So says a new study by researchers at the Department of Energy's Lawrence Berkeley National Laboratory and the Children's Hospital Oakland Research Institute (CHORI), conducted by Paul Williams of Berkeley Lab's Life Sciences Division in collaboration with Robin Rawlings and Patricia Blanche of CHORI and Ronald M. Krauss of CHORI and Berkeley Lab's Genomics Division. They report their findings in the July 8, 2005, issue of the American Journal of Clinical Nutrition.
The investigators analyzed how "bad" cholesterol (low-density lipoprotein, or LDL, cholesterol) responded to diets that were either high or low in fat in 28 pairs of identical male twins -- one twin a vigorous exerciser, the other a comparative couch potato.
"Although identical twins share exactly the same genes, we chose these twins because they had very different lifestyles," says Williams. "One member of each pair was a regular long-distance runner, someone we contacted through Runner's World magazine or at races around the country. His brother clocked 40 kilometers a week less, at least, if he exercised at all."
For six weeks the twins ate either a high-fat diet (40 percent of its calories from fat) or a low-fat diet (only 20 percent of its calories from fat); then the pairs switched diets for another six weeks. After each six-week period the twins' blood cholesterol levels were tested.
The researchers were interested in learning if blood cholesterol changes due to the different diets would be the same or different in each pair of genetically identical twins, even though their lifestyles were very different. A correlation o
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Contact: Paul Preuss
paul_preuss@lbl.gov
510-486-6249
DOE/Lawrence Berkeley National Laboratory
8-Jul-2005