The new study was published last week in the American Journal of Clinical Nutrition. It was the work of a team of researchers from Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) with additional input from experts associated with hospitals and universities in Adelaide.
Large scale, long term
The researchers recruited 235 adults diagnosed with mild to moderate knee osteoarthritis for their six-month-long, double blind, placebo controlled trial. The subjects were all suffering mild to moderate knee pain, and were consuming little to none in the way of omega-3 supplements.
The study excluded subjects who were suffering conditions such as rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis and other similar conditions. The participants ranged in age from 40 to 65 and ranged from the very lean (BMI of 18) to those verging on morbidly obese (BMI of 35), with the average about 28 BMI for the men. That put the study population on the high end of what health authorities consider to be a healthy weight.
The participants were about evenly divided between men and women. Some of the subjects used pain relief medications during the trial (NSAIDs), but as these were mostly used on an as-needed basis, the researchers chose to assess this via a post study questionnaire.
Study used Aker material
The investigational material was a high potency krill oil product made by Australian supplement manufacturer Swisse that provided 150 mg of DHA and 70 mg of EPA in each 1 gram capsule as well as a certain amount of astaxanthin. The raw material is the Superba Boost brand of krill oil supplied by Norwegian firm Aker BioMarine. The study called for subjects to take 4 capsules every day of the Swisse product, which meant that subjects were ingesting 600 mg of DHA and 280 mg of EPA per day in phospholipid form.
The primary outcome was the change in knee pain as measured on the well-validated WOMAC score. The researchers also assessed knee joint stiffness and did blood analyses that measured lipid profiles.
Krill oil intervention cut knee pain
The study found that the krill oil intervention significantly reduced knee pain as well as improving knee joint stiffness and function. The study also found that the krill oil boosted the Omega-3 Index of the participants up to an average of 9% by study’s end. Most experts consider an 8% level to be the threshold for deriving the greatest health benefits from omega-3s.
“This clinical trial represents the largest, longest, and highest dose study to date investigating the effects of krill oil on osteoarthritis of the knee,” said principal author Dr Welma Stonehouse, PhD, who is a CSIRO principal research scientist.
The latest research is part of an ongoing research effort put in place by Aker BioMarine, said Thomas B. Repstad, Aker’s global technical marketing manager. Earlier research had hinted at these effects, but the statistical power and length of this latest study strengthens the message, he said.
“While we are not entirely surprised by the results, this study definitely solidifies the effect of krill oil on joint health,” Repstad said.
Aker: High dosage still relevant to marketplace
One issue with the research of krill oil that has cropped up over the years is that krill oil supplement marketers have often capitalized on the purported greater bioavailability of the material vis a vis fish oils to tell consumers that less is better, and one small pill is enough versus the several large softgels that fish oil use can call for. Yet this study, like some other krill oil research, was done on higher dosages. In this case subjects were asked to ingest four capsules per day.
“Different populations have different needs when it comes to nutrients, and this is no different for krill oil. For the majority of healthy people, one or two small capsules of krill oil deliver adequate amounts of omega-3 and choline to support healthy levels of these nutrients. However, when it comes to people with conditions such as mild OA, more of these nutrients may be needed to see beneficial effects. Furthermore, if you take 1-2 capsules over the long term, this may be enough to maintain healthy joints, however to see an effect in a study over a relatively short time (i.e., months), it may be necessary to increase the dose,” Repstad said.
Source: The American Journal of Clinical Nutrition
Krill oil improved osteoarthritic knee pain in adults with mild to moderate knee osteoarthritis: a 6-month multicenter, randomized, double-blind, placebo-controlled trial
Authors: Stonehouse W, et al.