March 23, 2004 -- Cutting back on calories, even late in life, may help slow the aging process and delay death, according to a new study in mice.
Previous studies have suggested that calorie restriction, defined as a reduction in calorie consumption without reaching malnutrition, may slow down the aging process and decrease the risk of developing age-related diseases, but only if started early in the life of mammals, such as mice and possibly humans.
But in this study, researchers say they've found proof that it's never too late for mice to start calorie restriction and reap the health benefits.
The study showed that mice that began calorie restriction late in life enjoyed the benefits almost immediately. Their life span was extended by about six months, and deaths due to cancer were delayed.
Researchers say the findings suggest that calorie restriction results in changes in gene activity that might fight the effects of aging. Of course, many more studies will be needed to see if calorie restriction might have the same effects in humans.
Calorie Restriction May Slow Disease
In the study, published in the March 22 early edition of the Proceedings of the National Academy of Sciences, researchers looked at the effects of calorie restriction in 19-month old mice, which is the human equivalent of late middle age.
The study showed that calorie restriction in the mice began to produce health benefits within two months and increased the average time to death by 42%. This change resulted in an increase in life span by six months.
In addition, when the researchers looked at genes from old mice placed on regular diets who were later switched to a calorie-restricted diet, their gene profile changed to resemble those seen in mice that began calorie restriction early.
Researchers say these changes in the genes appear to delay the onset as well as slow the progression of age-related diseases, such as cancer.
When the mice went back to a regular diet, the changes induced by calorie restriction disappeared, and genes returned to normal.
Researchers say the results suggest that there is a close relationship between calorie consumption, the speed of the aging process, and gene patterns. They say future drug therapies that mimic the changes created by calorie restriction may one day be able to produce the same age-fighting effects.