Aging leads to functional changes in the hippocampus, a brain structure that is critical to learning, causing the ability to learn new tasks to decline with age. At the cellular level, synaptic contacts, synaptic strength and plasticity are reduced, neurogenesis of the hippocampus decreases with aging, and imaging studies have shown atrophy of the hippocampus in older people.
These harmful consequences of aging can be prevented or reversed through exercise. In fact, older adults who exercise throughout their lives have less loss of brain tissue than sedentary individuals.
Lack of physical activity at any age is a major cause of obesity. Not only does exercise help improve physical health, but also academic performance, as the positive effects of physical activity on cognition and brain functions at the molecular, cellular, systems and behavioural levels are evident. A growing number of studies support the idea that physical exercise is a lifestyle factor that could lead to a more effective immune system.
The decline in neurogenesis in older mice was reversed by 50% with constant exercise. In addition, the good morphology of the new neurons did not differ between young and older runners, indicating that the initial maturation of newborn neurons was not affected by aging in those that are physically active.
Neuroinflammation and aging go hand in hand and exercise has powerful anti-inflammatory effects
Exercise, among other structures, affects the hippocampus which plays a fundamental role in learning and in the formation and consolidation of memory, participating critically in the regulation of emotions, fear, anxiety and stress. It regulates, balances all of this through hormonal and neurotrophic factors.
Exercise enhances and maintains synaptic plasticity, as well as long-term empowerment and depression (short and long-term memory).
Neuroplasticity is the ability to adapt and reorganize to internal or external stimuli and occurs at the cellular, network and behavioral levels, which is reflected in the architecture of the intrinsic properties of the neurons and circuits of the hippocampus.
Exercise increases the formation of new neurons in the hippocampus, which are necessary for new memory storage, as well as concentrations of neurotrophic factors and improved cognition. Possible circulating factors in the blood responsible for this effect were identified by plasma proteomics.
After exercise, in addition, we have circulating anti-inflammatory myocines of the skeletal muscle, and the liver and hepatic hepatocines are improved. The liver is an endocrine organ that emits its own factors, called hepatocins, as metabolic and immune system regulators and as I indicate, activated by exercise.
Likewise, we also lose fat because fat-derived adipocines are also activated. In recent years it has been recognized that adipose tissue secretes several bioactive molecules called adipocins or «adipocytokines», which come mainly from white adipose tissue (TAB) and play a major role in the homeostasis of several physiological processes, including food intake, regulation of energy balance, insulin action and glucose metabolism.
By exercising we activate resistance, leptin and adiponectin, described by their function in my book on Mediterranean Diet and Physical Exercise. It also participates in the general remodeling of vascularization, blood pressure regulation and coagulation. For example, sedentariness can lead to thrombosis and hypertension.
These factors can function not only directly in the brain but also, as exemplified in the work of Horowitz et al. through extensive cross-tissue conversation («Blood factors transfer beneficial effects of exercise on neurogenesis and cognition to the aged brain» Alana M. Horowitz, Science, 10 Jul 2020).
In conclusion: exercise directly affects the brain and involves a large amount of tissue. It is the only proven anti-aging medication. Continued stress over time is a critical factor in accelerating aging. And we are in a situation of collective stress because of the pandemic and because of the disruptive messages of the national institutional stability that are being taken care of by a couple of political groups, which believe that with this we win elections. This indicates that our welfare is not in their interest.
This text may be reproduced provided that PROA is mentioned as the original source
José Antonio Rodríguez Piedrabuena
Specialist in Psychiatry, and in management training, group and couples therapy