The latest scientific spin on the fountain of youth is not drinking magic water, but cutting back on regular food. Although there has been considerable success with animals in lab settings, it seems uncertain whether humans can voluntarily maintain such a restrictive diet on their own over an extended period of time.
Based on animal studies, calorie restriction might lengthen human life to about 112 healthy years, according Dr. Richard A. Miller, a pathologist at the University of Michigan.
At the Wisconsin National Research Center, rhesus monkey Matthias, 28-years-old, has already beaten the 27-year average life span of laboratory monkeys, but time has taken its toll via hair loss, a slight potbelly and abundant facial wrinkles. His neighbor, Rudy, is the picture of youth and health—thin and full of vitality, with a sleek coat—and also slightly older. Rudy, who has lived on a calorie-restricted diet, eating about 30 percent less calories than Matthias while still receiving adequate nutrition, is in a position to live a very healthy, unnaturally long life.
Other monkeys on the same restricted diet share the same promising results with Rudy. While monkeys like Matthias suffer signs of advanced aging like humans, including three cases of diabetes, five cancer deaths and one disease-related death, none of the monkeys with restricted diets have suffered from diabetes, and only three have died of cancer.
However, studies of the effects of calorie restriction on health and life expectancy are not new. In 1935, Cornell nutritionist Dr. Clive McCay found that mice fed 30 percent fewer calories lived about 40 percent longer lives. These mice were more active and more immune to disease than mice that consumed as much as they wanted.
As promising research results accumulate, more and more scientists join the efforts to test the experiments in life expansion. Considering members of the baby boomer generation are approaching their 60s and 70s, the pertinence of this research is increasing. In the next 25 years, the number of Americans 65 and older will double, according to government census data.
“The demographic wave entering their 60s is enormous, and that is likely to greatly increase the prevalence of diseases like diabetes and heart disease,” said Dr. S. Jay Olshansky, an epidemiologist at the University of Illinois at Chicago, who has collaborated with Miller. “The simplest way to positively affect them is to slow down aging.”
Human results from the caloric restrictions exist but are much more limited. In the April 5th issue of the Journal of the American Medical Association, Louisiana State University researchers published reports of human subjects on low-calorie diets who had lower insulin levels and body temperatures than those on normal diets. Insulin levels and body temperature are both possible markers of life span and indicate chromosomal damage that is usually linked to aging.
Outside the laboratory, some people have adopted a permanent low-calorie diet in the hopes of prolonging healthy life. Mike Linksvayer, 36, who has followed a low-calorie diet, says he has never experienced better health and has an admirable blood pressure of 112 over 63.
Despite great health results, is Linksvayer’s lifestyle too extreme? He is 6 feet tall and weighs only 135 pounds. A picture of him reveals a very slender, almost gaunt frame. Not only does he have minimal fat, but also minimal muscle. He says that he consumes an average of 2000 to 2100 calories per day; breakfast is an apple or some cereal, lunch is a small vegan dish, and dinner is whatever his wife makes, excluding whatever Linksvayer considers unhealthy, like bread, rice and sugar. Sometimes, on the weekends, he likes to fast.
Exclusion of major food groups, obsessive calorie counting, extreme slenderness and fasting sound like symptoms of an eating disorder, particularly anorexia. It is one thing when lab researchers can perfectly administer food rations with the 30 percent calorie restriction and 100 percent nutrients to animals. However, people would have to regulate their own diet, which requires extreme discipline over extended periods of time. Such effort and pressure to keep to the diet could morph into an eating disorder.
Just like losing excess weight, restricting diet for the goal of a longer, better life can turn into an unhealthy eating disorder. Human nature is just as vulnerable to obsession with prolonged youth and life as it is with beauty and self-image.
