Expert Says Diet, Exercise Don’t Extend Life Span
Diet, exercise and vitamins have no proven value in helping people extend their life spans, the deputy director of the National Institute on Aging said Wednesday.
The medical profession does not know of any definitive way to slow the aging process, conceded Dr. Edward L. Schneider, who warned that “medical quackery is a multibillion-dollar industry” featuring claims for increasing life span.
Maximum Human Age
Life span--the maximum age a human can attain--is about 115 years and has not changed appreciably in the last century, Schneider said.
Life expectancy, on the other hand, is the average number of years a person is likely to live--now 71 years at birth for men and 78 years for women. Because of improvements in public health measures and in the treatment of heart disease and cancer, life expectancy has increased dramatically since 1900, when it was only about 45 years.
Schneider offered a personal prescription for living longer: “Take a vacation, go to a good restaurant”--or do anything else that helps you to relax.
After an extensive review of medical research, Schneider said, he has concluded that there are no scientifically valid methods of increasing the human life span. He said that he wrote an article for the New England Journal of Medicine and conducted a special news conference Wednesday “because I was concerned about the false and misleading claims for products that are promoted to extend life span.”
Restricting Calories
Although people can take steps that might help their state of health, there is nothing certain to delay the date of death, according to Schneider. For example, he said, eating less helps animals live longer in laboratory experiments, but that may not be true of humans.
“If you’re a mouse or a rat, I can tell you, if you restrict calories, you’ll live longer,” Schneider said. “I can’t tell you that if you’re human.” Life insurance company records show that those with the highest risk of early death are the heaviest and the thinnest, he said.
The promotion of exercise as life-enhancing is strictly a late-20th-Century belief, Schneider said. “Last century, it was thought exercise was detrimental . . . so the rich and the educated didn’t exercise very much,” he said. “Now there’s . . . a tremendous business in health spas.”
Studies of Athletes
However, studies of college athletes, and of other persons who exercised their entire lives, showed no extra longevity compared with more sedentary citizens.
But exercise is worthwhile because it can help specific organ systems, Schneider stressed: It can improve heart and lung function, improve muscle tone and “most importantly, slow the loss of bone that occurs in aging women.” An epidemic of osteoporosis--a disease characterized primarily by hip fractures in older women--exists in the United States, he said.
Dependence on vitamins also is futile for those who want to live longer, he said, noting that laboratory studies in which animals are given large amounts of vitamins A, C and E show “no consistent trend” toward increased life span. He cautioned also against the health dangers of taking excess amounts of vitamins, saying some persons mistakenly believe that, if a small amount is good, a massive dose would be even better. Instead, the overdose of vitamins could bring on illness and bodily damage.
The National Institute on Aging, a 10-year-old federal agency, spends $144 million a year on learning about the process of growing older. Schneider, 45, was asked how he hopes to extend his life span: “I want to do a lot of sailing and skiing and try to enjoy life to the fullest.”
