Jan 19, 2010 – Patients with heart disease with the highest blood levels of omega-3 fatty acids appear to age more slowly than those with the lowest blood levels, according to a new study.
Previous studies have shown that heart disease patients high in omega-3 fatty acids – found in fish and in supplements – have higher survival rates.
The new study can help explain why. “We have shown an entirely new effect of omega-3 fatty acids that may slow the biological aging process in patients with coronary artery disease,” said lead author Ramin Farzaneh-Far, MD, assistant professor of medicine at the University of California San Francisco.
Farzaneh-Far and colleagues studied a marker of biological age – the rate at which telomeres shorten, structures at the end of a chromosome that are involved in its replication and stability. As telomeres shorten over time, the ultimate result is cell death, scientists believe.
In previous research, Farzaneh-Far says, his team examined the same group of patients with heart disease and found that telomere length is “a strong predictor of death and poor outcomes” [from heart disease]. In this [study], we found the shorter your telomeres, the greater the risk of death. “
In the new study, the higher the blood levels of omega-3 fatty acids in the patients, the slower the telomere shortening rate.
“We looked at the biological effects of higher blood levels,” Farzaneh-Far tells WebMD, “not taking supplements.”
The study is published in the Journal of the American Medical Association.
Details of the omega-3 and aging study
For the study, the researchers evaluated 608 patients with stable heart disease who were recruited from the Heart and Soul Study of September 2000 and December 2002, and monitored them over a median of six years (half were observed more, the other half less) .
At the start of the study, participants gave blood samples that were tested for omega-3 fatty acid levels. The researchers also isolated DNA from the blood and evaluated the length of the telomere in leukocytes, a type of blood cell.
During the follow-up period, “patients with the lowest levels of omega-3s in their blood had telomere shortening 2.6 times faster than those with the highest levels of omega-3s,” Farzaneh-Far told WebMD.
How is this related to aging? “We don’t have enough data to convert the changes in telomere shortening into years of aging,” he says. “This could be one of the first studies to look at changes in telomere length over time.”
No relationship was found between omega-3 fatty acid levels and telomere length at baseline. Researchers aren’t sure why, but they state that omega-3 fatty acid levels are one of many influences on telomeres length, along with other factors such as inflammation in the body, obesity, oxidative stress, and lack of physical activity.
Would High Blood Omega-3 Levels Help People Without Heart Disease? Farzaneh-Far cannot tell. “I simply cannot say whether this effect of omega-3 fatty acids on telomere length is present in people without coronary artery disease,” says Farzaneh-Far, noting that this is beyond the scope of the study. However, he adds, “it could be.” Telomere shortening happens in everyone, he says.
Omega-3 Fatty Acids & Aging: Different Opinions
“This is very exciting news to show how fish oil works at the cellular level,” says Ravi Dave, MD, cardiologist at Santa Monica-UCLA Medical Center & Orthopedic Hospital and Associate Professor of Medicine at the University of California Los California Angeles David Geffen School of Medicine.
The new result, he tells WebMD, builds on previous research. “A strong association has been found that ingesting omega-3s from the sea reduces the risk of cardiovascular disease.”
Researchers have been trying to find out why. Several proposed mechanisms have been found, including reducing inflammation in the body or reducing the risk of abnormal heart rhythms, says Dave.
With the new knowledge, he says, “it’s no longer a hypothetical mechanism. It has a basis for how it works.”
But, he adds, “Fish oils are just one of the things that affect telomere length.” Many other factors, he says, play a role, such as oxidative stress on the cells.
Finally, says Dave, if telomere research is confirmed, a test to check a person’s telomere length could be a way to predict heart disease risk.
The new research shows fish oil protective effects on the aging clock, adds Robert Zee, PhD, assistant professor of medicine at Harvard Medical School and director of molecular epidemiology in the preventive medicine department at Brigham & Women’s Hospital in Boston. He has reported an association between shorter telomere length and heart attacks. But the new findings need to be replicated, he says.
Omega-3 Fatty Acids and Health: Advice
What should healthy people and those with heart disease do with regard to omega-3 fatty acids?
Farzaneh-Far draws attention to the existing guidelines of the American Heart Association. “The American Heart Association already recommends at least one gram a day” of omega-3 fatty acid intake for people with documented heart disease, he says. Preferably, according to the AHA, it should come from oily fish like salmon, mackerel, or albacore tuna, but supplements could be considered if the patient’s doctor agrees.
For those who don’t have heart disease, the AHA recommends eating a variety of fish, preferably oily species like salmon, and healthy oils like flaxseed, canola, and soybeans at least twice a week.
One of the researchers, William S. Harris of the University of South Dakota, reports that he has received research grants from companies interested in omega-3 fatty acids. Another co-author, Elizabeth H. Blackburn, PhD, received the 2009 Nobel Prize in Physiology or Medicine for discovering how chromosomes are protected by telomeres and the enzyme telomerase.