Science Behind Living Longer 

This family could teach all of us about living life to its fullest.

"The Hurlburt family is positive and happy and get along fine together," 81-year-old Peter Hurlburt said.

Eleven siblings -- four feelin' fine in their 90s. The rest? Energetic in their 80s. All share several common denominators.

"We all feel good," said 93-year-old sibling Millie Hurlburt MacIsaac. "None of us are in wheelchairs or walkers or canes."

"Don't drink, don't smoke, don't worry," 96-year-old Agnes Hurlburt Buckley added.

Now they're all looking forward to reaching the 100-year mark.

"I never thought i would live this long," Millie said.

But why this family? Some say they won the genetic lottery.

"I think mostly because we've got good genes," said Peter.

Experts say this is the new 30-70 rule: Thirty percent of aging is genetically based. The other 70 percent is in our hands. Right now, biologists and geneticists are pursing the secret to longevity on a cellular and molecular level.

"We can't control our genes," MIT biologist Lenny Guarente, Ph.D., said. "Our genes are what they are, but what we can do potentially is design drugs and health supplements that might alleviate some of the deficits of having a bad gene here or a bad gene there."

Dr. Guarente believes the key could be in something called sirtuins.

"Sirtuins are a family of genes that we discovered in yeast that can make the cells live longer."

It turns out, we all have them.

"We believe by keeping these genes functioning properly, we can forestall aging. It can slow down aging," Dr. Guarente said.

Scientists found one way to activate these anti-aging genes -- resveratrol, which is found in grapes and red wine and already marketed as a wonder drug to the masses.

Another promising anti-aging compound -- the cancer drug rapamycin. It extended life in mice, but scientists say it's not ready for use in healthy people.

"They're potentially poisoning themselves," Lewis Lipsitz, M.D., director of the Institute for Aging Research at Hebrew SeniorLife in Boston, Mass., told Ivanhoe. "So there are dangers in actually taking something like this, which is not intended at all as an elixir of life. It's intended as a chemotherapeutic unit."

Tom Perls, director of the New England Centenarian Study, is fighting aging in another rather surprising way.

"I menstruate once every 8 weeks, and the way that I do that is to donate a unit of blood," Dr. Perls told Ivanhoe.

He believes a woman's menstrual cycle is one reason women delay the onset of age-related diseases like heart disease or stroke by 10 years.

"They're relatively iron deficient for about 30, 40 years compared to men, and it may be as simple as less iron in your system," Dr. Perls explained.

While some believe less iron is key, others believe fewer calories can add more healthy years to your life.

"Eating less: Of course, no one wants to follow that advice," said Dr. Lipsitz. "They'd rather find a medication."

"The wrong food can create havoc, and it usually does," Anthony Bazzan, M.D., co-director of the Great Life Program at the Jefferson-Myrna Brind Center of Integrative Medicine in Philadelphia, Penn., told Ivanhoe. "The right food can change the body for the better in a way that cannot be done with drugs or supplements."

Whatever it is, it's a race against time to find the answer.

"The formula for one person to get to a very old age can be very, very different for another," Dr. Perls said.

The Census Bureau forecasts the 65 and over population will increase from 38 to 88 million by 2050, making the Hurlburt family not one of the few -- but one of the many defying father time.

One drug may not be the answer to a long life, but one superpill may be. Right now, drug companies are working on combining ace inhibitors to clean up blood vessels, statins to lower cholesterol and aspirin to prevent heart attacks into one pill to help prolong life.

Research Summary

ABOUT SIRTUINS: Sirtuins are a family of genes that scientists discovered in yeast that can make cells live longer. Their significance? "We believe that keeping these genes functioning properly can forestall aging -- it can slow down aging," Lenny Guarente, a biologist at Massachusetts Institute of Technolgoy in Boston, Mass., told Ivanhoe. "The trick will be figuring out exactly how to do that." Sirtuins -- which turn out to be present in all living organisms -- can detect energy reserves in a cell and are activated when those reserves are low, such as when someone eats a calorie-restricted diet. Scientists argue that drugs to activate sirtuins could offer the same lifespan extending benefits as a calorie-restricted diet.

RESVERATROL: WONDER-DRUG OR HYPE? One chemical that has been shown to activate sirtuins is resveratrol, which is a compound naturally found in grapes, red wine, peanuts and some berries. The compound sparked interest in the supplement industry and is already marketed over the counter as a dietary supplement. A drug formulation of resveratrol is in clinical trials as a treatment for type 2 diabetes and cancers. While it has shown promise in animals, long-term studies have not yet been conducted in humans using resveratrol, and some experts caution that dosages of the supplement vary widely. "The problem with taking the supplement instead of the berries is you have no idea how much resveratrol you're getting in the pill," Susan Hewlings, Ph.D., R.D., assistant professor of medicine at the UCF College of Medicine in Orlando, Fla., told Ivanhoe. "You can get the same benefit -- which are antioxidant properties and heart protective properties -- by consuming berries and the dark red grapes."

LESS CALORIES, LONGER LIFE? Decades of animal studies have shown that semi-starvation can extend lifespan by up to 50 percent. Last July, researchers at the University of Wisconsin found calorie restriction extended the lives of rhesus monkeys by reducing the incidence of diabetes, heart disease and cancer. Scientists suggest that in order to add to longevity, a calorie-restricted diet should be defined as one with 25 to 30 percent fewer calories but still containing essential nutrients.

A nationwide, multi-center study is underway to determine of such a diet can extend human lifespan. Called the Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy (CALERIE) study, participants will be on a restricted calorie diet for two years. Their diet restriction of 25 percent is based on their resting metabolic rate, or the number of calories each person burns in one day. So far, most participants reduced their body mass by about 15 percent in the first year.

From The Denver Channel - ABC 7