Results published in the Journal of Functional Food indicated that six grams per day of salmon oil for 16 weeks, with or without a daily multivitamin, significantly reduced F2-isoprostane levels, but did not affect markers of inflammation in healthy adults.
F2-isoprostanes are lipid peroxidation products and are considered the most reliable biomarkers of in vivo lipid peroxidative damage, explained the researchers.
“Relative to placebo, both the 6 g salmon oil and the 6 g salmon oil multivitamin groups reduced plasma F2-isoprostane levels at study endpoint,” wrote the authors, led by Andrew Pipingas from the Swinburne University of Technology. “This suggests that intake of LC n-3 PUFA can reduce oxidative stress, regardless of concomitant vitamin and mineral intake.
“Interestingly, 3 g of daily salmon oil combined with a multivitamin had no effect on F2-isoprostane levels suggesting that salmon oil dosage is an important factor in initiating an antioxidant effect.”
“To the best of our knowledge, this is the first RCT to investigate the combined effects of fish oils and multivitamins on human health,” explained the researchers. Data from the trial relating to cognitive and cardiovascular health have already been published (Pase et al., Journal of the American College of Nutrition, and Pipingas et al., Nutrients), but the new paper looks at secondary outcomes, including measures of inflammation, oxidative stress, serum lipids and liver function, they said.
Pipingas and his co-workers recruited 160 healthy adults with an average age of 59.3 to participate in their 16 week double-blind, randomized controlled trial. Participants were randomly assigned to one of four groups: placebo, 3 grams of salmon oil with a multivitamin, 6 grams of salmon oil with a multivitamin, or 6 grams of salmon oil (providing 480 mg EPA and 480 mg DHA per day). The study used the commercial products Swisse Ultiboost Wild Salmon Oil and Swisse Ultivite 50 + (Men's and Women's multivitamin formulations). The study was sponsored by Swisse Wellness Pty Ltd.
Results showed that, compared to placebo, both high dose salmon oil groups displayed significantly lower F2-isoprostane levels at the end of the 16 weeks, but no such improvements were seen in the three grams of salmon oil group.
In additional, the reductions in F2-isoprostanes were correlated with increases in red blood cell PUFA levels, said the researchers.
Additional results from the same study published in the Journal of the American College of Nutrition indicated that the group receiving 6 g salmon oil alone displayed improvements in aortic blood pressure and aortic stiffness.
“This is perhaps the first study to show that supplementation with salmon oil can reduce oxidative stress in healthy subjects,” they concluded.
Source: Journal of Functional Food
Published online ahead of print, doi:
“Fish oil and multivitamin supplementation reduces oxidative stress but not inflammation in healthy older adults: A randomised controlled trial”
Authors: A. Pipingas, A. Sinclair, K.D. Croft, et al.