Fish fat fights cystic fibrosis

Cystic fibrosis causes respiratory problems

Supplements of a fatty acid found in fish oil and breast milk could reverse the progress of cystic fibrosis (CF) by restoring the chemical balance of cells affected by the disease.

Research suggesting the therapy is effective was presented at the annual conference of the US Cystic Fibrosis Foundation in Seattle on Friday.

Doctors at the Beth Israel Deaconess Medical Centre in Boston believe the genetic condition may cause an imbalance in levels of fatty acids in cell membranes, and that this in turn causes the symptoms of disease.

They propose that by using supplements to restore normal levels of the acids they can reverse the effects of CF - an approach that was successful in tests on mice.

Glands malfunction

Cystic fibrosis is serious genetic disease that causes all the exocrine glands in the body to malfunction. These include sweat glands, the pancreas and glands that control mucus excretion.

The fat is also found in breast milk

CF patients have an average life expectancy of about 31 years, and are vulnerable to infection in the airways that can cause inflammation with the lung tissues becoming damaged.

Research to date has focused on developing gene therapy techniques or giving the patient antibiotics, but Dr Juan Alvarez and Dr Steven Freedman took a different approach.

"They've made some tantalising observations in an animal model," said Dr Peter Durie, director of cystic fibrosis research at the Hospital for Sick Children in Toronto, where the cystic fibrosis gene was discovered 10 years ago.

"No current therapy for cystic fibrosis deals with the underlying problem. Potentially, this is something closer to the fundamental problem."

Chemical levels

The researchers looked at differences in the relationship between levels of two fatty acids in normal mice and mice that had the genetic defect responsible for cystic fibrosis.

The cystic fibrosis mice had abnormally high levels of arachidonic acid (AA) and abnormally low levels of docosahexaenoic acid (DHA) compared to normal mice.

The imbalance was confined to the organs most affected by CF such as the lungs, pancreas, and intestine, and the researchers said a similar imbalance had been observed in humans with disease.

They gave the mice with the CF gene supplements of DHA and found this corrected the imbalance and reversed the signs of the disease in the affected organs.

Supplements

DHA is found naturally fish in oils and breast milk and supplements are available in health food shops - although the researchers warned that such supplements will not be effective at the recommended doses and could have serious side effects at high doses.

They are now working to develop a useful supplement for humans.

Dr Robert Beall, president of the Cystic Fibrosis Foundation, said: "Although a number of steps remain before the benefit of DHA to patients is known, this exciting research represents an entirely new strategy to correct and possibly even prevent some of the ravages of this disease."