Blame Genes for Poor Cholesterol

Genetics may be a reason why blood levels of low-density lipoprotein("bad") cholesterol vary greatly between individuals. To investigatethe gene link, researchers studied the responses of 28 pairs ofidentical male twins with diets either high or low in fat; one brotherwas a devoted exerciser while the other one was a "couch potato."

During the first 6 weeks, the participants ate either a low-fatdiet (20% of the calories from fat) or a high-fat diet (40% of thecalories from fat). The twins switched diets for the latter 6 weeksof the study. After each 6-week period, the twins' blood cholesterollevels were checked. The results of the study indicated astrong similarity in the way each twin responded to the diets,regardless of whether he exercised or not.