|Fitness Genome Map Updated|
By Nancy Touchette
August 7, 2003
uch attention has been focused on the human genome for what it can tell us about disease. But some researchers are looking at the genome from a different perspective. They would like to know which genes and gene variations can predispose us to fitness and good health.
The 2002 update to the human gene map for performance and health-related fitness phenotypes identifies studies of more than 100 genes and chromosomal regions reported over the past year that are thought to influence health, fitness, and athletic performance. This year’s update includes 14 genes in mitochondria—organelles that supply the cell with energy and contain their own genome. A total of 20 newly identified genes were added this year.
The fitness genome map is compiled annually by Claude Bouchard and his colleagues at the Pennington Biomedical Research Center in Baton Rouge, Louisiana, and is published in Medicine and Science in Sports and Exercise. Bouchard has been publishing an obesity gene map for the past 10 years. Three years ago, he decided that a similar review of fitness-related genes would be helpful.
“It appears to be meeting a need,” he says. However, he acknowledges that new approaches would help identify additional genes that affect fitness and health.
The researchers include in the map genes that have been shown to affect muscle strength and performance as well as cardiorespiratory endurance. Also included are genes that affect performance in elite endurance athletes and genes associated with a condition known as exercise intolerance, in which patients cannot endure any sustained physical activity.
Several studies focused on variations in the angiotensin-converting enzyme gene, ACE. This gene codes for a protein that affects blood pressure and electrolyte balance. The “I” form of the gene contains an insertion, and the “D” form contains a deletion. Previous studies have indicated that athletes with two copies of the I form may be better at sprinting, and people with two copies of the D form may excel at activities that require endurance.
This year’s fitness map cited data showing that among patients with congestive heart failure, those with two copies of the I form of the ACE gene tolerated exercise better and had a higher aerobic capacity than those with the D form.
British military recruits with two copies of the I form of ACE also responded better to training. And a study of older men with high blood pressure showed that those with the I/I form of the gene showed the greatest improvements in insulin sensitivity after a six-month exercise program compared with men with the D/D form.
The researchers note, however, that new approaches are needed to improve our understanding of how genes affect fitness. They suggest genome-wide scans to identify new genes and studies designed to look at how fitness-related genes are activated, or “turned on,” in response to exercise.
They also suggest identifying exercise-related genes in mice and using technologies to either knock out a gene or insert a new gene into mice to figure out how these candidate genes affect their function.
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