Each year an increasing number of people beat the mortality odds and live to celebrate their first century. In fact, the 100+ club is the fastest growing segment of the US population. The US Census Bureau estimates there are 60,000 men and women over the age of 100 living in America today.
What special hand did they play to insure their longevity? Was it diet, exercise, happiness, or simply a lucky role of the genetic dice that kept them from succumbing to heart disease, cancer, or diabetes? These are the questions gerontologists hope to discover by studying the life-long habits of centenarians like Edna Washington.
Currently, we are ten years into the Georgia Centenarian Study at the University of Georgia in Athens. The study has been investigating the characteristics of our oldest old and how longevous parents, support systems, friends, religion, family, education, and intelligence contribute to longevity.
"Aging defies easy definition," says Leonard Hayflick, Ph.D., researcher at the University of California, San Francisco School of Medicine and author of How and Why We Age (Ballantine Books, 1996). "Aging is not merely the passage of time. It is the manifestation of biological events that occur over a span of time." We've all known people who have looked "half their age" or aged "more than their years"-demonstrating the variance between chronological and biological aging.
Scientists estimate the maximum life-span of humans to be about 115 years. To date, no one with reliable birth records has surpassed this watermark for human life. Despite the complexity of the aging process and the variety of changes that take place in the body as we age, there are many factors that we can be reasonably sure contribute to our march toward mortality.
Cell Aging and Death
Thirty years ago, Dr. Hayflick discovered that normal human cells, grown in a lab, divide about 70 times and die; suggesting that aging and death is programmed into the very building blocks we are made of. But how does this process work? What changes are taking place in the cell?
Telomeres, a cellular clock located at the ends of our chromosomes, seem to be largely responsible for this change. The telomere is made up of extra non-essential amino acids. Each time the cell divides a bit of the telomere is lost, growing ever shorter at a fixed rate with each division.
Still, our cell's maximum of 70 divisions is more than adequate for a human living to 115. It appears, as the extra ends shorten, cells gradually lose function and eventually die before completely using up their telomeres.
Interestingly enough, some cancer cells are immortal. They have a gene that produces an enzyme called telomerase that adds more telomere after each division so growth can continue indefinitely. Researchers at the University of Texas Southwestern Medical Center at Dallas recently discovered a way to transfer this gene into normal cells, enabling them to produce telomerase and become immortal normal cells.
Future drug applications of this discovery may help treat age-related disorders such as wrinkles, some forms of blindness, and heart disease. However, it is still unknown whether aging at the cellular level is directly responsible for the aging of a total living organism.
Caloric Restriction
The population with the current longest documented lifespan are the Okinawan Japanese. These islanders can expect to live, on average, to 84 years. (Current US life expectancy is 75.) They consume a diet of only 2,800 calories per day, rich in soy and low in saturated fats.
Since the 1930s researchers have observed a one-third increase in lifespan in laboratory animals fed a reduced calorie, nutritionally adequate diet. For us that would be like living to 150. Cancer, and heart and kidney disease in these animals is reduced-in fact, calorie restriction is the only known proven single method for increasing life expectancy.
Reducing calories slows metabolism, reduces body temperature, and may just simply retard development processes, including aging. Short-term studies on humans have found these diets to lower blood pressure, cholesterol, and blood sugar levels. However, no studies have followed reduced calorie diets in humans throughout their lifespan for obvious reasons.
A centenarian dietary study of seventy people ages 100 to 108 in Italy, observed that the men ate 1,600 calories per day on average, women 1,400; with a diet make-up of 60 percent carbohydrate, 19 percent protein, and 21 percent fat.
Stress
Some studies show type A (stressed-out, easily excitable, or angry) personalities are more likely to die of a heart attack. Stress weakens immunity, and effects hormone and cholesterol levels. However, some stress is good for you. Excitement and personal challenges are healthy, keeping the mind and body alert. Many centenarians remain active in their community, church, or family, and have a variety of interests and hobbies.
Social Activities
Studies across the board show people who enjoy close loving relationships with friends, family, or spouses live longer than lonely people. Satisfying relationships are credited with reduced likelihood for alcohol abuse, poor eating habits, or sedentary patterns. Pets work just as well, for reducing blood pressure, heart rate, and stress. Dogs are rated as having the most longevous effects on their owners.
Sex
Regular sexual activity is healthy for people of all ages. It has been revealed that people who reach very old age in reasonable health engage in sexual activity on a regular basis. Sex releases endorphins, reduces stress, and strengthens the immune system. Wild tales of fatal heart attacks during sex are largely fictional.
Hormones
Hormones are the key chemical messengers that regulate most of our body functions. After age 30 our hormone levels begin to decline. Researchers have been examining falling hormone levels as possible triggers for aging. Two, in particular, have received a good deal of media attention lately: melatonin and DHEA.
Melatonin is excreted from the pineal gland and regulates our daily rhythms, including sleep and wakefulness. It is one of the most powerful antioxidant hormones we produce. Melatonin levels decline with age, giving us less protection against free radical diseases such as cancer. Melatonin does increase lifespan by 20 percent in some animal studies, however such experiments have yet to be conducted on humans for increased longevity.
Dehydroepiandrosterone (DHEA) is also associated with longer life and decreased death from chronic disease. An adrenal hormone, DHEA decline has been theorized as a marker for aging. Studies are now just barely underway, yet DHEA nutritional supplements are already fast sellers, along with melatonin, in the natural foods market. Safe and effective dosage of DHEA has yet to be determined and may cause an increase in endometrial cancer in women and prostate cancer in men. However, as research advances, these two hormones may become big players in the fight against aging.
Vegetarianism
Vegetarians are less likely to die of cancer and heart disease and have less incidence of adult-onset diabetes, gallstones, kidney stones, and osteoporosis. In a German study, vegetarian immune system cells were twice as efficient in battling cancer cells than those from meat eaters.
Seventh-Day Adventists are a conservative Christian group that prohibits the use of alcohol, tobacco, and pork, and strongly recommends members follow a vegetarian diet. Studies of this population have been significant in determining dietary and lifestyle causes of disease and longevity in the absence of data-distorting tobacco and alcohol health influences.
The Adventist Mortality Study from 1958 to 1985 recorded the diet and exercise habits and causes of death of 25,000 Adventist men and women living in California. This first study found that Adventist women live 5 to 8 years longer, and Adventist men 2 to 5 years longer than the general population. Abstinence from smoking and drinking is credited largely with this difference as well as an increased diet of fruits and vegetables and a decreased consumption of meat.
"A relatively thin Adventist who emphasizes fruits and vegetables and exercises moderately may reasonably expect an extra 10 to 12 years of life as compared to a relatively obese, non-exercising, high fat/meat consuming Adventist," sums up Loma Linda University Adventist Health Study Director, Gary Fraser, M.D., Ph.D.
Antioxidants and Anti-Aging Nutrients
One of the most popular theories of aging is based on the threat of cellular damage from an onslaught of oxygenated free radicals. Free radicals are aggressive molecules that attack our cells, robbing electrons, resulting in cell and tissue damage and an increased risk of developing cancer and hardened arteries. Fortunately, we can shield ourselves from this attack by ingesting higher levels of antioxidants that give up their electrons more readily than our own cells.
The American Institute for Cancer Research announced last year that eating more fruits and vegetables and getting more exercise results in a 30 to 40 percent decrease in cancer risk.
Getting enough of the right vitamins and minerals also results in better immune function. One theory of aging is that we age and die as a result of declining immune function, making us more and more susceptible to diseases easily fended off in our youth. With age, our immune system produces fewer antibodies and is increasingly more likely to make mistakes and attack normal body proteins-leading to auto-immune diseases such as lupus and some forms of arthritis.
Supplementing your diet with a healthy dose of antioxidant supplements is becoming a more popular recommendation among physicians. As we age, our stomach acid weakens and absorption of nutrients decreases. Antioxidant, immune-boosting, and anti-aging vitamins and minerals to add to your diet include:
Vitamins A, C, & E-are your most effective daily antioxidant formula, best when taken in combination for battling free radicals. In addition, C boosts immunity, and E protects against heart disease.
B vitamins- are essential for brain and nerve function. Many aged folks with memory impairment are deficient in certain B vitamins, especially B12.
Calcium-To prevent osteoporosis in later life, maximize bone building when young. Women need 1,000 to 1,500 mg daily. Calcium lowers blood pressure and cholesterol and inhibits cancer. Vitamin D helps the body absorb calcium.
Chromium-controls insulin and blood sugar levels and raises good cholesterol. Chromium is missing in refined foods.
Magnesium-Antioxidant magnesium helps keep the heart functioning smoothly. Arrhythmias are often caused by inadequate magnesium. Magnesium regulates heart beat and blood pressure, and helps prevent blood clots.
Selenium-has anti-cancer effects, prevents mutations, repairs damage, and boosts immune function.
Zinc-Our thymus shrinks as we age, resulting in decreased immunity. Zinc immune function.
Coenzyme Q-10-helps protect arteries, revives failing hearts, lowers blood pressure, and boosts immunity.
Exercise
"Exercise has little influence on life expectation. If it did, we would find lumberjacks, stevedores, and baseball players outliving cab drivers, businessmen, and general loafers," says Dr. Hayflick.
It's true-exercise won't increase your lifespan in the absence of disease. However, most of us succumb to the degeneration of chronic disease long before we reach our upper age limit. In this case, exercise does effect longevity, in the form of reduced risk of heart disease, angina, adult-onset diabetes, osteoporosis, and hypertension. Exercise may even raise good HDL cholesterol and lower bad LDL cholesterol.
Although we lose muscle fibers and heart pump capacity with age, it's never too late to begin building fitness. According to scientists at the National Institute on Aging, even people age 60 and older can improve their cardiovascular functioning by participating in a regular aerobic exercise program.
Hulda Crooks, a mountain climbing Seventh-Day Adventist grandmother began scaling 14,000 ft. mountains in 1950 at the age of 54. She took up jogging at 72, and at 82 set a world record in the Senior Olympics.
"Good health is a way of life," said Crooks adding that exercise; a vegetarian diet; and faith in God, love, and kindness is what helped her to live to the ripe old age of 101.
Dietary and Lifestyle Pitfalls
What you eat is just as important as what you don't eat when it comes to outliving diet-related diseases that catch most of us before age 75. Here's a list of foods and habits to avoid as much as possible:
- Smoking
- Excessive alcohol consumption
- Sedentary lifestyle
- Obesity-over 30 percent body weight in fat
- Excessive sodium & caffeine intake
- Too much sugar & simple carbohydrates
- Eating "bad" fats, especially rancid, free-radical ridden, oxidized fats.
- Avoid safflower, corn oil, and trans fats (hydrogenated "solid" oils, shortenings, margarines). Use olive oil instead
- Eating meats (filled with cholesterol, fat, and free radicals)
- Overeating, eating too many calories
- Consuming too much iron
To 100 and Beyond
Our oldest old are not only living longer, but better. According to researchers at Duke University, 1.2 million fewer elderly were disabled in 1994 than predicted, based on disability rates from 1982. Better nutrition, education, reduction in tobacco use, economic status, and medical advances are credited for this decline.
Now that we have well-founded theories on the biology of aging and physical decline, and we know much about the root nutritional and hormonal causes of chronic diseases-we can slow down the clock, rebuild some of what time has crumbled away, and live a longer healthier life with fewer diseases well into our 90s and 100s.
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