Benefits of omega-3 fatty acids tally up

Promising news about omega-3 fatty acids just keeps rolling in. A new study bolsters previous data suggesting that fish oil supplements high in omega-3s may benefit critically ill people in intensive care units by quelling inflammation. Meanwhile, another study finds that robust omega-3 levels protect the ends of chromosomes from damage, which suggests a benefit against age-related diseases.

Omega-3s are found naturally in fish, walnuts, certain vegetable oils and many other foods.

In a study in Critical Care posted online January 19, a team of British and Portuguese scientists tested the value of fish oil supplements in 23 people admitted to Padre Américo Hospital in Penafiel, Portugal. The patients were critically ill with sepsis, a life-threatening overreaction to a microbial infection spread in the blood. Although doctors use a host of drugs and around-the-clock care to treat sepsis, the death rate is still shockingly high, up to 35 percent.

These patients were fed intravenously with a mix of proteins, carbohydrates and fats. The researchers randomly assigned 13 to receive soybean oil and fish oil as their daily fat intake, whereas the other 10 received only soybean oil as their dietary fat component, with total oil amounts about equal between the two groups. All were on a ventilator to assist breathing, says study coauthor Philip Calder, a biochemist at the University of Southampton in England.

After four weeks of treatment, four people in each group had died. Excluding those eight, the patients who received the fish oil recovered and were discharged from the hospital in a median of 28 days, compared with 82 days for those getting soybean oil only.

A hallmark of sepsis is uncontrolled inflammation that is so intense that it threatens vital organs, including the lungs. Tests showed that patients receiving fish oil showed signs of reduced inflammation and, possibly because of this, processed oxygen better, Calder says.

In the other new research, scientists investigated the effect of omega-3s on telomere length. Telomeres are the strings of repeating DNA sequences at the ends of chromosomes that are thought to keep them from fraying during cell division. “In cells, telomere length is a big determinant of aging,” says cardiologist Ramin Farzaneh-Far of the University of California, San Francisco.

If telomeres shorten too much, they stop functioning as DNA safeguards and the cell dies, he says. Some clinical studies have linked telomere shortening to earlier death.

Farzaneh-Far and his colleagues recorded telomere length in white blood cells of 608 people with heart disease and an average age in their mid-60s. The researchers also noted how much omega-3 fatty acid was in the bloodstream of each participant.

Although some people had higher omega-3 levels than others at the outset, telomere length wasn’t markedly different between the groups at that time.

But after five years, participants who started out with higher levels of omega-3s had experienced substantially less telomere shortening than the others, the researchers report in the Jan. 20 Journal of the American Medical Association. The researchers accounted for baseline telomere length, gender, ethnicity, education level, smoking status, medications and previous heart attacks in the volunteers.

“Given the increasing evidence for an association between telomere length and cardiovascular and other age-related diseases, the finding could provide a novel mechanism which explains the potentially protective effects of omega-3 fatty acids on these diseases,” says cardiologist Nilesh Samani of the University of Leicester in England. But Samani finds it odd that the telomere length wasn’t different at the outset, since some patients had more omega-3 fatty acids than others.

The American Heart Association generally recommends eating two fish meals per week, and that cardiac patients consume 1 gram of omega-3 fatty acids per day. These researchers agree that it can’t hurt. ”The good side of this is that [omega-3s] are naturally occurring things,” Calder says.