The Evolutionary Theory of Aging: Do Genes Drive the Process

Delineation of how humans are changed by aging processes

The aging process is complex and multifactorial, but in simplest terms can be thought of as cumulative changes in an organism, organ, tissue, or cell through our lifespan, leading to a decrease in functional capacity. It is associated with degenerative changes in the skin, bones, heart, vessels, lungs, nerves, brain, and all organs. Much of this aging process is governed by genetics, which is largely responsible for how we age. However, how well we age can be controlled to some degree in the choices we make about how we live our lives. Even with a bad genetic roadmap, all is not lost!!

My interview subjects in general agreed that changes as they age become more pronounced over the years, and they all agreed with that famous saying: Growing old is not for sissy’s. For my interview subjects, I attempted to provide a guided survey to provide categories into which typical aging progression can be recognized. These were grouped into physical, psychological, and social aspects of aging. As was discovered, the physical & psychosocial aspects of aging are closely related. A reduced ability to respond to stress, the experience of multiple losses & the physical changes associated w/ normal aging combine to place people at high risk for illness & functional deterioration

The more we learn about aging, the more it appears to be something that does not have to equal suffering and illness. Through both luck but also careful lifestyle choices, we have the ability to not long live long but live well.

While genetics do indeed play a role, we’ve learned throughout this course that we have more control on the aging process: both from a quality as well as a quantity perspective. Different views of aging certainly are presented, amount scientists and experts. Does aging follow a purposeful pattern driven by genes? Does it happen through random coincidental events? Really, in simplest terms, aging is the progressive and inexorable accumulation of molecular and cellular damage, which leads to loss of physical function, increasing infirmity, elevated risk of chronic illness, and ultimately death.

According to the evolution theory, all biological processes are genetically programmed from the beginning of life to reproductive maturity. Beyond this point, studies are in disagreement as to whether genes further drive the organism into aging or whether aging stems from a stochastic accumulation of damage affecting cells and organs over time.

One of the most notable aspects of aging is that our bodies change in ways that don’t seem to be entirely under our control. The reality is most organs function less well as we people age because as we have learned throughout this course, our cells lose their ability to replicate and replenish.

For example, it seems that one of the first and most difficult signs of aging involves the musculoskeletal system. Physical difficulties that begin to affect us as we age, involve our mobility. Our bones get less dense, our muscles weaken and our joints stiffen. By age 75, the percentage of body fat typically doubles compared with what it was during young adulthood. Too much body fat can increase the risk of health problems, such as diabetes.

Decreasing mobility due to balance issues, pain, stiffness, and weakness is especially emotionally trying for elderly individuals. Each of these problems is important to understand as they impact quality of life and emotional well-being. Having these problems, along with others to follow, remind us that we are getting older, manifested in undesirable ways.

As we age hearing and sight often decline. Trouble hearing can be especially frustrating to the elderly and to those around them. The ability to hear impacts speaking and equilibrium, so a person who has trouble hearing may also have difficulty speaking, and feeling off balance or dizzy. According to the National Institute on Aging, “hearing loss occurs in approximately one in three people age 65 to 74, and nearly one in two people age 75 and older”.

One troubling aspect in regards to hearing loss is it may impact cognition and increase dementia risk in older adults. A funded National Institute in Aging study found that hearing loss contributed to the development of dementia at greater rates than the elderly with normal hearing. In fact, according to this study, uncorrected hearing loss was the contributing factor where “mild hearing loss was associated with a two-fold increase in risk; moderate hearing loss with a three-fold increase in risk, and severe hearing loss with a five-fold increase in risk”.

Another study showed a correlation between hearing loss and accelerated decline in both cognition and memory. 

Vision may also decline for the elderly. While none of my interview subjects reported age-associated vision decline, it is very much a reality for many people. This can affect many previously enjoyed activities, such as reading, watching television, or driving.

Additionally, we are burdened with a host of potential chronic diseases as we age. Heart disease and stroke, diabetes, cancer, and arthritis all seem to become a reality of our aging body and its inability to respond to stressors, resulting in illness and death.

There are different studies that examine what causes memory impairment

Interestingly, aging seems to not always have a significant direct impact upon our brain by direct cellular loss but instead can be a result of a disease that is chronic in nature such as atherosclerosis, which decreases blood and oxygen flow to the brain. According to Marsha K. Johnson, Yale University, our frontal lobes are in large part responsible for our memory recall. Being able to process information and then tie experiences together is imperative for the memory to become entrenched. Damage to this area of the brain, if significant enough, will impair functioning and potentially cause dangerous deficits.

Finally, our ability to fight off illness and stay healthy is largely due to our immune system. But as we age, even our immune system can become weak and stop protecting us like it used to. Our immune system begins to work slower, and autoimmune diseases may develop and even the healing process becomes impaired. Our weakening immune system thus, is yet another way in which we lose our ability to fight environmental stressors, leading to more incidents of acute and chronic disease that are often associated with getting old.

Reports of interviews with aging persons about how biological aging has impacted their lives

Interview Subject 1:

• Age – 55 years old
• Ethnicity - caucasian
• Residence - California, rents does not own home
• Gender - Male
• Income - $70,000+ per year
• Occupation – City Planner
• Education – Master’s Degree
• Marital Status – Single; Never married

My first interview involves a 55-year-old male who lives in California and is engaged in the same profession as a City Planner, although he is seeking to retire early. While he remains physically active as a bicyclist, he admits to a terrible diet, is addicted to sugar, and is therefore overweight. He has never married and has had a variety of stressful life events in the past few years.

When asked what he perceives to be his health state and pattern of aging, he says he has noticed that after entering his 6th decade of life, poor lifestyle choices have a bigger impact and he sees the effects. He notes his hair is graying and much thinner and that he is balding on top. He also admits to having more difficulty in keeping his weight down, which was not as difficult even with a poor diet, in his earlier years. He says he can say that he has that middle age spread and is quite frustrated by it. He wears glasses but says his eyesight has always been poor, and he has not noticed any significant decline. He reports to experiencing some hearing loss but admits that it is most likely due to listening to loud music with earbuds frequently.

Remaining physically active throughout his life, he believes his heart and lungs remain strong for his age, although he reports anxiety over stroke and diabetes given his family history of both. He does notice as he ages he is less excited about doing long hard climbs on his bicycle, but states that part of that might be due to being overweight as well.

His skin is wrinkling, but again he admits to part of this being due to sun exposure as well as aging. He realizes he could make better lifestyle choices in many different areas, to ensure better physical health and aging. Cognitively he believes he is fairly normal for his age, with mild amounts of forgetfulness with simple things like where he parked the car, or forgetting something at the grocer. He is not alarmed at any unusual rates of cognitive struggles but realizes it could very well happen to him and it is frightening.

My subject admits to a high level of anxiety and stress due to poor lifestyle choices, and what that will mean for his health and well-being as he ages. He states that he would classify himself as feeling older than his chronological age due mostly to lifestyle choices, that he is constantly aware of getting old and he is beginning to feel the effects of his choices and his age in everything he does.

Emotionally, he admits to being stressed out and worried about aging. He often jokes around about stockpiling “little death pills” to avoid the realities of getting old and not having children and having no desire to enter into any senior living environment. He tries to remain engaged, but overall admits to being somewhat anti-social, while not attributing it to aging. He does not enjoy his profession and wants to retire early.

He sees the impending loneliness and isolation often seen in our most elderly people, and fears being in a wheelchair, sitting in some nursing home hallway, neglected and forgotten. He is not taking the aging process well, nor does he seem very hopeful of a fun and engaging life as he continues to age.

Interview Subject 2:

• Age – 78 years old
• Ethnicity – Caucasian/Asian
• Residence – Anacortes, WA; Owns home
• Gender - Female
• Income – retired, $2000 per month Social Security
• Former Occupation – variety of work
• Education – College graduate
• Marital Status – Married, husband in Assisted Living
• Children – 2 boys, grown and living out of state; 1 girl, local

My second interview involves a 78-year-old female who lives in Washington State and is retired. She held a variety of work positions mostly in retail and restaurant. She’s actually quite amazing, remaining physically active through bicycling and hiking, and loving the great outdoors and recreation the state of Washington offers.

When asked what she perceives to be her health state and pattern of aging, she says he has noticed that remaining of positive spirit and physically active has translated into wonderful senior years. She does state that she notices her hair is graying and much thinner but she keeps it cut short and sees it as an inevitable part of aging. She does not see a need to disguise it through coloring. She admits to having more difficulty in keeping her weight down, but states a healthy diet and exercise goes a long way and she does not stress over it, nor struggle with obesity. She wears glasses and says she does notice her eyesight has deteriorated in the past five years. She is happy to report that she has not experienced any significant hearing loss.

My subject is an avid bicyclist and hiker. She states that not only does it help her physically, but also emotionally. She notices much less depression than her peers because she remains active and fits into her 70s. She loves where she lives and is enthusiastic about the great outdoors. She notes that it is her form of therapy and wishes to keep active as long as she possibly can, noting that her physical health remains strong due to exercise. She states that she does experience occasional stiffness in her joints, but believes in the old adage of “use it or lose it”. She believes her physical decline would accelerate if she did not keep up with her hiking and biking. She participates in several local hiking groups, which she notes keeps her going and also provides great socialization and wonderful support.

She reports what she feels is a normal amount of skin aging with wrinkles and a few age spots, and believes being outdoors in the summer has accelerated this aging. She believes that being in Washington State may be her saving grace, and the cloud cover half the year along with being in tree-covered forests has possibly slowed her skin aging.

She thinks about and believes she could make even better lifestyle choices in many different areas, to ensure better physical health and aging. She states that she does love fried foods and the occasional beer, and that is her weakness. Laughing, she notes that she hikes for fries and beer!

Cognitively she believes she is above average for her age, noting no family history of Alzheimer's or dementia. She does see mild amounts of forgetfulness, but states it is more the result of not paying attention and really recalling facts or situations. She does not express concerns over “losing her mind” in the future.

Emotionally, she admits to being stressed and worried, not about aging, but about her husband in Assisted Living. She says it is a major stressor in her life, watching as he slowly declines and needs more and more assistance. She does not feel the care is very comprehensive where he is and feels guilty and responsible for him. She seeks out support groups, and that has eased her burden.

Socially, she is a free and happy spirit. She is very involved in the community through volunteer work, sees her daughter regularly, and has a variety of friends with many interests. She notes that she rarely feels lonely or alone, and believes this will remain a fact through the rest of her life. She continues to enjoy life immensely, and believes she can reach that magic 100 years!

My subject number two is overall a wonderful example of healthy and positive aging, and I learned so much from her!

Interview Subject 3:

• Age – 87 years old
• Ethnicity – Caucasian
• Residence – Oak Harbor, WA; Memory Care home
• Gender - Female
• Income – retired, $2000 per month Social Security
• Former Occupation – a variety of work
• Education – High School graduate
• Marital Status – Married, 3rd husband in Assisted Living in Fort Wayne, IN
• Children – 2 boys, grown and living out of state; 1 girl, local

My third and final interview subject is of course, my mother. This was a much more guided interview given the fact that she does have dementia, yet remains capable of talking and answering questions and being interested in her life story. She is an 87-year-old Caucasian female living in Memory Care in Oak Harbor, WA.

I would classify her as early middle stage in the disease process, although no formal diagnosis has been made. She of course is retired, having held a variety of jobs throughout her life. She reports that her favorite job she had was being a telephone operator in her younger years. She even remembers her operator number of 29. She says she did a variety of different jobs throughout her life and into her senior years, including child care, and mowing lawns, and smiles big when talking about the newspaper routes that she walked even in knee-deep snow and below-zero cold winters.

When asked what she perceives to be her health state and pattern of aging, she states that she is getting old! She also reports to having a lot of leg pain and believes nothing can be done about it, that they have always hurt. She says the surgeon that replaced her knees ruined her legs. She loves to walk but states that it is much more difficult now due to her legs hurting. She says she tries to remain active and get up and about when possible. She states that she now needs the help of a walker to keep moving, but does not feel bad about it.

Another very interesting note with this subject is that she recognizes that her memory is not fully intact. She states that she does not always remember things, and then points to her head and says “boom” like her mind is gone. It’s heartbreaking. She repeats again that she is getting old. She says she needs help with dressing and going to the bathroom and getting her shower. She still states that she wants to go home and could manage just fine, even mowing the lawn.

My subject also made comments about her hair being white and much thinner. She says she is very unhappy about this, as her hair is very important to her. She does state that she loves to have her hair washed and blow-dried.

Subject three also admits to significant hearing loss and attributes it to her lawn mowing and working in the kitchen. She wears hearing aids. She also says she is able to follow along with television shows by reading the captions, and says she loves wheel of Fortune and family feuds. However, she does admit that hearing loss is very frustrating and depressing, as she is unable to engage much in normal conversation. Communication becomes more fruatrating and, after time, she avoids trying to start a conversation, and resorts to answering questions if necessary.

Additionally, this interviewee states she feels less thirsty and hungry. She does partake in water through encouragement but admits to enjoying breakfast but no other meals. She states she is a much better cook. So it appears that thirst and hunger sensations have declined with age for this subject.

She does report that she is often tired or bored or both. She admits to enjoying the attention from staff (especially the one male caregiver, whom she says is cute and she wants to take him home). However, throughout our interview, she repeatedly stated she was good enough to go home, and did I come to take her home. She is able to recognize me as her daughter and says I look just like her. She says she enjoys remaining playful with a couple of the residents, but she still wants to go home. She denies any major depression, only being tired and at times bored. She remains kind, which is a major plus in her current environment, which is helpful to both her spirit, to other residents and overall impact on her continuing aging process.

Analysis of the effects of biological aging on a person's functional independence

There is no doubt, aging can and does have an impact on the quality of life for human beings.

Exactly what constitutes normal aging is not always clear. For example, normal, nuisance memory struggles seem to be the result of aging. Severe cases where significant life experiences and/or lost ability to identify loved ones are not normal aging. Memory impairment that creates issues of safety often leads to the need for alternative long-term care.

As was noted by my interview subject number three in particular aches no longer come and go, they come and linger. For her, the aches include severe pain that is a constant companion. Aging both physically and cognitively means she is no longer functionally independent. She needs 24x7 supervision, and help with all Activities of Daily Living. This places a heavy emotional burden on her, despite having cognitive decline, she is well aware of where she is and the help that she needs.

As we have learned within this course on aging, normal aging should mean a slow decline in the loss of physical and social function. Suicide among the elderly and ill is a very real risk. For reasons we don’t fully understand, older adults are committing suicide. In increasingly larger numbers. We should be worried, really worried, about what this trend means. We need to find a way to take better care of our elders. I found a fantastic depiction in regards to what it is like to be old, designed to build empathy for the elderly in our society. It is entitled What Is it Really Like to Be Old? Can we truly be empathic about the elderly experience? The author detailed a host of experiential exercises designed to simulate lost function as one becomes elderly and frail.

She notes the following in regard to the exercises:

First, all of us were instructed to place earplugs in our ears. Following that, we were instructed to put popcorn kernels in our shoes. Right from the start, we were supposed to imagine being hearing impaired with simulated peripheral neuropathy in our feet. We started with a mobility experience. In addition to not being able to hear much or walk well, we were instructed to wear gloves that would also simulate neuropathy (numbing), in our hands. We were given bands to place around our ankles, to mimic impaired walking. Finally, we were given glasses that simulate all of the various eye problems that can occur with aging and illness. My glasses seemed more benign than what my colleagues were wearing; I had no peripheral vision—a common problem of old age and elderly eyes. Then, given a cane, I was asked to walk down the hall. It was maybe 100 feet. I was pretending to be an elder with impaired hearing and vision, bad mobility and numbness in my hands, and pain in my feet. I realized that I was not sure that I could actually complete the walk down the hall. Suddenly, my class exercise did not feel like a game. I started to panic. From the loss of peripheral vision, I could not see who was standing next to me, and I started to feel suspicious. As I walked, I had a lovely young woman at my side (I was lucky, she is a physical therapist in real life), who could help me if I needed it. I did not want help, however; I wanted out of my body, which felt trapped, alone, and isolated. Weirdly, even though we were pretending, I felt mad at my companion, who had a body that worked so much better than mine. It was at this moment I understood something in a way that I never had before. I thought I might kill myself if I had to live this way. 

As we can all certainly learn from her experience, many of the associated problems we face as we age start to define our lives and overcome us physically and emotionally with both the fear of dying and the loss of health and activities. We as future gerontologists need to be the experts in how we understand the impacts upon a person's functional independence can to a decline in quality of life. Do our clients still feel like they have a purpose and enjoy meaningful activities? Is depression a major concern? What is their overall loss of functioning, and how it is going to affect them in the future?

Societal Effects of biological aging

I identified three main impacts of an aging population, notably tied into financial burdens

1. Increase in dependency If the retirement age remains fixed, and the life expectancy increases, there will be relatively more people claiming benefits and fewer people working and paying income taxes.
2. Increased government spending on health care and pensions. Also, those in retirement tend to pay lower income taxes because they are not working. This combination of higher spending commitments and lower tax revenue is a source of concern for Western governments – especially those with existing debt issues and unfunded pension schemes.
3. Shortage of workers. An aging population could lead to a shortage of workers and hence push up wages causing wage inflation. Alternatively, firms may have to respond by encouraging more people to enter the workforce, through offering flexible working practices.

Growing older scares us for a variety of reasons. Some of us can’t imagine being dependent. Others just want to be able to exercise like we did when we were in our youth. Even more so, the societal impact of an aging population cannot be ignored. As our healthy life spans increase there are certainly benefits for the individual, yet the problems it brings at the family, community, and national levels can be immense.

According to the National Institute on Aging, “We are aging – not just as individuals or communities, but as a world. In 2006, almost 500 million people worldwide were 65 and older. By 2030, that total is projected to increase to 1 billion – 1 in every 8 of the earth’s inhabitants”. Such statistics are mind-boggling, and present opportunities along with unmistakable challenges. (8)

As this aging population in our country grows, the cost of aging in America will grow, too. The cost of healthcare is increasing not only due to the fact that people are living longer, but they are also living with chronic conditions that will need attention and care. As people age, they suffer from more and more illnesses. These chronic illnesses are placing an increasing burden on health systems. Governments need to recognize the effects of demographic change, not merely on public services, but on the social climate as well. An aging population can also create an unsustainable burden at the household level. The physical and emotional burden of providing care to an aging loved one is compounded by the financial burden as well. As family takes on more of the responsibility of caring for the nation’s growing senior population, their own personal and professional lives often pay the price. Beyond the hours they spend caregiving, many pay for caregiving costs out of their own pockets,

In other words, the growing elderly population places ever-increasing stress on an already over-burdened senior care system. The demands associated with long-term care might pose the greatest challenge for both personal/family resources and public resources. According to the CDC, “in the United States, nursing home and home health-care expenditures doubled during 1990—2001, reaching approximately $132 billion; of this, public programs (i.e., Medicaid and Medicare) paid 57%, and patients or their families paid 25%”. The expected increase in the number of older persons will have dramatic consequences for public health, healthcare financing and delivery systems as well as informal caregiving. As the worldwide population ages, the healthcare systems will face significant challenges to meet the needs of an aging population. Elder and long-term care is rapidly becoming one of the largest healthcare challenges of our day.

The economic effects of an aging population are considerable. Societies must learn to control these costs through significant investment into public health programs designed to promote healthier living so our populations begin to age more gracefully and focus on quality versus just extending our lifespans. Because behaviors that place persons at risk for disease often originate early in life, the public health system should support healthy behaviors throughout a person's lifetime. Public health also should develop and support better methods and systems to monitor additional health outcomes that are related to older adults, such as functioning and quality of life.

Conclusion

As Americans continue to live longer, becoming a senior at age 65 is no longer considered a major watershed in a person's life. Many people are continuing to work beyond age 65 because they are healthy and productive and do not wish to spend the rest of their lives watching television at home or playing golf or traveling. However, at some point, the aging process catches up with all of us. For a few of us, it occurs well before the age of 65, but many of us can remain healthy and productive well into our 80s and even 90s.