Omega-3 supplements may help prevent dementia and Alzheimer’s; Click here for DetailsAlzheimer’s alone accounts for approximately 60–70% of all dementia cases. In this context, a recent study showed that omega-3 fatty acids, found in fish and fish oil supplements, may be beneficial for brain health and reduce the risk of diseases like Alzheimer's. Supplements: Fish oil capsules, cod liver oil, or algae-based supplements for vegetarians. How does fish oil help? Experts believe that taking fish oil in the early stages may be more beneficial.