Scientists have identified a gene that may play a key role in determining who has a heart attack or stroke.
Atherosclerosis is a major cause of heart attacks and strokes
Researchers in the United States say they have found a link between a gene called ALOX5 and atherosclerosis.
This condition, which causes the arteries to clog up, is the leading cause of heart attacks and strokes.
Writing in the New England Journal of Medicine, the researchers said the discovery could lead to new treatments to fight the condition.
The findings are based on a study of 470 utility workers in Southern California by researchers from the Keck School of Medicine at the University of California and the David Geffen School of Medicine at UCLA.
They recorded each participant's diet over 18 months and carried out tests to measure the build up of fatty acids in their arteries.
The researchers also took DNA samples from each of the volunteers. They used this to examine the ALOX5 gene in each of the participants.
A previous study in mice suggested that this gene may play a key role in the development of atherosclerosis.
The researchers found that people who did not have the common form of the ALOX5 gene were more likely to have thick artery walls - a symptom of atherosclerosis.
However, they also found that people with a high risk form of the gene - one in five of those involved in the study - could reduce their risk by eating certain foods.
They discovered that people with this form of the gene who ate "bad fats" or n-6 fatty acids - found in oils and eggs - were more likely to develop atherosclerosis.
However, those who ate "good fats" or n-3 fatty acids - found in fish like tuna and salmon - reduced their risk of developing the disease.
"One of the most interesting aspects of this new finding is that the effect of the ALOX5 gene on atherosclerosis depends upon diet," said Professor James Dwyer of USC.
"The adverse effect of this gene is increased by dietary intake of certain n-6 polyunsaturated fats, while the adverse effect is blocked by intake of fish oils containing n-3 polyunsaturated fatty acids."
The scientists believe the ALOX5 gene converts "bad fats" into molecules that serve to clog up the arteries and cause atherosclerosis.