Fish fats may improve a leading cause of disability and death
by Craig Weatherby
Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the U.S., but if you’ve never heard of it, you have plenty of company.
Some 16 million Americans suffer from one or more of the lung diseases that produce the cluster of symptoms called COPD.
Smoking causes up to 90 percent of COPD cases in the U.S., but in developing countries, air pollution is a major cause or contributing factor.
According to the findings of a recent study in which researchers surveyed more than 18,000 adults aged 20-44 in Europe, the U.S., Scandinavia, Australia, and New Zealand, as many as one in nine is at risk for developing COPD. The survey results also indicate that initial symptoms of COPD develop much earlier than thought, and that a growing number of young adults—smokers, for the most part—are already on track to develop irreversible COPD later in life.
Most people experience a natural decline in lung capacity in their mid-30s, with nonsmokers about two tablespoons of air-holding capacity annually. But smokers lose three to four tablespoons of their lung capacity every year, which dramatically increases their risk of death and disability.
The symptoms of COPD, which include the following, are often mistaken for normal age-related decline in lung function:
- Persistent cough, with increased sputum (phlegm) production
- Shortness of breath during physical exertion
These changes manifest slowly over time, so only 25 to 50 percent of those with the disease are aware of it, while the majority don't receive a COPD diagnosis until they are hospitalized. By the time most COPD patients seek medical attention—typically during their mid-50s—they’ve already lost up to half of their lung function.
Omega-3s may offer first COPD treatment
Earlier this month, Japanese researchers published the results of a small study of 64 adults with COPD. They reported that omega-3 fatty acid supplements appeared to alleviate patients' breathing difficulties, probably by damping the airway inflammation characteristic of COPD.
Half of the patients drank a liquid supplement rich in long-chain marine omega-3s daily, while the other half drank a supplement containing the omega-6 fats that predominate in most common vegetable oils, processed foods, poultry, and meats.
After two years, patients in the omega-3 group scored significantly better on a test that measures breathing during six minutes of walking, while the omega-6 group did not. Likewise, levels of key inflammatory messenger chemicals declined only in the blood and mucus of the omega-3 group.
Specifically, the researchers measured lower levels of leukotriene B-4, tumor necrosis factor-alpha and interleukin-8 in the omega-3 group. The inhibitory effect of omega-3s on levels of these inflammatory cytokines and prostaglandins supports the idea that the lung function improvements recorded stemmed from the fish fats’ anti-inflammatory effects.
As the Japanese researchers concluded, “We suggest nutritional support with an omega-3 PUFA-rich diet as a safe and practical method for treating COPD.”
Larger, longer studies are needed to confirm the results. But, the new findings make sense in light of the inflammatory nature of COPD and the positive effects long-chain marine omega-3s exhibit in childhood asthma: another inflammatory lung condition. (To read our report on a study of omega-3 therapy in asthma, click here.)
- Matsuyama W, Mitsuyama H, Watanabe M, Oonakahara K, Higashimoto I, Osame M, Arimura K. Effects of Omega-3 Polyunsaturated Fatty Acids on Inflammatory Markers in COPD. Chest. 2005 Dec;128(6):3817-27.
- de Marco R, Accordini S, Cerveri I, Corsico A, Sunyer J, Neukirch F, Kunzli N, Leynaert B, Janson C, Gislason T, Vermeire P, Svanes C, Anto JM, Burney P; European Community Respiratory Health Survey Study Group. An international survey of chronic obstructive pulmonary disease in young adults according to GOLD stages. Thorax. 2004 Feb;59(2):120-5.