The study, published in the journal Osteoarthritis and Cartilage, claims to be the first to confirm the supposed benefits of omega-3 fatty acids for joint health in an animal model – finding that an omega-3-rich diet fed to guinea pigs that naturally develop osteoarthritis, reduced disease by 50% compared to a standard control diet.
The authors of the research, from the University of Bristol in the UK, said the findings are a major step forward, showing that omega-3 fatty acids – sourced from either fish oil or flax oil – could help to slow down the progression of osteoarthritis, or even prevent it occurring.
“This study demonstrates clear benefits of omega-3 supplementation in reducing the signs of osteoarthritis in a naturally occurring model of disease,” said the Bristol based researchers, who were led by Dr John Tarlton.
“Furthermore, there was no sign that increased omega-3 would lead to disease in the osteoarthritis free strain,” they added.
Tarlton explained that classic early signs of (OA), such as the breaking down of collagen in cartilage and the loss of molecules that give it shock-absorbing properties, were both reduced with an omega-3 rich diet.
"There was [also] strong evidence that omega-3 influences the biochemistry of the disease, and therefore not only helps prevent disease, but also slows its progression, potentially controlling established osteoarthritis," he said.
Professor Alan Silman, medical research director of Arthritis Research UK – who funded the research – explained that research in dogs has previously suggested that scientists were a long way away from understanding the potential uses of omega-3 in human osteoarthritis.
“However, this current research in guinea pigs is exciting as it brings us closer to understanding how omega-3 might fundamentally interfere with the osteoarthritis process, and that it could potentially be taken as a treatment," he said.
Osteoarthritis is caused when the cartilage at the ends of bones wears away and the underlying bone thickens, leading to stiff, painful joints. Currently, there is no effective treatment to slow down disease progression, and treatment is limited to pain relief and ultimately joint replacement.
The authors noted that in an ageing population, the disease is set to become the fourth leading cause of disability by 2020, “so with the current lack of effective treatments there is an urgent need for preventative measures.”
They added that modern ‘Western’ diets low in omega-3 have been linked with increases in inflammatory disorders, including OA, and noted that omega-3 is also thought to increases bone density – a possible contributing factor in OA.
Tarlton and his team explained that guinea pigs prone to naturally develop OA were compared with an OA-resistant strain each fed a standard or an omega-3 rich diet from 10 to 30 weeks.
They found that dietary omega-3 reduced disease in OA-prone animals, with most disease markers modified towards those of the non-OA prone strain – though not all significantly so.
Tarlton said that further studies are needed to determine the influence of omega-3 fatty acids on the established disease in guinea pigs, and to confirm the effects in human osteoarthritis.
"The only way of being certain that the effects of omega-3 are as applicable to humans as demonstrated in guinea pigs is to apply omega-3 to humans. However, osteoarthritis in guinea pigs is perhaps the most appropriate model for spontaneous, naturally occurring osteoarthritis, and all of the evidence supports the use of omega-3 in human disease," he added.
Source: Osteoarthritis and Cartilage
Volume 19, Issue 9, Pages 1150-1157, doi: doi:10.1016/j.joca.2011.06.005
“Regulation of osteoarthritis by omega-3 (n-3) polyunsaturated fatty acids in a naturally occurring model of disease”
Authors: L. Knott, N.C. Avery, A.P. Hollander, J.F. Tarlton