How the Body Changes with Age – Conversations to Remember

The cell is the smallest self-sustaining component of a living organism. Cells can independently divide, grow, synthesize molecules, generate energy, and respond to environmental cues. In more complex organisms, such as humans, cells performing similar functions are grouped into tissues, which subsequently make up the key organs and organ systems of the body. The most vital organs in the human body include the brain, heart, lungs, kidney, and liver; the cells that make up these organs are specialized in terms of shape and function. For example, neurons, which are types of brain cells that conduct signals related to sensation, movement, and other involuntary functions, can be over a meter long! In the heart, cardiomyocytes are more compact, rectangular-shaped cells that closely connect with neighboring cells to ensure the heart beats at a regular rhythm.

While the entire aging process is not fully understood from a scientific standpoint, researchers have proposed two theories: The first theory suggests that the effects of aging are driven by an accumulation of byproducts from the body’s natural metabolism, which causes widespread and irreversible abnormalities in cells. Another theory posits that the cause is a progressive loss in cells’ regenerative abilities. The latter process occurs when telomeres, the noncoding, repeated sequences at the end of chromosomes, are lost with successive cell divisions. Once telomeres are sufficiently shortened, the cell enters senescence, where it retains its metabolic functions but permanently stops dividing. Cell division is necessary to repair damage, replace old cells, and promote organism-wide growth. When the rate of cell division decreases and senescent cells build up, organ systems start to slow, and the aging process begins.

Aging appears as a series of physical appearance changes. We observe parents, grandparents, aunts, and uncles slowly develop more wrinkles and gray hairs compared to when we saw them last. They may appear to get shorter as we grow older, but even this is no coincidence. As people age, the spongy disks between spinal vertebrae dry out and lose their volume, causing the spine to compress and people to “grow shorter.” Other recognizable hallmarks of aging include signs of forgetfulness and the development of hearing loss and farsightedness.

In addition to these observable aspects of aging, changes in our internal organs also contribute to the body’s gradual decline. For instance, in the brain, neurons decrease in number and nerves conduct signals more slowly, causing individuals to take longer to remember certain words or to have difficulty multitasking. Even though all these components are a normal byproduct of aging, they may be symptoms of chronic health conditions, such as dementia, if memory or cognitive decline start to interfere with daily activities and independence. In the cardiovascular system, blood vessels become stiffer, and the heart needs to work harder to pump blood to the rest of the body, increasing the risk of hypertension and other cardiac conditions, including congestive heart failure and stroke. Additionally, the bladder loses its elasticity as the muscles that control it weaken, leading to urinary frequency, loss of bladder control, and difficulty emptying the bladder. In general, muscles lose strength, and bones become more brittle, increasing the risk of injury and an overall decline in fitness. This results in a higher risk for falls, as these muscles and bones stabilize articulations between joints and are important for flexibility, coordination, and balance.

There are many actions that individuals can take over their lifetime to reduce the risk for some of the aforementioned conditions and symptoms. Healthcare professionals recommend maintaining a regular level of exercise, eating a healthy diet, and participating in activities that challenge the mind. Crystallized intelligence, which is the combination of skills and knowledge learned over one’s lifetime, even increases with age as one gains more life experience. Professionals also suggest receiving vaccines on time and participating in yearly screening tests. With the risk of cancers at older ages, screening tests can detect diseases at early stages and allow the individual to start receiving treatment before the disease spreads or progresses.

Currently, the average human lifespan is between 70 and 80 years. New advancements in healthcare and awareness of what it means to live a healthy life have helped alleviate worries related to aging. Aging should be a positive process, especially when we start to anticipate the good memories, friends, and places we will discover in the near future.

Sources: