Scientists have long tried to find ways and means to slow down aging. Recent research has revealed that calorie restriction may be the answer to extend life.
At the Wisconsin National Primate Research Center laboratory, rhesus monkey Matthias at 28 is losing his hair, lugging a paunch and getting a face full of wrinkles.
However in the cage next to his, gleefully hooting at strangers, one of Matthias's lab mates, Rudy, although a little older is the picture of monkey vitality. He is thin and feisty, pirouetting toward a proffered piece of fruit.
Rudy and primates like him owe their vigor to certain simple lifestyle modifications called calorie restriction, which involves eating about 30 percent fewer calories than normal while still getting adequate amounts of vitamins, minerals and other nutrients.
So far aside from direct genetic manipulation, calorie restriction is the only strategy known to extend life consistently in a variety of animal species.
Over the last year, scientists have found that calorie-restricted diets have been shown in various animals to affect molecular pathways that are involved in the progression of Alzheimer's disease, diabetes, heart disease, Parkinson's disease and cancer.
Researchers studying dietary effects on humans have even claimed that calorie restriction may be more effective than exercise at preventing age-related diseases.
These findings have cast doubt on long-held scientific and cultural beliefs regarding the inevitability of the body's decline as well suggesting that other interventions, which include new drugs, may retard aging even if the diet itself should prove ineffective in humans.
In this endeavor a newly synthesized form of resveratrol an antioxidant present in large amounts in red wine is already being tested in patients. It may eventually be the first of a new class of anti-aging drugs. Extrapolating from recent animal findings, Dr. Richard A. Miller, a pathologist at the University of Michigan, estimated that a pill mimicking the effects of calorie restriction might increase human life span to about 112 healthy years, with the occasional senior living until 140, though some experts view that projection as overly optimistic.
Such a drug has been estimated to be among the most cost-effective breakthroughs possible in medicine, providing Americans more healthy years at less expense (an estimated $8,800 a year) than new cancer vaccines or stroke treatments.
"The effects are global, so calorie restriction has the potential to help us identify anti-aging mechanisms throughout the body," said Richard Weindruch, a gerontologist at the University of Wisconsin who directs research on the monkeys.
Many scientists regard the study of life extension as a national priority. Government census data has shown that the number of Americans 65 and older will double in the next 25 years to about 72 million by which time seniors will account for nearly 20 percent of the population, up from just 12 percent in 2003.
Four prominent gerontologists, among them Dr. Miller, published a paper earlier this year calling for the government to spend $3 billion annually in pursuit of a modest goal: delaying the onset of age-related diseases by seven years.
They asserted that this would help to lay the foundation for a healthier and wealthier country, a so-called longevity dividend.
Dr. S. Jay Olshansky, an epidemiologist at the University of Illinois at Chicago, and one of the paper's authors said "The demographic wave entering their 60s is enormous, and that is likely to greatly increase the prevalence of diseases like diabetes and heart disease. The simplest way to positively affect them all is to slow down aging."