The similar findings in the two studies half a world apart are noteworthy, Carnethon said. "We are always happy to see findings replicated by different investigators in different settings," she said.
Meanwhile, researchers are reporting a different built-in mechanism that protects a lucky few individuals from heart disease -- a genetic mutation that seems to reduce blood levels of the fats called triglycerides.
The mutation was found in members of the Old Order Amish community in Pennsylvania, said the lead investigator, Toni I. Pollin, an assistant professor of medicine at the University of Maryland School of Medicine.
Pollin and her colleagues looked through the complete genetic complement of more than 800 members of the Amish community. "We looked at genes involved in the response to dietary fat," she said. "One region came up strong on chromosome 11. This genetic marker was not too far from a cluster of genes involved in lipid metabolism."
The researchers closed in on one gene, designated APOC-3, according to a report in the Dec. 12 issue of the journal Science. That gene makes a protein that inhibits the breakdown of triglycerides. About 5 percent of the Amish in the study had a mutated form of the gene that limited production of the protein, and so they had low blood lipid levels.
"It is an apparent cardioprotective mechanism," Pollin said. "It raises the hope that by decreasing production of APOC-3 it could potentially be therapeutic."
It's possible that a drug designed to target the gene could be used to reduce levels of blood fats and thus reduce coronary risk, Pollin said.
The mutation has not been found outside the Amish community, Pollin said. "We have looked at 200 healthy individuals and have not found it, she said.
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