Omega-3 Fatty Acids Shown to Slow Progression of Knee Osteoarthritis

In a study published in the Annals of the Rheumatic Diseases, mice that were fed diets rich in omega-3 fatty acids had healthier knee joints than those that consumed high levels of saturated fats and omega-6 fatty acids.

Researchers at Duke University in Durham, NC, said their research suggests unhealthy dietary fats may contribute to worsening osteoarthritis (OA), even if a patient is not obese as a consequence.

Currently, obesity is a primary yet poorly understood risk factor for OA. According to senior study author Farshid Guilak, PhD, and his colleagues, one link between the 2 conditions is that, as weight increases, so does the load on joint. However, those who are obese also tend to have arthritis in non-load-bearing joints.

In their earlier work, the researchers found obese mice that lacked significant levels of the appetite hormone known as leptin were more likely to have arthritis. For their current study, they induced knee osteoarthritis (KOA) by injuring the mice’s knee joints, noting that trauma or injury accounts for 10-15% of all cases of KOA in humans.

The investigators randomized the mice to a diet rich in saturated fats, which is likely to raise cholesterol levels; a diet rich in omega-6 fatty acids, which is considered to be healthier than saturated fats; or a diet rich in omega 6-fatty acids and supplemented with omega-3 fatty acids, which are usually found in fish and deemed heart healthy and anti-inflammatory. According to the authors, most Americans eat significantly more saturated fat and omega-6 fatty acids than omega-3 fatty acids, despite recommendations to include roughly equal amounts of those fats.

The results of the study showed that diet significantly influenced arthritis, whereas body weight did not. While KOA worsened in mice that consumed diets high in saturated fat or omega-6 fatty acids, adding a small supplement of omega-3 fatty acids appeared to slow disease progression. Additionally, wound healing was accelerated in mice that consumed omega-3 fatty acids.

“Our results suggest that dietary factors play a more significant role than mechanical factors in the link between obesity and osteoarthritis,” Guilak noted in a statement.

The researchers said they are working to translate their findings to humans.