How to Live to Be 120 (cont.)

Not Your Average White-Coated Lab Rat

To be sure, Walford, 76, is unconventional. He sports a shaved head and a walrus moustache, and he lives a rather bohemian existence in a boarded-up commercial building just steps away from the Venice boardwalk -- a place where people come to whirl on skateboards, get tattooed, and sometimes espouse kooky theories. He has published fiction and poetry, dabbled in performance art, and among other expeditions, has trekked across Africa.

Yet Walford has also maintained a distinguished career as a gerontologist for more than 50 years. An adventurer as well as a scientist, he is best known for his two-year stint in Biosphere 2, the utopian greenhouse experiment in self-sustenance conducted in Oracle, Ariz. Because many of its crops failed, the Biosphere inadvertently became a human study in severe calorie restriction -- in fact, the only such study that has been done on humans to date.

But Biosphere also took a serious physical toll on Walford. Working six days a week in the fields left him with an injured back that ultimately required surgery. Worse, he suffered nitrous oxide poisoning because the structure's glass enclosure prevented ultraviolet light from penetrating and dissipating the gas, an agricultural byproduct. The resulting nerve damage has made it difficult for Walford to walk. When we meet, he sits somewhat hunched behind his desk the entire time. He appears more frail and diminutive than I expected.

The Science of Calorie Restriction

The notion that humans may live 50% longer if they eat less is extrapolated from work with animals, Walford says. The first research showing that calorie-restricted rats live longer than their regularly fed counterparts was done in 1935 at Cornell University. Subsequent studies over the last 65 years (Walford estimates that there are 2,000 to 3,000 papers on the topic) have produced similar results and have also indicated that animals on calorie-restricted diets have a lower incidence of cancer, arteriosclerosis, and autoimmune disease. Results have been so promising that the National Institute on Aging (NIA) now spends $3 million a year to study caloric restriction, mostly in rats and monkeys, and has funded Walford's work in the past.

Walford has been doing pioneering calorie restriction work with animals since the 1960s. He's found that the animals not only live longer, they live better. For instance, his 1987 study in the Journal of Gerontology found that when mice of varying ages were placed on rotating rods to test their muscle strength and coordination, calorie-restricted 31- to 35-month-old mice performed just as well as their 11- to 15-month-old counterparts. Likewise, the older mice did as well on maze tests, indicating that they had no apparent decline in mental function. "People say they don't want to live to 120 because they think they're going to be frail for 40 years," says Walford. "They don't realize that calorie restriction extends the period of viability and good health."