Researchers, led by Anthony E. Civitarese of the Pennington Biomedical Research Center (Baton Rouge, Louisiana), have shown that tests performed on mice parallel a study they performed on overweight people.

The Civitarese team randomly studied 36 overweight people. One group ate 25% less calories than their normal intake of food and a second group used a diet that included 12.5% less caloric intake than normal and exercised to burn off another 12.5% of their calories. The third group ate what the research team called a weight-maintenance diet.

Their study is based on previous studies that show the number of mitochondria (cell bodies that produce enzymes for metabolic conversion of food to energy) decrease as people get older and that, as a result, free radicals (highly reactive molecules) are increased in numbers. What this does, scientists believe, is to damage DNA (deoxyribonucleic acid) in the body—which is what carries our genetic material and is important to well-being and health.

After six months, members of the first two groups (the dieting groups) displayed, on average, a 20 to 35% increase in the number of mitochondria in their muscle cells and a 60% decrease in damage to DNA. Also, genes related to mitochondria showed increased vitality. One of these genes is called SIRT1 (short for “silent mating type information regulation 2 homolog 1”). SIRT1 is an enzyme that, basically, reacts to stress and longevity.

Additional studies are underway based on this study. And, companies are developing drugs to activate SIRT1. Civitarese’s study seems to show a correlation between eating a limited amount of balanced, nutritious food and living a healthier life. And maybe it also means living a longer life, too!

The article “Calorie Restriction Increases Muscle Mitochondrial Biogenesis in Healthy Humans” based on Civitarese's study appears in the March issue of Public Library of Science’s PLoS Medicine. A copy of it appears at: http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pmed.0040076.

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Biology  Genetics  Research  Science  William Atkins