Building resilient brains: strategies for promoting brain health in older adults

By Neha MathurJun 21 2023Reviewed by Lily Ramsey, LLM

In a personal view published in The Lancet Healthy Longevity, researchers reviewed the overarching theme of brain health from the perspective of aging and preventive care. 

They searched PubMed for research papers published between Jan 1, 2002, and Jan 1, 2023. Based on this data, they discussed the mechanisms governing aging and brain aging, the interplay of forces that deviate a healthy brain toward disease condition to propose strategies that boost brain health.

Study: The role of population-level preventive care for brain health in ageing. Image Credit: SewCreamStudio/Shutterstock.com

Background

Mechanisms acting in other tissues cause brain aging, a complex biological phenomenon represented by an apparent decline in cognitive, social, and motor skills. Researchers have found and evaluated several markers for structural and radiographic brain changes, e.g., thinning of the brain cortex, global brain atrophy, and brain weight loss.

At a molecular level, telomeres have emerged as markers of aging, though their length does not always correlate with other brain aging markers, e.g., alterations in hippocampal volume.

Research has also implicated epigenetic modifications with chronological age and cognitive deficits, but more research is needed to establish a link between epigenetic changes and pathophysiology.

Trajectories of accelerated versus delayed brain aging

Researchers have uncovered that accumulating stress from multiple factors, including hypertension, smoking, sedentarism, and inadequate sleep, injure the brain over time. This stress builds up and overwhelms compensatory repair mechanisms, resulting in brain impairment beyond repair.

Likewise, early life exposure to metabolic and environmental stressors exhausts these systems, resulting in increased allostatic load, a concept introduced by McEwen and Stellar in the 1990s. Allostatic load occurs when stressors accumulate while repair mechanisms fail, which tips a system into dysregulation, implying irreversible brain damage.

Similarly, neuroinflammation is an important contributor to accelerated brain aging. Though high amounts of interleukin-6 have helped predict cognitive decline in longitudinal studies, there is a lack of appropriate radiographic or biological predictors of brain aging.

Another important theoretical brain aging concept is a cognitive reserve, also known as resilience, brain–age gap, and compensation. It describes differences in susceptibility to cognitive, functional, or clinical decline due to aging or brain disease.

It originated from the observation that the association between neuropathology and clinical cognitive function is variable.

Maintenance of brain health, i.e., age-appropriate brain function through all stages of life, is crucial to positively influence the well-being and quality of life of individuals and their families.

It is not just the absence of structural and molecular pathologies but the preservation of thought processing, executive planning, sensory and motor function, and memory and emotional connection.

Preventive approach for brain aging

Most brain diseases have long preclinical phases during which it is possible to manage aggressive risk factors among high-risk patients. By adopting a preventive focus on brain aging, a neurologist could change the intensity and frequency of exposure to such modifiable and transient risk factors. Examples include mild cognitive impairment, minor traumatic brain injuries, and ischaemic attacks.

Since disease-reversing therapies for most brain diseases are scarce, prevention appears to be the most effective intervention. However, this approach requires advancing partnerships and collaborations among all stakeholders, primary care physicians, neurologists, and preventive cardiologists.

Studies have recognized links between conventional midlife cardiovascular risk factors, cognitive decline, and aberrant brain structural changes in later life. Besides, the neuroscience community can serve other roles to improve brain health at the individual and population levels despite aging.

Advancements in treatment techniques for mild cognitive impairment and dementia emphasize the significance of high-risk approaches, e.g., lecanemab. Though the interventions in high-risk groups are effective, their effects could be small.

Thus, population-wide interventions are needed to change the duration of exposure to risk factors at the population level. Consequently, the combination of both approaches leads to increased benefits.

In the past century, cardiovascular diseases, cancer, and degenerative diseases have surpassed infectious diseases as leading causes of mortality globally, thus, considered an epidemiological transition.

Given the rapidly increasing number of elderly and the burden of neurological conditions globally, further collaborative efforts are urgently needed to promote brain health.

The American Heart Association (AMA) updated the concept of Life's Simple seven and added sleep as the eighth modifiable health behavior that, when optimal, lowered the risk of vascular, metabolic, and cognitive health decline. The other seven factors are a healthy diet, physical activity, abandoning smoking, maintaining a healthy weight, normal lipid concentrations, blood pressure, and normoglycaemia. 

Though Life's Essential eight brings additional improvements over Life's Simple seven, it recognizes that these factors are not easy to adopt, thus, need promotion through primary care interventions or health awareness campaigns.

Systemic changes to revised healthcare systems could ensure that the healthy choice can be easy. A systems-level framework to manage each factor could promote risk exposure assessment, monitoring, and management.

Conclusions

The current study identified that aging is a key driver of brain health. Similarly, cerebrovascular risk exposure that builds up biological damage in the brain needs strategic management to prevent irreversible damage that translates to impaired brain function.

In this regard, clinics providing brain health screening could be invaluable as preventive care services. They could screen at-risk but neurologically intact individuals concerned about progressing to dementia and other brain diseases.

Despite efforts to advocate for brain health, the concept is still evolving. Accordingly, a universal and easily accessible measure of brain health is not yet available, revealing knowledge gaps in the determinants and features of brain health.

It raises the need for public health campaigns and clinical studies among diverse populations exploring factors contributing to the evolving concept of brain health. Future studies should also quantify the effect of individual interventions and set priorities and allocate resources in areas with the highest brain disease burden.

In a nutshell, there are three pillars of brain health preservation, as follows:

1. Identify, manage, and monitor risk factors to alter the life-course trajectory
2. Systematic boost to healthy habits and behaviors that facilitate repair mechanisms; and 
3. Early risk stratification and targeted interventions to promote resilience against age-related pathologies.