Of all the exercises, aerobic exercise is mostly recommended by health experts and for good reasons because a new study by Laura D Baker from the Wake School of Medicine (WFSM) proves that aerobic activity can decrease the risk of Alzheimer’s by boosting brain volume and improves memory, learning and concentration in old people with mild cognitive impairment (MCI).
People above the age of 60 with mild cognitive impairment are at increased risk of developing dementia, especially Alzheimer’s disease (AD), which is the most common form of dementia. Latest statistics from the Centers for Disease Control and Prevention (CDC) report that there are currently 16 million people in the United States living with cognitive impairment while there are 5.1 million people with Alzheimer’s disease.
The study enrolled 35 adults with MCI in a randomized, control trial involving exercise intervention. 16 adults with an average age of 63 years engaged in aerobic exercise on a treadmill, stationary bike or elliptical trainer four times per week for six months. Another group consisting of 19 adults with an average age of 67 years was placed in a control group and they engaged in stretching exercises in the same time span with the same frequency.
Aerobic exercise is the type of physical exercise that focuses on the abundant requirement of oxygen to activate the energy-generating process. This increases the heart beat rate as the lungs strive to provide proper levels of oxygen to the oxygen demanding parts of the body while also activating aerobic metabolism.
Aerobic exercises include running, swimming, cycling, walking and also dancing.
Using a new MRI method, high resolution brain images were acquired from all participants before and after the six-month period. The MRI results were compared using biomechanical and conventional methods to measure the anatomical changes in the volume and shape of the brain to obtain volumetric data and directional information.
The researchers found that adults with mild cognitive impairment experienced improvement in their brain functions in specific locations of their brain when they exercised four times per week over a six-month period. In contrast, those adults who took time for aerobic exercise experienced significant improvement in brain health.
The analysis revealed that both aerobic and stretching exercises increases brain volumes, especially in the gray matter regions, including the temporal lobe which is responsible for short-term memory.
But the scientist observed greater improvement in the adults who were involved in aerobic exercise as they observed increased volume of local gray matter and of directional stretch of brain tissue.
The scientists also noted that the results of the participants of the control group revealed atrophy of the white matter connecting fibers, atrophy being the gradual decline of tissue or cells due to underuse, and this type of shape change is related to volume loss.
MRI tests are important to measure the treatment of MCI and AD, which require careful tracking of the changes in brain matter and shape while patients are given medications. They are also recommended exercise and proper diet to slow the progression of the disease.
Jeongchul Kim, PhD, co-investigator on the study from WFSM, says, “Directional changes in the brain without local volume changes could be a novel biomarker for neurological disease. It may be a more sensitive marker for the tiny changes that occur in a specific brain region before volumetric changes are detectable on MRI.”
He adds, “Any type of exercise can be beneficial. If possible, aerobic activity may create potential benefits for higher cognitive functioning.”
These findings were revealed in the Radiological Society of North America (RSNA) 102nd Scientific Assembly and Annual Meeting in 2016.
National Institute for Health (NIH) recommends adults aged 65 years and above should be physically active and should do at least 150 minutes of exercise each week. And if they cannot be so active, they should gradually increase their activity levels while avoiding vigorous activity at first.
Another study reveals that in addition to improving physical health and building a stronger immune system as well as keeping diabetes, hyper stroke, heart diseases and cancers at bay, exercise can improve brain functions and leads to better cognition. The study indicates that running triggers the production of the protein cathepsin B (CTSB) which is released by skeletal muscle culture cells.
CTSB is an enzymatic protein encoded by the CTSB gene. Once produced, it is stored in the lysosomes in the cell membranes where it maintains the metabolism of the cells. It is also involved in other physiological processes such as the activation of hormones as well as in the prevention of diseases like tumor, inflammation, cancer and pancreatitis.
The scientists found that CTSB has an effect on the brain and affects short-term and long-term memory. When applied to the brain, it triggers neurogenesis which is the production of neurons.
The study also points that people who hold off aerobic exercise until later in life are still able to gain benefits from exercise in their later years.
Among the numerous benefits of exercise are improvement in social cognition, working memory and the attention span of people with schizophrenia.
Schizophrenia is a disorder which affects the way a person thinks, feels and acts. The person may have difficulty distinguishing between real and imaginary things or situations.
In schizophrenia, cognitive functions are also impaired. The person has lower processing skills, inferior decision making skills and a short attention span. Therefore, a person engaging in aerobic exercise can benefits greatly as exercise enhances brain health and mental performance.
Although a better and abundant supply of oxygen to the brain is one of the reasons for making new neural connections in the brain, there are growth factors in the brain which play an important role in the development of neural connections.
One of the effects exercise causes in the brain is the regeneration of axons in sensory neurons. Exercise has shown to induce brain-derived neurotrophic factor, neurotrophin 3, synapsin I, and GAP43 mRNA levels in the brain.