Omega-3 fatty acids are considered essential fatty acids: They are necessary for human health but the body cannot make them. Omega-3 fatty acids can be found in fish, such as salmon, tuna, and halibut, other seafood including algae and krill, some plants, and nut oils. Omega-3 fatty acids play a crucial role in brain function, as well as normal growth and development and it may reduce the risk of heart disease. It also reduces inflammation and may help lower risk of chronic diseases such as heart disease, cancer, and arthritis.