Restricting calories leads to a longer life

Image credit courtesy of Public Library of Science

Recent research supports the idea that eating less can help extend life. Eating well and nutritiously but in lesser amounts has been linked to a longer life and detaining the aging process.

A new report published in Science journal states that a reduced-calorie diet delays aging and slows down the onset of age related diseases such as diabetes, cancer and heart disorders.

The findings have been revealed by a team of researchers from the University of Wisconsin-Madison, the Wisconsin National Primate Research Center and the William S. Middleton Memorial Veterans Hospital.

The ongoing research has found that nutritious foods but less calories are the key to slowing down the aging process in a primate species, said Richard Weindruch. Weindruch is a professor of medicine in the UW-Madison School of Medicine and Public Health and leader of the National Institute on Aging-funded study. "We observed that caloric restriction reduced the risk of developing an age-related disease by a factor of three and increased survival." He added.

The study began in 1989 and has been conducted for a period of 20 years. During this time the monkeys that were fed a reduced-calorie diet have shown to live longer lives than the group that was given free reign to eat freely. Additionally, the research has also concluded that the brain health of the animals on the restrictive diet is also better.

Another study by a team of researchers from Pennington Biomedical Research Center came up with similar results. Anthony Cicitarese, Eric Ravussin and their colleagues have found that oxidative damage that has been linked to aging might explain how nutritious, but calorie limited intake can extend life.

A diet restricted in calories has shown to increase the life span of mice and delay age-related diseases in rodents. Hints are also shown that people who eat less calories may outlive those who overeat and their insulin sensitivity may not decrease as fast. Decreased insulin sensitivity is a precursor to diabetes.

The accumulation of 'oxidative damage' is a big factor in the decline of body functions due to aging. When food is converted to energy 'free radicals' are produced by the body's cellular structures, or mitochondria. Therefore, the theory that the Pennington researchers have come up with is that eating less calories lowers 'free radical' production by allowing a more efficient formation of mitochondria.

The team enlisted a group of 36 non-obese overweight young people for the study. The participants were divided into three groups, one that got 100% of their diet's energy requirements, a caloric restriction group (CR) and a caloric restriction plus exercise (CREX) group. Both the CR and CREX groups had a whole body 24hr decreased energy expenditures (calories burned overall) and both had increased numbers of mitochindia in their muscles. Both groups also had less DNA damage, which is a telltale sign of oxidative stress.

The results of the study also suggest that just a caloric restriction in a short period can be beneficial to good health. A long term sustained benefit has to be yet established, but by the statistics provided by these studies it is safe to remain optimistic on the issue.

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