Happy 200th birthday?

The search for long life is not new. Remember Ponce de Leon? His search for gold led him to Florida in 1545, not the “fountain of youth,” but the legend of restorative waters was well known even then. The legends of Alexander the Great include similar stories dating to the third century.

Today that search continues as the longevity movement. Longevity is the goal of a new medical specialty, anti-aging medicine. The American Academy of Anti-Aging Medicine, or A4M, represents 17,500 members in 86 countries and is still growing.

The movement has a large public following as well, evidence all the workshops, books and magazines about it. The magazine Life Extension recently carried stories like “The Longevity Diet,” “Breaking the Aging Code,” “Baby Boomers Guide to Living Forever” and “Stopping the Clock.”

The movement does have its critics. Some say the emphasis on being “forever young” is unrealistic and ageist. Some point to the marketing of anti-aging aides, such as nutritional supplements, and suggest that selling unproven hope for longer life is unethical and sometimes dangerous.

Dr. Julie Bynum, a fellowship-trained geriatrician at Dartmouth-Hitchcock Medical Center in Lebanon, points to the availability of human growth hormone as an example of a product that comes to the market before being sufficiently tested and understood. Other critics recommend putting money into the lifespan that we have, making it better and healthier.

In fact, the two goals — longer lifespan and improved quality of life — are not mutually exclusive. Current research to understand the process of aging at the molecular level is expected to lead to greater understanding of the diseases that often come with aging.

Much research is aimed at what causes cells to die. Cells are constantly dividing to produce new, replacement cells, but Dr. Leonard Hayflick, a research biologist, has discovered that there is a limit to how many times cells will divide. At some point, each comes to an end. Aging is the gradual process of cell death.

Could the process be changed? Researchers describe strings of DNA called telomeres that bind the ends of chromosomes to keep them from unraveling as cell division takes place. When telomeres weaken, cell division slows, then stops. But there is an enzyme, telomerase, that stimulates telomeres. Could the enzyme perpetuate healthy cell division — on and on? Hayflick thinks not.

Dr. Thomas Perls’ search for the secret of long life took him out of the laboratory to a study of very old people. Perls is a geriatrician at Beth Israel Deaconess Medical Center and director of the New England Centenarian Study. He is the author, with Margery H. Silver, of “Living To 100,” the first comprehensive North American study of the oldest people in the world, all age 100 or over.

Perls found more variety than he expected. Some had Spartan diets, others did not. Some were highly educated, some were not. Several had never married, some had many descendants. He also found commonalities. All ate in moderation. None used tobacco. Most had always been healthy. Many of the women had given birth in their 40s.

Perls, intrigued to find that many of the centenarians had siblings in their late 90s, began a study of siblings and extended families. The familial pattern of long life was clear. In the “R” family he studied, there were 21 first cousins over the age of 90.

The team concluded that the primary factor in longevity is genetic inheritance. Some people age more slowly and are more resistant to disease than others. (The older you are, the healthier you’ve been.) This does not mean that genetics is the only factor. Personal choices can be health enhancing or not. Also, adds Perls, there were undoubtedly many people in the past century with the genes for longevity who did not live to their potential because of public health problems such as infectious disease and unsafe water supplies. They passed on the genes for longevity to their now-aged offspring.

Perls also participated in a clinical study at Beth Israel Deaconess, the first to use humans to try to find the genes that play a role in lifespan. The study identified a region on chromosome 4 that likely contains one or more genes associated with exceptional long life. There could be from 100 to 400 genes involved, however, so we are a long way from knowing which gene or group of genes that might be.

Has anti-aging medicine come into the mainstream? Dr. Samuel Goldman, a geriatrician at Elliot Senior Health Center in Manchester, believes that the anti-aging movement provides valuable insight to individuals and to the medical community. The center brings together medical care, psychiatry, social services, physical therapy and educational opportunity into one integrated program for older adults.

“People become aware of personal responsibility for health,” he says. “The [Anti-Aging] Academy brings a positive approach and excitement to the field of aging.” And he believes that cell research will lead to cures for diseases of late life such as Parkinson’s. He shares Dr. Bynum’s concern that information is sometimes widely disseminated before long-term studies have supported initial findings. He points to the now-discredited claims about vitamin E.

His typical patient is in her 80s, and many are older. Even so, he encourages patients to help themselves, to take personal responsibility to remain healthy. But many need support. He believes that there is a community responsibility to provide the support that older people need. As exciting as anti-aging medicine is, today’s elders must deal with problems of income, isolation, housing and health care. “My older patients are not so interested in extending the lifespan,” he says. “They value the lives they have lived and are not much concerned about death.”

In Dr. Bynum’s practice at Dartmouth-Hitchcock Medical Center, over 80 is the norm. She is fellowship-trained in longevity studies and follows new developments in the science of aging. The science is exciting, even thrilling, she says, but the practice is “not there yet.”

As the search for long life continues, the populations of Western nations are growing older. Demographer James Vaupel of the Planck Institute says that since 1990 the number of centenarians has grown by 4.1 percent a year and that, by 2029, living to 100 will be the norm. Others in the longevity movement say people can live to 150, even 200. A sure sign of the trend — Hallmark Cards now sells a line of birthday cards for the centenarian in your life. NH