This issue will continue my series on prevention and will focus on the physical, mental, and emotional changes commonly associated with natural aging. No one knows exactly why we age. There are many theories: genetically set cell death; the accumulation of wastes and toxins inducing cell death or preventing new cells from functioning properly; and decreased blood flow causing decreased supply of nutrients and loss of function. Most likely, it is a combination of genetics, lifestyle, and life experiences.
Physical changes that occur with age include decrease in lean body mass, and muscle fibers and strength and an increase in total body fat. Some of these changes can be linked to reduced physical activity because they are not as pronounced in older people who remain active. Changes in bone mass can cause worsening posture and decreased height.
Cardiovascular changes occur as the heart valves become more fibrous and calcium is deposited in areas of wear. Additionally, the electrical conduction system of the heart can slow or become less coordinated, causing heart rhythm irregularities, extra beats, or overall slowing of heart rate. Breathing changes with age, as older people tend to breathe more from the upper portion, rather than the base, of the lung. This means breaths aren’t as deep and there is less oxygen exchange per breath.
The kidneys decrease in size, with fewer filtering units per kidney and more hardening of the arteries supplying the kidneys. Overall, kidney function decreases with age, which is important for adjusting medications that are cleared by the kidneys. The bladder capacity decreases; many men experience benign prostate enlargement while many women experience vaginal atrophy and loss of vaginal tone. These changes can lead to increased urinary infections and decrease in bladder control.
The stomach and intestines go through both structural and functional changes with age. The esophagus loses motility, increasing the chances of choking or aspiration. There is an increase in gastritis and hiatal hernias, and a decrease in saliva, hydrochloric acid, and pancreatic enzyme production. The decrease in saliva also increases gum recession and cavities; decreases in acid and enzymes will affect digestion and absorption, especially of protein, B12, iron, and calcium.
The skin becomes less resistant to external stressors and loss of sweat and oil glands make the skin more susceptible to trauma, infections, and poor healing. These changes are also why the elderly have more difficulty with extremes of temperature. Blood vessels are more fragile, leading to easier bruising and bleeding. Changes in facial features are also common; eyelids may droop, the jaw may become less prominent, the nose may broaden, and the ears may lengthen.
The senses often change with aging. The lenses in the eye become less elastic and more fibrous, leading to decreased vision as well as cataracts. Glaucoma occurs when the eyes no longer reabsorb intraocular fluid as well, leading to an increase in pressure. The threshold for light perception increases resulting in difficulty seeing in dim light. There is also an increase in the threshold at higher pitches for hearing, and high frequency hearing loss is more common in men. Taste and smell both diminish, but this seems to be related to changes in the brain, rather than the sense organs themselves. It is also important to know that many drugs can diminish a person’s sense of taste.
Sleep patterns change with age, as there are more waking periods during the night, easier waking overall, and less deep sleep. Specific changes in long term memory and cognition are actually not associated with the normal aging process. Most normal elderly patients only show minor loss in recent memory, but mental status can be affected by the physical changes in the brain that are part of normal aging.
The normal changes associated with aging reflect a decrease in the functional reserves of different organs. While these changes may increase risk of some diseases, preventing poor health in our later years starts decades before.