“How old would you be if you didn’t know how old you were?” ~ Leroy “Satchel” Paige
Today’s post is the first of a series on “How to Prevent Aging”. By having an understanding of the physiological changes, the causes, and effects on the rate of aging, you can adjust the way you live, work, and play and prevent or delay the onset of diseases that are disproportionately associated with aging.
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Chronic diseases and disability were once synonymous with old age, but after over fifty years of research by the U.S. National Institutes of Health (NIH), you can prevent or at least control certain diseases, often through the way you live.
Individuals age overall at immensely different rates, and age-related changes in cells, organs, and tissues differ greatly as well. Organs in one individual may age faster than those in another. For example, your bone strength may diminish more rapidly as compared to your spouse whose heart function may decline faster. This suggests that the rate of aging is affected by:
“Normal aging” varies considerably and its rate can be affected by behavioral factors in your control, such as healthy eating and physical activity. Age in years does not necessarily correlate with physiological age.
Views on aging are changing and chronic disease isn’t necessarily an intrinsic part of the aging process anymore. Today, people are living longer and there has been a dramatic decrease in the rate of disability among older people in the last twenty years. The average life expectancy at birth was:
- 63.6 years in 1940
- 68.1 years in 1950
- 70.8 years in 1970
- 76.9 years in 2000 (9.3 million aged ≥80 years)
- 77.7 years in 2006
- 78.1 years in 2009
Source: U.S. Census Bureau, International Database and National Vital Statistics System
By 2030, it is estimated that individuals aged ≥80 years could grow to 19.5 million and the “oldest-old” (aged ≥85 years) could grow to 10 million people.
The following is a brief overview of what happens to some of your body systems as you age:
- Heart muscle thickens.
- Maximum pumping rate diminishes.
- Body’s ability to extract oxygen from the blood diminishes.
- Maximal oxygen consumption during exercise declines 7.5-10% with each decade of life.
- Arterial walls stiffen. Arteries transport oxygenated blood away from heart. In order to propel blood through the stiff, less elastic arteries, the heart must exert more force.
- Capillary walls become more fragile and prone to rupture, and tissues supporting these vessels weaken. Capillaries are tiny, extremely narrow blood vessels.
- Vital capacity of the lungs decreases by about 40% between the ages of 20 and 70. Vital capacity is the maximum amount of air you can expel from your lungs after first filling them up to their maximum capacity and then expiring to their maximum extent.
- Connections between nerve cells (neurons) decrease.
- Individual nerve cell function diminishes.
According to recent studies, the adult nervous system is capable of producing new neurons, but the exact conditions for this to take place has yet to be determined.
- Efficiency at removing waste from the blood diminishes.
- Total bladder capacity declines.
- Tissues atrophy which may cause incontinence (particularly in women).
- Percentage of body fat increases until middle age, stabilizes until late life, then body weight typically declines.
- Both muscle and fat decrease as body weight in older individuals declines.
- Cushion of fat redistributes from just beneath the skin to deeper organs.
- Between ages 30 to 70, muscle mass declines without exercise – a 22% decrease in mass for women and 23% for men.
- Bone density diminishes. Although bone mineral loss is continually replaced, at around age 35, replacement cannot keep up with the loss.
- Bone loss accelerates in menopause.
- Age ≥40: Focusing on objects that are close becomes difficult.
- Age ≥50: Susceptibility to glare increases and ability to see in low light becomes increasingly difficult.
- Age ≥70: Ability to distinguish fine details diminishes.
- Hearing higher frequencies becomes difficult.
- Understanding speech becomes difficult, especially where there is background noise – even with good hearing thresholds*.
*Rate of hearing loss is greater in men than in women.
- Ability of the lymphocytes, specifically T-cells, to renew and function efficiently diminishes. T-cells attack cells that have been infected or damaged and also produce chemicals (lymphokines) which direct the immune system response.
Thymus (where T-cells develop) shrinks in size.
Source: “Aging Under the Mcroscope – A Biological Quest”, National Institutes of Health/National Institute of Aging
Fit Tip: You have considerable control over preventing, slowing, and adapting to the physiological aging process. That is, you can take steps to live both longer and stronger. As this series continues, visit the How To’s, Ask Karen, and Recipes sections of this website and read up on news and tips that promote living well to lengthen your active life.
Coming Up Next: How to Prevent Aging: Part 2 (Skin Changes)
© 2009 Karen Owoc and The Health Reporter™. All Rights Reserved.