain is usually impacted in the early stage of Alzheimer’s disease. The study has noted that regular exercise can lessen the harmful effects of inflammation in the brain even when the disease starts growing.
The findings of the study have shown that more activation of microglia has been linked to higher cognitive damage and reduced levels of synaptic protein. The study has noted that inflammation in the brain can majorly impact cognitive ability and it can be a risk factor for Alzheimer’s disease as well. However, some experts have found some limitations to the new study. They have said that post-mortem study has shown only one single snapshot in time of the status of the brain; it means that it is hard to find out when the signs of Alzheimer’s have started developing in participants’ brains and at what point of time exercise has made a beneficial difference. The study has been an observational one that means that it has only looked at changes participants have experienced in their lifetime. The findings of the study have not been able to show the mechanism by which physical activity leads to a beneficial effect on the brain. Still, the findings of the study add to the growing body of data that regular exercise can improve brain health and cognitive function even in elderly people. Health experts have said that being physically active throughout life can prevent Alzheimer’s disease and other neurodegenerative issues from developing. It helps people live long, healthy, and independent lives as well.