Chiropractic + Naturopathic Doctor • June 2020 • Life and longevity

People are living longer and healthier lives, representing one of the crowning achievements of the last century. Living longer also boasts a significant challenge: Longer lives must be planned for. The Global Burden of Disease, a study conducted by the World Health Organization and the World Bank, with partial support from the U.S. National Institute on Aging (1), predicts a very large increase in disability caused by increases in age-related chronic disease in all regions of the world. In a few decades, the loss of health and life worldwide will be greater from non communicable or chronic diseases (e.g., cardiovascular disease, dementia and Alzheimer’s disease, cancer, arthritis, and diabetes) than from infectious diseases, childhood diseases, and accidents.

Globally, the population aged 65 and over is growing faster than all other age groups. According to data from World Population Prospects: the 2019 Revision, by 2050, one in six people in the world will be over age 65 (16%), up from one in 11 in 2019 (9%). By 2050, one in four persons living in Europe and Northern America could be aged 65 or over. In 2018, for the first time in history, persons aged 65 or above outnumbered children under five years of age globally. The number of persons aged 80 years or over is projected to triple, from 143 million in 2019 to 426 million in 2050.(2). According to Statistics Canada, Canadians are living longer and seniors are on track to represent about 25% of the population by mid-century(3). Health care costs will also be a burden on the government, as seniors utilize 4.4 times more compared to the younger population.(4).

The aging population has unique characteristics, which are shown below and summarized from the American College of Sports Medicine (5):.

Muscle Strength and Power – Isometric, concentric and eccentric strength declines after age 40 and accelerates after age 65-70. Lower body strength declines faster than upper body strength. Power declines faster than strength.

Muscle Endurance and Fatigability – Endurance declines. The effects of age on mechanisms of fatigue are unclear and task-dependent.

Motor Performance and Control – Reaction time increases. It takes longer to react. Speed of simple and repetitive movements slows. Complex tasks are affected more than simple tasks.

Flexibility and Joint ROM – Significant decreases in hip, spine and ankle flexion by age 70. Muscle and tendon elasticity decreases.

Cardiac Function – Maximal heart rate, stroke volume and cardiac output decline.

Blood Pressure – BP at rest increases. BP during submaximal and maximal exercise is higher in old vs young, especially in older women.

Ventilation Chest wall stiffens. Expiratory muscle strength decreases. Work of breathing increases.

Gas Exchange – Reduced surface area for gas exchange in the lungs due to loss of alveoli.

Maximal O2 Uptake – Declines about 9% per decade in healthy sedentary adults. Rate of decline accelerates with advancing age.

To have a better understanding of how an aging person transitions to a person with disabilities, we need to become familiar with the Nagi Model.(6).

The first disablement model was introduced in 1965 by Saad Nagi (6). He recognized the importance of the environment and that family, society, and community factors could all influence disability. Based on this assumption, the consequences of disease and injury for an individual should be described at both the level of the person and at the level of society:

Later, it was modified to include Lifestyle Inactivity, which also impacts Impairment. Let’s expand on each of these headings for understanding and clarity:

Disease Pathology may include such health issues as diabetes, obesity, cardiovascular disease, cancer, neurological diseases eg. (Parkinson’s, Multiple Sclerosis), osteoporosis and osteoarthritis, etc.

Lifestyle Inactivity including been sedentary, sitting most of the day, alcohol use, smoking, decreased sleeping and poor diet.

Disease Pathology and Lifestyle Inactivity contribute to the development of impairment.

Impairment issues can begin to express themselves as decreased muscle strength, power, endurance, decreased cardiovascular and respiratory function, decreased flexibility/range of motion of the spine, hips, knees and ankle joints, decreased speed of mobility and reaction time.

Functional Limitations may lead to decreased ability to stand up from sitting, slow walking, difficulty climbing stairs, decreased long term standing, cooking, decreased ability to grasp objects, open doors, unstable balance and carrying bags. All of these limitations can contribute to decreased mobility and social interaction, contributing to anxiety, depression and being lonely.

The more Impairments there are, the more or severe the Functional Limitations. The Functional Limitations contribute to Disability.

In summary, variance of disability can be accounted for by functional limitations, disability and age. Age can directly influence disability, through its effect on functional limitations and its inherent disability. Given our aging population, there’s great interest in identifying modifiable risk factors for cognitive decline. Studies have highlighted the relationship between aspects of mobility and cognitive processes. However, cognition and mobility are both multifaceted concepts and their interrelationships remain to be well defined.

In one study, Steinman(7) showed that individuals with poor vision had significant difficulty doing leisure activities at home. Poor vision will affect mobility, reading, watching TV, cooking and socializing. With poor vision people begin to get anxious regarding their capabilities and limit their interactions with family and friends. Poor vision also contributes to cognitive decline.

Li (8) suggests that the cognitive involvement in postural control and gait increases with aging. This happens because of the neural overlap of cognition and some brain areas which are related to the aging process. Posture and gait are complex activities which encompass large areas of the brain. To maintain good posture entails our visual, vestibular and cerebellar (somatosensory) systems, along with the neuro muscular junction and the long tracts taking information to and from the brain. Gait involves additional areas, as gait involves initiation of and rhythmic movement. This involves the motor Cortex and Basal Ganglia as the main areas for understanding.

Demnitz(9) found that all cognitive measures were related to indices of mobility, suggesting a global association. Mobility affects all aspects of our lives. Movement affects all our body systems, from our joints, the cartilage between, the blood supply, the nerve muscle interaction, our lifestyles and our ability to function as human beings. Movement is part of our personality make up, and because it is so pervasive to us being human, it is now been used to help diagnose health conditions. As we age our movement patterns change, and these changes affect our body and brain, because they are so interrelated, contributing to this issue of cognitive decline.

Wanigatunga(10) found that daily physical activity, which benefits health and quality of life, typically decreases in older adults. We all need to be more physical and we need to specifically encourage our aging population to incorporate physical activity into their lifestyles. As an example, physical activity causes muscles to move. As muscles move, they function better and there are feedback mechanisms between muscle and bone, which help both to function better. Physical activity improves circulation to all parts of the body and the brain. With a good diet and physical activity, more nutrients will get to the muscles, body systems and the brain, to improve the quality of life of the individual.

Gaskin(11), stated that the burden of neurological disease is expected to increase as the population ages. This burden that we as a society face can be significantly decreased if we provide for and encourage our aging family and friends to be more active, eat well, exercise more and spend time with family and friends. The purpose of this and following articles is to help us look after ourselves, our family, our patients and our friends.

DR. DON FITZ- RITSON is a chiropractor and a Rehab Specialist. He was an Assistant Professor at CMCC. He published 17 papers and 3 chapters on chiropractic.He co-invented a laser and it received 7 Health Canada Approvals. He is focused on helping the aging population live better lives.