Omega-3 fatty acid supplements don’t appear to have any benefit on multiple sclerosis (MS), according a study by Norwegian researchers. Multiple sclerosis affects about 2.5 million people worldwide. Some prior research has indicated that omega-3 fatty acid supplements might have anti-inflammatory effects that could benefit those with the disease, according to background information in the study. Omega-3 fatty acids are found in cold-water fish, such as salmon, and in fish oil supplements.