Aging is a process that happens your whole lifespan. When you're younger, aging is associated with growth, maturation, and discovery. But somewhere along the timeline of your life, you begin to experience changes that are signs of deterioration or decline.
 Some changes are not necessarily harmful. With age, your hair thins and turns gray. Your skin thins, becomes less elastic, and sags.
Other changes lead to loss of function of bodily organs. In the gastrointestinal system, for example, production of digestive enzymes diminishes, reducing your body's ability to break down and absorb the nutrition from food.
When Does Aging Begin?
Gerontologists (people who study aging and the problems of the aged) use a precise term – senescence – to describe the progressive deterioration of many bodily functions over time. But when does that aging process begin – at birth or after retirement? Perhaps it begins at conception? Or does aging begin at age 20, or 40, or 75? And what causes aging? Are humans programmed to age at a certain pace, or is it a hazard of living? Gerontologists are still arguing about the answer.
Since 1958, investigators have tracked the lives of more than 1,000 people from age 20 to 90 and beyond to determine what normal, physiological aging is, and to determine when senescence begins. The Baltimore Longitudinal Study of Aging (BLSA) shows that people age at different rates, and that they also age in different ways.
Most scientists theorize that aging likely results from a combination of many factors. The BLSA suggests that genes, lifestyle, and disease can all affect the rate of aging.
What's Affected?
What's likely to go first – your mind, your hearing, your physique, or your heart? In some individuals, kidney function might be the first to go. For others, bone strength might be affected first. According to the National Institute on Aging, some generalities can be made regarding what aging does to your body.
Arteries: Your arteries stiffen with age. Additionally, fatty deposits build up in your blood vessels over time, eventually causing arteriosclerosis (hardening of the arteries).
Bladder: You have to urinate more frequently. More women than men experience urinary incontinence.
Body Fat: For typical Americans, body fat increases until middle age, stabilizes until later in life, then decreases. The distribution of fat shifts – moving from just beneath the skin to surround deeper organs. Abdominal fat increases the risk of heart disease and other conditions.
Bones: Somewhere around age 35, your bones lose minerals faster than they are replaced.
Brain: Your brain loses some of the structures that connect nerve cells, and the function of the cells themselves is diminished. "Senior moments" increase.
Hearing: Your eardrums thicken, while the ear canals thin. Overall, you have a harder time hearing higher frequencies as you get older, as well as difficulty hearing when there's background noise.
Heart: Your heart is a muscle that thickens with age. Your heart's maximum pumping rate and the body's ability to extract oxygen from your blood both diminish with age.
Kidneys: Your kidneys shrink and become less efficient.
Lungs: Somewhere around age 20, your lung tissue begins to lose its elasticity, and the muscles of your rib cage shrink progressively. Your maximum breathing capacity diminishes with each decade of life.
Metabolism: You don't process medicines or alcohol as quickly. Your healthcare provider might adjust your prescriptions. Your reflexes are also slowed – so you might want to lengthen the distance between you and the car in front of you and drive more cautiously.
Muscles: Muscle mass declines, especially if you don't exercise.
Skin: Nails grow more slowly. Skin is more dry and wrinkled. It also heals more slowly.
Sexual Health: Women go through menopause. Their vaginal lubrication decreases and sexual tissues atrophy. In men, sperm production decreases and the prostate enlarges. Hormone levels decrease.
Vision: Around age 40, many people have a more difficult time focusing close up. From age 50 on, people are more sensitive to glare, have a harder time seeing in low light, and have difficulty noticing moving objects. By age 70, you might be unable to see fine details.
Whoa, There!
While you can't eliminate aging, you can slow – and in come cases reverse – the process.
Some people are blessed with long-life genes. But based on studies of identical twins (sharing the exact same set of genes), scientists now suspect that lifespan is based on more than genetics. Environmental and lifestyle factors play a role.
Eat healthy foods. Don't smoke. And, of course, exercise. Exercise is one of the best things you can do to live longer and remain self-reliant.
Above all, embrace your years. You might not be able run as far as you could when you were 20 years old, but there are many things you can do better.
Robert Browning penned the now-famous words, "Grow old along with me! The best is yet to be." As we age, we might do well to remember some of the less quoted lines from the same poem ("Rabbi Ben Ezra"):
- …I own the Past profuse
- Of power each side, perfection every turn:
- Eyes, ears took in their dole,
- Brain treasured up the whole;
- Should not the heart beat once "How good to live and learn?"
-
- Youth ended, I shall try
- My gain or loss thereby;
- Leave the fire ashes, what survives is gold:
- And I shall weigh the same,
- Give life its praise or blame:
- Young, all lay in dispute; I shall know, being old.
|
