Cutting calories late in old age may lead to a longer life, at least in mice, researchers report. Although studies have shown that mice put on a reduced-calorie diet early in life live longer than normal mice, this is the first study to show that calorie restriction can have the same effect when started late in life.
Reducing caloric intake in mice, even in old age and provided the mice are not already lean, may be effective at improving health and increasing their lifespan, the researchers noted. And this may be true for humans as well. The research in mice may help scientists discover a new category of drugs that delay aging by producing the same genetic effects as calorie restriction.
Studies in a wide range of organisms, including yeast, rodents and dogs, have suggested that a reduced-calorie diet, as long as it provides adequate nutrition, can lead to longer lifespans. Calorie restriction has been shown to delay and prevent age-related diseases, including cancer.
Calorie restriction is thought to produce health benefits by changing the normal expression of a variety of genes. The conventional wisdom has been that calorie restriction is less effective when started later in life.
The scientists studied the effect of calorie restriction in mice that were 19 months old - a few months before age-related deaths begin to affect mice. Compared to mice that were fed a normal diet throughout their lives, mice switched to the reduced-calorie diet developed fewer tumours and lived longer. The beneficial effects of calorie restriction kicked in soon, according to the report. Researchers detected differences as soon as two months after the mice were switched to a reduced-calorie diet.
What's more, they found that mice experienced changes in the expression of several genes soon after going on the leaner diet. The affected genes included genes involved in cell growth and proliferation. When mice were switched back to a normal diet, however, most of this gene expression returned to normal.
All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.