Omega-3 fatty acids can improve COPD symptoms

A diet rich in omega-3 and polyunsaturated fatty acids (PUFAs) could improve lung function for COPD sufferers, reports a study from Japan.

"Nutritional support with an omega-3 PUFA-rich diet decreased serum andsputum levels and improved symptoms [for people with chronic obstructivepulmonary disease (COPD)]," said the researchers from KagoshimaUniversity Hospital.

COPD mainly affects smokers, and is the number five cause of deathworldwide. It is characterised by chronic inflammation in the small airwaysof the lung and leads to excessive mucus production, excessive fibrousconnective tissue development (fibrosis), and degradation of proteins(proteolysis). There is no cure.

The two-year Japanese study, published in the journal Chest (vol 128, no 6, pp 3817-3827), followed 64 patients with COPD. The patients wererandomly divided into two groups; one received an omega-3 PUFA rich diet,and the other ate a normal diet. Results were quantified in terms of levelsof inflammatory markers, exercise capacity, and shortness of breath.

The nutritional support consisted of a mixture of omega-3 and omega-6 fattyacids, including lanoleic acid (LA), and alpha-linolenic acid (ALA), aprecursor for docosahexaenioc acid (DHA) and eicosapentaeoic acid (EPA).

After 15 months, levels of leukotriene B4 (LTB4), a marker for inflammation,were significantly lower for the patients receiving the fatty acid enricheddiet. Shortness of breath also decreased, while the control group showed noimprovement.

"Nutritional support with an omega-3 PUFA-rich diet had anti-inflammatoryeffects and improved exercise tolerance," said the researchers.

The role of the fatty acids is suspected to be complex. The scientistspropose that the omega-3 PUFAs affect cellular signalling and geneexpression activities. They are also suggested to affect other inflammatorycytokines. A larger study and longer follow-up period should be conducted,said the researchers.

Omega-3 fatty acids are found naturally in foods such as fish, canola oiland walnuts. Previous studies have linked it to improved behaviour inchildren, reduced loss of brain function in the elderly, and loweredincidence of postnatal depression in mothers.

Earlier research from Indiana University had showed omega-3 supplementscould reduce symptoms associated with asthma and exercise-inducedbronchoconstriction (EIA).

Omega-3 supplementation of products has been a major growth area in theneutraceutical market. Mintel's Global NewProducts Database (GNPD) showed a 36 per cent increase in omega-3-containingproduct launches across Europe in 2005.