Fish has long been praised as one of the healthiest protein sources in the world . It is a cornerstone of heart - healthy diets around the world since it is loaded with vitamins, minerals, and omega - 3 fatty acids . However, not all fish are made alike; some are known for their high nutritional content and low mercury levels . The five healthiest fish choices that you can enjoy without feeling guilty are listed below , along with their justification for being on your dish . 1. Salmon • The reasons why it ' s nutritious : High levels of vitamin D, omega-3 fatty acids, and antioxidants like selenium. • Advantages : Enhances cognitive function , lowers inflammation, and supports cardiovascular health . • Expert tip: For the cleanest option with...