Aging is associated with changes at multiple levels – biological, physiological, environmental, psychological, behavioral, and social processes. Some age-related changes are benign, such as graying hair. Others result in declines in function of the senses and activities of daily life and increased susceptibility to and frequency of disease, frailty, or disability.

The biology of aging and its impact on the prevention, progression, and prognosis of disease and disability

Advancing age is the major risk factor for developing many major chronic diseases. Conversely, many diseases accelerate the aging process, manifested as declines in functionality and reduced quality of life. Aging itself is the primary risk factor for neurocognitive impairment such as  Alzheimer’s Disease and most other forms of dementia, as well as diseases and conditions that are associated with increased dementia risk such as type 2 diabetes, hypertension, and vascular disease. Research shows that aging-related changes influence the brain and increase vulnerability to pathological change. Dementia is not a normal part of aging; however, it is observed in a substantial portion of the aging population. At the age of 65, an individual is at a 4 percent risk of developing dementia. Every 5 years, the risk doubles such that, at 85 years of age, an individual has a 45 percent risk.

Researchers continue to identify and explain key factors affecting the rate of aging, including the body’s response to a variety of stresses, the function of the immune system, the role of cellular deterioration, the body’s response to damage to large molecules such as proteins or lipids, and protein quality control. Studies of genes and epigenetic mechanisms associated with aging processes, longevity, and age-related diseases, as well as the interplay among genes and environmental influences, also continue to provide insights into disease pathologies and vulnerability.

While there is no single “key” to explain aging, research studies have demonstrated that the rate of aging can be slowed, suggesting that targeting aging will coincidentally slow the appearance, reduce the burden of numerous diseases, and increase the portion of life spent in good health.

Mobility changes in the aging adult can result from changes in gait, balance, and physical strength, and can negatively influence the number and severity of falls, social participation, and independence. Loss of sensory functions such as vision, hearing, or the ability to taste is also common among older adults.

The effects of personal, interpersonal, and societal factors on aging

Behavioral and psychological factors such as physical activity, smoking and other health behaviors, cognitive and social engagement, personality, and psychosocial stress play a critical role in health across the lifespan. Studies have shown that up to 50% of preventable deaths in the U.S. can be attributed to adverse health behaviors such as smoking, alcohol consumption, and an unhealthy diet that results in obesity. Social factors such as social relationships and socioeconomic circumstances have a similarly important impact on health and well-being. For example, subjective feelings of loneliness are known to be a risk factor for serious functional declines and even death, and evidence from multiple cross-national epidemiological studies indicate that social isolation is a major risk factor for morbidity and premature mortality. Additionally, the relationship between personality, which is the stable individual differences in dispositions to think, feel, and act in particular ways, and aging-related outcomes has been well documented.

Furthermore, we now know that behavioral and social factors interact with genetic, molecular, and cellular mechanisms to influence health at older ages. Basic behavioral science is uncovering individual-level psychological, social, and behavioral factors that predict adaptive and healthy aging or confer risk for age-related decline. Evidence suggests that addressing these factors and their interplay are critical to minimizing disease and achieving full potential and vitality as people age.

Along with new physical, social, and emotional challenges, increasing age brings changes in cognition and emotion that have impacts on subjective well-being, social relationships, decision making, and self-control. How individuals respond to these challenges has implications for their independence, cognitive function, social relationships, mental health, physical function, and economic well-being.

Many outcomes and behaviors in older adults are influenced by events, social relationships, noncognitive character skills, environmental factors, and habits that begin early in life. Exposure to adverse social, interpersonal, and physical environments can exert profound and long-lasting psychological and physical effects on an individual, with long-term impact on adult physical and cognitive health and longevity. Contextual factors such as residential segregation and socioeconomic status may be associated with or compound the effects of these adverse exposures, and patterns of stress reactivity hasten the progression of disease.

As the population ages, it will be important to understand how people make decisions about retirement, lifestyle, social relationships, health, and health care. Age-related changes in the interplay between motivation, cognition, and emotion, along with changes in life circumstances, health status, and social roles, combine to shape how individuals make both everyday choices around health behaviors and major decisions related to life transitions and long-term goals. The ability to make sound decisions is a critical component of cognitive health, and deficits in decision-making abilities may be an early warning sign of dementia.

Sources:

• National Institute on Aging (NIA)
• Abilities Behavior Services