Omega-3 fatty acids: These "good" fats are found in many nuts, especially walnuts and almonds. They contain alpha-linolenic acid (ALA), a type of omega-3 found in plants. Omega-3s may help lower the risk of heart disease, depression, dementia, and arthritis. They can also help your heart by reducing inflammation, lowering triglycerides, and slowing plaque buildup in blood vessels.