Jerry BrainumAging: What Is Under Our Control?
In 2006 scientists from the School of Ocean Sciences at the University of Wales, Bangor, found an unusual specimen growing on the seabed in the icy waters off the north coast of Iceland. It was an ocean quahog, a clam also known as Arctica islandica. What made that particular mollusk unique was its age: It was between 405 and 410 years old and still very much alive and thriving. Itís now the oldest living creature on earth, eclipsing the old record of 220 years held by another clam found in 1982. The longevity of the newly discovered marine Methuselah makes the human longevity record of 122 seem paltry.
Iíd wager that most people would be happy to live to 100 or more, provided that life span also included a high quality of life. (Living a long time in poor health is hardly ideal.) Most bodybuilders would opt to follow the example of Jack LaLanne, who turns 94 this year. Jack still trains regularly, and I can verify that his grip is as strong as that of a man a half his age. When asked the secret of his high level of health and fitness, the fitness legend cites his continuing workouts and focus on good nutrition. The fact that heís a slight man who hasnít been overweight for most of his life also figures into his longevity.
We cannot entirely halt the aging process, but we can slow it down and maintain our quality of life through the passing years. Contrary to popular opinion, many degenerative diseases associated with aging are not inevitable. Absent genetic anomalies, the two main causes of death, cardiovascular disease and cancer, are largely preventable through exercise and diet.
A recent study involving 2,401 twins proved that exercise slows the aging process at the molecular level. Those who engaged in regular exercise had lower rates of cardiovascular disease, type 2 diabetes, high blood pressure, obesity and osteoporosis. The authors noted that a sedentary lifestyle ďincreases the propensity to aging-related disease and premature death.Ē One portion of the study measured the length of telomeres in participantsí white blood cells. Telomeres are the ends of chromosomes, and their length determines how much more a cell can replicate and repair itself. Shorter telomeres mean faster aging. While all of the subjects in the study had shorter telomeres with age, those who were inactive had considerably shorter telomeres than those who remained active. In fact, the most physically active subjects had telomere lengths that would indicate that they were biologically 10 years younger than their physically inactive counterparts.
Many scientists who study aging differentiate chronological from biological aging. Chronological aging refers to your age in years. Biological aging refers to it from a functional point of view. A 30-year-old can be biologically 50 and a 60-year-old biologically 30. The factors that affect biological age are known as biological markers. In 1991 two scientists from Tufts University published Biomarkers: The 10 Determinants of Aging That You Can Control, whichoffered the then-revolutionary premise that by eating correctly and keeping the body strong through lifting weights, people could extend the quality of life almost indefinitely.
The salient question these days is whether ongoing research on aging confirms the tenets offered 17 years ago in Biomarkers. Letís take a look at those biomarkers:
1) Muscle mass. As most people age, lean muscle is gradually replaced by bodyfat. The loss of muscle may result in a loss of mobility, the primary reason older persons wind up in nursing homes. For a bodybuilder the importance of maintaining muscle increases when you get past age 40. While you may not be able to retain the same mass that you had at 20, the muscle you do retain will improve your quality of life. So the key is to continue training long after your competition days are over. Thatís precisely what most bodybuilding champions do.
2) Strength. A lack of exercise leads not only to muscle loss that accelerates past age 40 but also to a loss of strength. What happens is that the fast-twitch-muscle fibers, which are responsible for both muscle mass and strength, atrophy, or shrink, while the slow-twitch fibers, which are smaller and weaker, become dominant. Studies show that most people who donít exercise lose 20 percent of the fast-twitch fibers in their thighs between 30 and 70. Fast-twitch fibers also dictate speed of movement, and their atrophy accounts for the slowness associated with age. Connective-tissue aging and degenerative diseases, such as arthritis, also play a role.