A Power Program for Student Review
Course Coverage 2016
- Jan Fit To Last
- Feb Urbanized Eating
- Mar Mind & Memory
- April Special Senses
- May Metabolic Syndromes
- June Sugar Diabetes
- July Diabetes Complications
- Aug Aging
- Sept Atheroma
- Oct Longevity
- Nov Cancer
- Dec Predicaments
Last month’s topic Aging, is summarized in this Countdown… Only a few decades ago, people regarded aging as a life-stage, a point of passage on a voyage with inevitable symptoms and signs: the trail-wear of a trip taken, a life fully lived. But most individuals entering their middle years these days feel no older, preferring to act younger and not look any older, either. Skin wrinkling and sagging are their most common medical issues of concern, the result of lost tissue elasticity. Less visibly, the same process also wrinkles organs like the liver and kidneys.
Aging, while recognized from its symptoms and signs, just like a disease, it is not a disease. There’s graying and forgetting; wrinkling and sagging; slowing and fumbling; stumbling and falling; shrinking and stooping; and frailty with failure…but it’s not a disease. Aging delayers can be promoted…aging accelerants can be avoided…and its disease disruptions can be defeated
Further evidence of aging is slowing, and best seen in the speed of nerve impulse transmission. Slower reaction times accompany memory failure. Nerves are like electric wires. They must be insulated from each other with a wrapping called myelin, that begins to thin away mid-life, starting in the frontal region of the brain to reveal itself an short-term memory loss. Many patients incorrectly assume such changes to be gene-based and beyond improvement, but new research suggests otherwise. The brain is a living organ, not unlike muscle. Its functions are best preserved by making daily demands on it. As for muscle, use or lose brain power remains the rule.
Brains are composed of tissue that is inclined to waste away if underused. Brain size declines with age more from neglect and underemployment than from the wearing away of overuse. The most scientific way to delay brain aging (from the negligible physical demands of modern life) is with daily exercise. Repeated testing shows that stimulation preserves nerve mass and transmission speeds. Studies of men in their 60s and 70s, actively fit for a decade, confirm nerve reaction times faster than sedentary male controls half their age.
The chemistry of life is called metabolism and involves the use of oxygen for energy to grow and function. Metabolic waste must be removed and cell machinery repaired. A byproduct of oxygen use is the production of irritants, called free radicals, released continually into a cell’s watery environment. Like smoke from industrial chimneys, free radicals wear away cell membranes and reduce elasticity throughout the body. Holes develop that leak cell juices, causing tissues and their contents to shrink, for still another sign of aging. The basic life unit is the cell with its chromosomes and machinery and juice. Each cell has a short, purposeful existence lasting weeks or months embedded in its tissue organ system to be replaced from a tissue pool of stem cells that are not immortal either. Only cancer cells are immortal…for later coverage…because avoiding cancer aids longevity.
Cell membranes are protected from the harmful effects of free radicals by antioxidants that are quite abundant in foods of plant products. From digested fruits and vegetables anti-oxidants drift around in cell juices like security guards, ready to collar free radicals before they can trash the cell’s neighborhood. Antioxidants in fruits and vegetables are well-recognized to protect against longevity shorteners like cancer, heart attacks and strokes.
Along with the aging hazards of free radicals, high blood sugars can also contribute to aging. When levels are high, glucose molecules couple with proteins in body tissues in a process called glycation. It compromises tissue function by producing less flexibility and greater rigidity, two more signs of aging (like lost elasticity) so patients with diabetes tend to show signs of aging prematurely.
Menopause is a most conspicuous reminder of female aging…signaling the end of a woman’s reproductive life, and a new time of lower estrogen levels throughout her body. Menopause is triggered by age-related changes in the central nervous system, in pacemakers that are housed deep in Old Brain. Menopause results from a shutdown of the brain’s neuroendocrine clock, not, as once thought, an egg exhaustion in the ovaries. Low estrogen levels prompt an aging affect on all reproductive tissues, on bone and mineral metabolism, on memory and cognition.
Although less dramatic in males, their neuroendocrine clocks also begin shutting down in the late middle years with a gradual reduction in circulating testosterone and comparably diminished brain maintenance of mood, memory and cognition.
A recent Cleveland study of more than 100 autopsies on elderly men and women is most insightful. All patients studied had died in comfortable old age…enjoying the ‘ideal’ retirement of supportive surroundings, community meals, occasional cards, evenings of music or television. None had been active, and none were considered disabled. Nothing in their autopsies revealed why each had died at the moment he or she did die. Each had lived for months or years before death in comparable peaceful inactivity. Each appeared to have died through a simple withdrawal from life. So the purported benefits of daily walks or dancing or…(gasp!)…jogging are real and up for grabs…to any codger seeking them.
Aging also compromises immune system effectiveness through a gradual replacement of youthful, vigorous defensive cells by older defensive cells hobbled by structural defects and functional impairment. This increases an older individual’s vulnerability to infection because aging immune systems become populated by a declining body of strong immune veterans. They are legacy cells that well remember past exposures and jump to the rescue. The aged immune system responds slowly and less protectively to new infections.
Aging is a trip we have all embarked upon with an average human duration of 100 years, the human life span with a normal distribution curve spread of 80 to 120 years. Luck, of course, plays a part where each of us falls on the curve, but the trip’s navigation skills are ever more important.
The latest researches to have delved deepest into the causes of aging…deeper than oxidation, glycation or cellular clutter…to examine stem cells. Every tissue has a small pool of them, and throughout life they generate replacements for each working cell that has become damaged or worn out. The stem cell pool itself has been found to age through cell replacement rates slowing down and stopping. The number of stem cell replications limiting each creature’s life span are determined by the length of a chromosome monitoring device called a telomere. It is a delicate brush-like tuft at the tip of each chromosome that shortens with every replication, and thus determines our life span…from 80 to 120 years.
Age has become the common denominator of most fatal diseases in the developed world. It is associated with heart attacks, strokes, cancer and the dementias. A better understanding of the biology of aging can help you promote a healthier longevity – your health span – which would compress any inevitable terminal morbidity into a briefer time period. This is the object of Geroscience, a new bio-research specialty devoted to the promotion of healthy aging.BLAST OFF