Longer Life with Lower Calories
(Ivanhoe Newswire) -- Rodents and some other short-lived species are known to live longer when they cut calories, but what about humans? A new study out of Louisiana State University reveals cutting calories may also help people live longer lives.
It's believed cutting calories impacts metabolism, which also means it alters insulin sensitivity, neuroendocrine function, stress response, or a combination of these. Leonie K Heilbronn, Ph.D., and colleagues set out to test this theory with and without the addition of exercise in non-obese individuals.
The research involved 48 healthy, sedentary men and women. The study participants were randomly placed into one of four groups: The first group followed a weight maintenance diet, the second group followed a diet with a 25-percent calorie restriction, the third group followed a calorie restriction diet combined with exercise, and the fourth group followed a very low-calorie diet in combination with a weight maintenance diet.
When the participants were analyzed again six months later, the researchers noted significant decreases in energy expenditure in all but the control group. There was also a reduction in DNA fragmentation in the groups who had a reduction in their caloric intake, which indicates less DNA damage in those individuals.
A similar, but longer-term study, found encouraging results as well. After six years on a calorie-restricted diet, researchers from Washington University School of Medicine in Seattle found study participants had hearts that functioned like the hearts of much younger people.
Another study referenced in an editorial in this week's Journal of the American Medical Association, also found mice and rats could have their lifespan extended by 30 percent through consistent caloric restriction.
While researchers say the results uphold their theory, they stress the need for longer-term studies to truly determine if these effects produce changes in the human aging process.
SOURCE: The Journal of the American Medical Association, 2006;295:1539-1548
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