The Role of Physical Activity in Brain Health

By Ms Shashi Soni, Teaching Associate, Amity Institute of Dietetics and Applied Nutrition, Amity University Gurugram

Introduction: Physical activity has been known for a long time to improve cardiovascular, metabolic, and musculoskeletal health. Now, substantial and fast-growing research has come forward to show that physical activity is crucial for brain health as well, basically throughout life and beyond. This review examines the major brain changes resulting from exercise, the scientific evidence from clinical and observational studies, and the preventive implications for neurodegenerative disorders. Physical activity changes the brain through a set of changes at both biological and physiological levels that encourage neuronal survival, growth, and function. In recent times, several landmark syntheses have reviewed and summarized the scientific evidence of one main outcome: exercise leads to a chain of neurobiological effects: Neurotrophins and Growth Factors: Among the different processes triggered by exercise is the one that calls for the release of brain, derived neurotrophic factor (BDNF), nerve growth factor (NGF), insulin, like growth factor, 1 (IGF, 1), and other neurotrophins that facilitate neurogenesis, synaptic plasticity, and neuronal survival. Especially, BDNF is the molecule responsible for long-term potentiation, which is the cellular basis of learning and memory. Neurovascular Adaptations: Physical exercise keeps the brain's blood flow at an optimal level by removing wastes and by distributing oxygen and nutrients more efficiently to brain tissues. Besides that, it activates angiogenesis (the creation of new blood vessels) in the like the hippocampus, which is necessary for memory storage.

Anti-Inflammatory Effects: Regular physical activity lowers systemic and central inflammation through the upregulation of anti, anti-inflammatory cytokines and downregulation of pro, pro-inflammatory molecules. Since chronic inflammation is a major cause of cognitive decline and neurodegeneration, this is very important. Mitochondrial and Antioxidant Function: Exercise increases mitochondrial biogenesis and antioxidant defenses in the brain, thus lessening oxidative stress that leads to neuronal damage. Neurotransmitter Regulation: Exercise promotes the release of neurotransmitters such as dopamine and serotonin that regulate mood, cognition, and executive functioning.

Physical activity influences the brain progressively, as it is the main source of the growth of new nerve cells and the cognitive abilities in children and adolescents. According to a narrative review of the literature, children who are physically active have better inhibitory control, working memory, and cognitive flexibility, which is probably due to enhanced neurotransmission and oxygen supply, as well as to long-term structural changes in the brain. These findings have significant implications for the learning environment, where the inclusion of physical activity can enhance cognitive skills and academic achievements. Chronic interventions have been linked to white matter integrity and network efficiency enhancement; thus, continued activities lead to brain changes that are lasting.

In the case of adults, the practice of physical activity on a repetitive basis is highly correlated with the preservation of cognitive performance with old age. The results of longitudinal and cross-sectional studies demonstrate that regular exercise is associated with better general cognition, memory, and executive function, even after taking into account factors such as cardiovascular and metabolic health.

Consequently, the alleviation of depressive symptoms is one of the factors that partially explain the associations between physical activity and cognitive function; in that, depressive symptoms are responsible for some of the cognitive benefits in physically active individuals. This implies that exercise is a means of emotional health, which, in turn, enhances cognitive resilience.

Neurodegenerative diseases such as Alzheimer's disease (AD) are characterised by cognitive decline, loss of synapses, and the deposition of pathological proteins. In support of this, evidence from randomised controlled trials and meta-analyses shows that frequent physical activity can either improve or slow down the process of cognitive decline in individuals with mild AD. In fact, exercise also affects molecular pathways involved in neurodegeneration. As an illustration, the physical activity-related transcriptional patterns show an inverse correlation with those in AD, Parkinson's disease, and Huntington's disease, therefore, implying that exercise may have neuroprotective effects in different pathological states. Besides, physical activity has been found to have an effect on such neurodegeneration, related processes as amyloid, beta aggregation, tau pathology, and microglial activation, thus providing a mechanistic rationale for population studies. In essence, physical activity serves as a non-pharmacological intervention that supports cognitive reserve and slows down neurodegenerative progression, although the exact dose and response relationships are still unclear and need more investigation. In addition, any physical activity, even non-exercise activities, can still be beneficial for the brain. For example, research shows that household physical activities, such as regular chores, are positively related to grey matter volume as well as the volume of the hippocampus in the elderly.

These results highlight that total movement throughout the day, without regard to the type of movement, is related to brain structure and could potentially offset brain atrophy associated with aging. While the most effective exercise prescriptions (frequency, intensity, duration, and type) are still being determined, short bouts of exercise have been shown to be beneficial to cognition. Consistency seems to be more important than intensity alone, thus making physical activity accessible and achievable for the majority of people. Physical activity is a significant and scientifically proven factor that influences brain health in various ways and through different neurobiological mechanisms. It affects cognitive function, the structural integrity of the brain, and the risk of neurodegenerative diseases. Regular movement throughout childhood development and even old age supports neural growth, synaptic plasticity, and cognitive resilience. As sedentary lifestyles are increasingly becoming the norm globally, the promotion of physical activity should be seen as a necessity not only for physical well-being but also as the basis of brain health at all stages of life.

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Skills Required to be a good Dietitian & Nutritionist:

·        Strong knowledge of nutrition and dietetics

·        Good communication skills to explain diet plans clearly

·        Empathy and compassion for understanding clients’ needs

·        Analytical skills to assess health data and dietary habits

·        Problem-solving ability to create effective meal plans

Career opportunities for a Dietitian & Nutrition:

·        A Clinical Dietitian

·        Community Dietitian

·        Sports Nutritionist

·        Corporate Wellness Consultant

·        Food Industry / Product Development

Relevant Courses in B.sc Dietetics & Applied Nutrition:

·        B.Sc. Dietetics & Applied Nutrition (Hons/ Hons with Research)

·        Bachelor in Nutrition and Dietetics (Honours)

·        M.Sc. Dietetics & Applied Nutrition

·        Doctor of Philosophy (Dietetics & Applied Nutrition)

·        Doctor of Philosophy (Dietetics & Applied Nutrition) - Part Time

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References

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