Thought Provoking Question #6

           “The old man smiled.

                              'I shall not die of a cold, my son.

                       I shall die of having lived.” 

                                                       ― Willa Cather, 

                                                                                    Death Comes for the Archbishop

As Old As The Hills: Why We Grow Old and Die 

It’s better to be over the hill than under it, my grandmother use to say. Our slippery slope decline in life is further compounded by the anguish of its recognition. Although the gray mare ain’t what she use to be, at least she doesn’t know it. We humans are the only species that lives each day knowing that this day could in fact also be our last day. Being on the backside of forty, and the short side of time, no one is more aware of time, aging, and the grim reaper than me. But why do we grow old and die? First, I’ll give you the bad news, and in the next article, "The Golden Years: Good as New!," I’ll give you the good news. So don’t despair.  

So why do we age and fade? For starters, healthy elderly persons who do not develop any serious diseases eventually undergo irreversible fatal declines at about 100 years of age. In essence, death comes about in much the same way as an ancient barn house collapses under its own weight and the strong winds of time. Until the end of the nineteenth century, very few scientists spent much time on aging issues because they were trying to just figure a way to get people to midlife. It wasn’t until the early 1900’s when antibiotics and maternity care pushed the envelope of life into the sixth decade, that the science of aging, called gerontology emerged. Prior to the 1960s the belief was that it was the body that imposed the death sentence on body cells and therefore life. But biologist Leonard Hayflick declared the party over when he showed that cells divide and re-divide only finite amount of times and than die off. We’re kind of like tulip bulbs folks, the first few years they look great but each succeeding year they begin to whimper in the sunlight and finally fade into the still and dark. Scientists conclude that life is contingent on cell division. We now know that the lifespan of cells is genetically programmed and environmentally influenced. It’s the old "Nature Nurture" story, a question of form versus function. By age 75, more cells have died than been renewed. In fact cell counts declines by about 30%. Let’s take a look at what happens to some of the key body systems.  

The Skin System, which is really our space suit for life, begins to show age lines and age spots not from age itself, but from the constant bombardment of ultraviolet ra-diation. We know this by observing in the elderly, the difference between overall skin and buttock skin not exposed to sun. The process is akin to having a tired worn out Sunday suit. After awhile its frayed and tattered look give way to splits down the seam. 

Nervous System. At birth a baby is born with all the brain cells it will ever have. The newborn brain contains about 100 billion neurons, as many cells as stars in the Milky Way. From that point on they begin dying. The rate excels after age 30. When they die they are not replaced. By age 80, our brains weight about 7% less than they did in our prime. Some areas of the brain that handle higher cerebral cor-tex functions lose as much as 45% of their cells.  

Cardiovascular System. The heart is the only organ that grows bigger with age. Bigger, in this case is not better. Heart enlargement is a dangerous situation where cardiac muscle is replaced by fat. The heart loses bout 1% of its reserve pumping capacity each year after age 30. Other declines in this system are equally depressing.  

Respiratory System. As lung tissue ages, it becomes less elastic and less able to inflate and deflate. The lungs take in less oxygen, thus providing less oxygen for the vital red blood cells that depend upon it. This affects cough reflex and ability to clear lung mucus build up. In a sense we become like old inefficient gas-guzzling auto engines choking on our own fumes.  

Musculo-Skeletal System. Along with other system breakdowns, so too does this system decay, with osteoporosis and loss of bone mass continuing with age. The process is worse in women than in men. Drops in estrogen and human growth hormone levels affect both men and women. This process affects calcium levels, muscle decline, and bone mass. Sitting around doing nothing increases the loss of bone and muscle mass.  

Digestive System. This system seems to hold up the best, which is good and bad. It is bad because an efficient digestive system leads to fat build-up in an otherwise in-active body. The good news is that it works well enough to keep you alive. In other words you get to watch all your other systems break down as you age and get fat. Other problems include gallbladder and liver declines. These lead to gallstones and slow down in drug and alcohol metabolism.  

Immune System. One of the most noticeable declines in the immune system is in the thymus, a small gland in the neck, which seems to educate and regulate how T-cells coordinate a body’s defense against enemy microorganisms. The B-lymphocytes is another major cellular defense system. Its job is to attack with pincer-like molecules called antibodies. With age, they begin screwing up whom they actually attack. Often, like a drunken battleship sailor, the B-cells attack our own bodies, giving rise to such autoimmune diseases as arthritis. The ability to clone new T and B cells also deteriorates with age.  

Reproductive System. By middle age, a woman’s reproductive clock is fading fast. Her ovaries, which contain about two million ova at birth, have already dwindled down to about 400,000 by puberty. By age 50, most of these ova have been absorbed or shed, and only a few remain. Those that do remain are at high risk for genetic defects such as Down’s system. The sex hormones, estrogen, progesterone, and testosterone decline with age for both men and women. Sperm production declines in tandem with decreased testosterone levels, as well as in number and quality of sperm. Changes in hormone levels increases the prostate size in men, causing pressure on the urethra and making urination more difficult. The kidneys require more water to process and excrete waste and the bladder declines in capacity to hold this waste. For the most part, having a second bathroom moves from luxury to necessity.  

Sensory System. As we all most likely know from observing older family and friends, the five major senses dim with each passing decade like a dimmer switch on the down slide. It is a time of reading glasses, an age-related symptom called presbyopia, from the Greek words "elder eye." Our hearing fades due to loss of nerve cells conducting signal passage. First to go are the high-pitched ranges fol-lowed by the low-pitched ranges. Taste buds in our gustatory receptors trail off making extreme taste-range treats like ice cream and chocolate elderly favorites, though these taste extremes may also affect elderly digestion as well.  

So what are we baby boomers to do? Give up, curl up, and dry up like prunes in the sun? Actually, there is much we can do to grow gracefully into our tomorrow’s. In the next article, we’ll cross over that old as the hills landscape and catch a glimpse of where the grass is always greener and younger. Come with me to "The Golden Years: Good As New."  

[References: Much of the data source on bodily system decline was found in: Merz, B. (1992, October). Why we get old. Harvard Health Letter. Cambridge: President and Fellows of Harvard College, pp. 9-12; McCue, J. D. (1995), and The naturalness of dying. Journal of the American Medical Association, 273, 1039-1043.  

Miller R. A. (1994). The biology of aging and longevity. In: Hazzard W. R., Bierman, E. L., Blass, J. P., et al, (eds.). Principles of Geriatric Medicine and Gerontology. (3rd Ed.). Boston: McGraw-Hill, pp. 3-18.  

Nash, M. J. (1997, February 3). Fertile minds. Time.  

Schmidt, K. F. (1993, March 8). Old no more. U. S. News & World Report, pp. 66-70.] 


This article is by Dr. J. Davis Mannino and originally appeared in the community newspaper We The People. All Rights Reserved by the author.