A new study out of Duke University (Durham, NC) reported that mice consuming a supplement of omega-3 fatty acids had healthier joints than those fed diets high in saturated fats and omega-6 fatty acids.
Duke Medicine researchers published in the Annals of the Rheumatic Diseases that unhealthy dietary fats – not just obesity – may contribute to worsening osteoarthritis.
“Our results suggest that dietary factors play a more significant role than mechanical factors in the link between obesity and osteoarthritis,” said Farshid Guilak, PhD, Laszlo Ormandy professor of orthopedic surgery at Duke and one of the study’s senior authors.
Obesity is one of the primary risk factors for osteoarthritis, although the mechanisms linking these conditions are not fully understood. It has been assumed that increased weight wears the joints out, but this doesn’t explain why arthritis is also found in hands and other joints that don’t bear weight, according to the study.
Guilak and his colleagues began studying systemic factors other than body weight to determine their effect on arthritis, and in an earlier study in obese mice, found that the lack of appetite hormone leptin predicted whether the mice had arthritis. “This made us think that maybe it’s not how much weight you gain, but what you eat,” Guilak said.
Omega-3 fatty acids, commonly found in fish or fish oil supplements, are often touted as “healthy fat” given their heart-healthy and anti-inflammatory properties. Unfortunately, most Americans eat significantly more saturated fat and omega-6 fatty acids than omega-3 fatty acids, reported the study.
“A healthy diet would include roughly equal ratios of these fats, but we’re way off the scale in the Western diet,” Guilak said, adding researchers found arthritis was significantly associated with the mice’s diets, not with body weight. “While omega-3 fatty acids aren’t reversing the injury, they appear to slow the progression of arthritis in this group of mice.”
Chia-Lung Wu, a biomedical engineering graduate student in the Duke Orthopaedic Research Laboratories and one of the study’s lead authors, said “we found that independent of body weight, dietary fatty acids regulate ear wound healing and severity of osteoarthritis following joint injury in obese mice.”
Guilak said researchers are working to translate their findings to humans and “a great next step would be to do a clinical study to look at effect of omega-3 fatty acids post-injury.”
For more information, visit www.corporate.dukemedicine.org.