Marine oil supplement fails to produce beneficial results in non-asthmatic elite runners: RCT
Habitual endurance training may be linked to mild airway inflammation and subsequent deterioration in lung function. At the same time, PCSO-524 — also called Lyprinol or Omega XL — a supplement extracted from Perna canaliculus (NZ green-lipped mussels), has been "shown to moderate airway inflammation in asthmatic subjects".
Based on this, researchers at Indiana University and the University of Alabama conducted a study to determine if supplementation with PCSO-524 could improve pulmonary and respiratory muscle function in non-asthmatic elite runners.
States of supplementation
They recruited 16 non-asthmatic elite male runners and randomly assigned them to either a treatment group or placebo group.
Each participant in the treatment group received eight capsules of PCSO-524 daily, each capsule containing 50mg of omega-3 polyunsaturated fatty acids and 100mg of olive oil. Each participant in the placebo group received eight capsules daily as well, though each one contained 150mg of olive oil.
The supplementation period lasted 12 weeks, during which the participants' resting pulmonary and respiratory muscle function was tested every two weeks (after being tested at baseline).
Subsequently, the researchers reported no significant main effects between or within the subjects in the following states:
- forced vital capacity (FVC), the maximum volume of air that can be forcibly expelled after full inhalation)
- forced expiratory volume in 1 second (FEV1), the volume of air that can be forcefully expelled in one second of the FVC test
- forced expiratory flow from 25% to 75% of lung volume (FEF25-75), the speed of air exiting the lungs during the middle portion of a forced expiration
- peak expiratory flow rate (PEFR), the maximum speed of expiration
- maximal voluntary ventilation (MVV), a measure of the maximum volume of air that can be inhaled and exhaled within one minute
- maximal inspiratory mouth pressure (PImax), the most common measurement of inspiratory muscle strength
- closing volume, the volume of lung inflated when small airways in the lungs' dependent parts of start to collapse during expiration
However, there was a significant effect noted within the subjects when it came to the following states:
- maximal expiratory mouth pressure (PEmax), the most common measurement of expiratory muscle strength
- lung diffusion capacity (DLCO), the extent to which oxygen passes from the lungs' air sacs and into the blood
The only significant interaction observed was a treatment by time interaction in FEF25-75 and DLCO, leading the researchers to say PCSO-524 supplementation did not improve pulmonary or respiratory muscle function in the subjects.
Mussels not useful for muscles?
The results contradicted those of previous studies, where PCSO-524 had been found to reduce inflammation markers in the airways of asthmatic subjects.
The researchers said it was likely that the participants in the current study had a "high capacity to mitigate airway inflammation induced by running exercises, and therefore, did not experience any additional beneficial effects supplementing with the marine oil extract".
They added that it was possible the participants were not significantly affected by exposure to mild seasonal changes and airborne pollutants that usually induce bronchial hyper-reactivity in asthma sufferers.
As such, they may not have experienced noticeable airway inflammation, even during periods of sustained exercise.
However, the researchers did not measure inflammation and were thus unable to confirm the presence or severity of airway inflammation in the study subjects, or the resultant impact of PCSO-524 supplementation.
They also did not evaluate the effects of airborne pollutants or mild season changes, both factors that might have influenced the study's results.
They concluded: "Future studies should aim to confirm the presence and evaluate the severity of airway inflammation in elite runners during a period of intensified training, and the effect of marine oil extract supplementation on those symptoms and the resulting athletic performance.
"We have demonstrated that there did not appear to be any positive effect of supplementation with PCSO-524, a marine oil lipid extract derived from the New Zealand green-lipped mussel (Perna canaliculus), on resting pulmonary and respiratory muscle function in non-asthmatic elite runners.
"Therefore, non-asthmatic elite runners aiming to optimise resting pulmonary function through nutraceutical supplementation are unlikely to obtain any benefits from using this marine oil extract."
Source: International Journal of Exercise Science
Vol. 11, Issue 1
"The Effects of PCSO-524®, a Patented Marine Oil Lipid derived from the New Zealand Green Lipped Mussel (Perna canaliculus), on Pulmonary and Respiratory Muscle Function in Non-asthmatic Elite Runners"
Authors: Ren-Jay Shei, et al.
