TUESDAY, Jan. 19, 2010 (HealthDay News) -- Scientists think they have uncovered at least one of the reasons why omega-3 fatty acids are good for your heart.
The more omega-3 that patients with coronary heart disease consumed, the slower their telomeres shrank. Telomeres are structures at the end of a chromosome that get shorter the more times a cell divides, making them a marker of biological age.
"We're certainly not saying that this is the reason for all the benefits of omega-3 fatty acids, but it is a new pathway linking omega-3 fatty acids to biological aging in these patients," said study lead author Dr. Ramin Farzaneh-Far, an assistant professor of medicine at the University of California, San Francisco.
The findings are published in the Jan. 20 issue of the Journal of the American Medical Association.
"What they're really saying is that there is quite an impact of omega-3s on cell support and cell functioning," said Dr. Suzanne Steinbaum, a preventive cardiologist at Lenox Hill Hospital in New York City and a spokeswoman for the American Heart Association. "If you supplement with omega-3s or eat omega-3s, your cells stay healthier, your cells age less quickly."
Said Farzaneh-Far: "Cardiologists have known for about 20 years that increased dietary intake of omega-3 fatty acids are beneficial for patients with coronary artery disease, particularly those who have had a prior heart attack. It reduces the risk of subsequent heart attacks and death."
But the reasons for that benefit have not been well defined, said John Bowman, an associate professor of pharmacy practice at Texas A&M Health Science Center Irma Lerma Rangel College of Pharmacy. "We don't know the exact cellular mechanisms," he said.
Omega-3 fatty acids are plentiful in fatty fish like salmon, mackerel, herring, lake trout, sardines and albacore tuna, according to the American Heart Association.
For the new study, the researchers followed about 600 patients in the San Francisco Bay Area with coronary artery disease. Blood levels of omega-3 fatty acids and telomere length were measured at the beginning of the study and again about five years later.
"That allowed us to measure the change in telomere length over five years and see if that bore any association with levels of omega-3 fatty acids at the beginning of the study," Farzaneh-Far said.
And, indeed, there was a relationship.
"We found that as blood levels of omega-3 went up, the rate at which telomeres shortened decreased," Farzaneh-Far said. "To the extent that that is a marker of biological aging, the rate of biological aging went down."
The findings don't change current recommendations regarding omega-3 fatty acids or what people should be doing.
"The American Heart Association recommends that those with coronary heart disease get about a gram a day of omega-3 fatty acids," said Farzaneh-Far. "Our study certainly doesn't suggest any change in that."
Dr. Melissa Tracy, medical director of cardiac rehabilitation at the University of Miami Miller School of Medicine, said the new study gives "some additional support to the use of omega-3 fatty acids." But, she noted, it's unclear how far these findings could be extrapolated to other groups of people, such as those who don't have coronary artery disease.
"There are other extraneous circumstances which can impact telomere length," she said.
And, Tracy added, "we should try to do as much with our own bodies that we can. I am an advocate of proper diet, exercise, for optimizing your lifestyle, meaning reducing stress and getting enough sleep."
The American Heart Association has more on omega-3 fatty acids.