Are there any shortcuts to a long life?

Well, some people like Meredith Averill, 61, and her husband, Paul McGlothin, 60, believe they may have the answers and they're putting themselves to the test in their quest for longevity.

The couple have been practicing calorie restriction for the last 14 years. Calorie restriction is the only proven way to extend life in animals and, now, studies are getting started in humans.

Averill and McGlothin are the subjects of one such study. As calorie restrictors they eat only specific amounts of foods that are high in nutrition but low in calories -- foods like vegetables, fruits and beans.

At almost every meal, they weigh their food and keep detailed records in their laptop of the nutrition and calories they are consuming. Averill eats about 1,500 calories and McGlothin about 1,900 -- that's about 30 percent less than what the average American eats.

"In almost every animal species, it has increased life significantly," said Robert N.Butler, a gerontologist and president of the International Center for Longevity. "If you reduce by about 30 percent, you get 30 additional percent of life."

Averill and McGlothin claim the benefits of calorie restriction are astounding. They share their healthy diet and lifestyle tips as co-authors of a new book, "The CR Way " (Harper Collins).

"My heart and blood vessels are like a person many decades younger," Averill said.

McGlothin said, "Doing calorie restriction, in the way that we do, is like night and day in terms of being able to function. I'm 60 years old. I have 20/20 vision. On IQ tests I've improved 30 percent over the last 14 years, it's usually just the opposite."

Some people are taking a different approach in their search for longevity.

Dr. Terry Grossman runs the Grossman Wellness Center in Denver. He says you need a long-term systematic plan that includes strength training, a healthy diet and meditation. With an emphasis on prevention, he starts with a comprehensive medical exam lasting two full days.

"We run a battery of tests over a few days and we'll find that people have certain genetic predispositions to diseases or they have certain conditions or family history of diseases," Grossman said. "So we'll use some supplements or medications that are specifically designed to prevent or treat those [ailments]."

Ray Kurzweil, a 60-year-old scientist and award-winning inventor, teamed up with Grossman to write a book on the future of aging called "The Fantastic Voyage." They believe that in addition to a healthy lifestyle, a personalized plan of aggressive supplementation helps to slow the aging process.

Kurzweil, winner of the National Medal of Technology and other prestigious science awards, said, "I'm taking, you know, 150 different substances, each of which has a lot of scientific evidence behind it. I have the hormonal levels and the nutrient levels of a 40-year-old. If I wasn't doing this, that would not be the case. And I confirm this with blood tests every few months, based on how I feel and my productivity and -- so I'm not flying without an instrument panel."

So what is exactly he is taking? Some are familiar, such as basic vitamins and minerals, and not so familiar such as phosphatidylcholine. Kurzweil says that phosphatidylcholine actually reverses the aging of the cell membrane.

But other experts such as professor Jay Olshanksy of the Chicago School of Public Health thinks most supplements are a waste of time and money. He notes that for the vast majority of the people who are taking nutritional supplements," all they have is very, very expensive urine, and that's it."

Most experts, however, seem to agree that everyone should exercise, eat less and lower their stress levels. And, as for the value of caloric restriction and supplementation to extend life, it will be years before we know for sure.

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