Can the Fat in Your Diet Affect Your Arthritis?

TL;DR:
• Higher omega-3 and lower omega-6 levels are linked with less joint inflammation.
• Trials show omega-3s can reduce pain and improve function in arthritis.
• Works best alongside movement, healthy weight, and anti-inflammatory diet.

A study that appeared in the journal Osteoarthritis Cartilage (Vol. 20, Issue 5, Pages 382-387) measured inflammation in the joints of arthritis patients averaging 60 years of age by measuring synovial thickening and cartilage damage on contrast-enhanced MRI. The researchers found that the amount of inflammation was proportional to the amount of omega 6 and omega 3 fatty acids circulating in the blood. They found that the amount of inflammation was inversely proportional levels of circulating omega-3 fatty acids and directly proportional to omega-6 fatty acid levels. In other words, more omega-3 fatty acid and less omega-6 fatty acid equals less inflammation.

But since that study, more evidence has emerged:

A recent meta-analysis pooling data from 9 randomized controlled trials (involving ~2,070 patients with osteoarthritis) found that omega-3 supplementation significantly reduced pain and improved joint function compared to placebo [1].
Other meta-analyses show that adding omega-3s is generally safe and provides modest benefit for symptoms like pain and stiffness in osteoarthritis patients [2].
In a trial of overweight/obese older adults, fish oil supplementation meaningfully reduced OA-specific pain and disease burden compared with no fish oil [3].
At the cellular level and in cartilage explant models, EPA (an omega-3 fatty acid) was shown to protect cartilage under mechanical stress and blunt inflammatory gene responses [3]