Mussels have both health benefits and some downsides- but I think there’s a lot of confusion about both. On the plus side, mussels are a lean source of protein and rich in essential vitamins and minerals- mostly iron, Vitamin B12, selenium, iodine, and phosphorus.  Compared with shrimp, they are low in dietary cholesterol too. They also are a source of Omega 3 fatty acids, which are important for heart health. Unfortunately, mussels are prone to water pollution contamination, and mussels sourced from not properly monitored areas can carry serious toxins. The good news is that boiling or steaming them greatly mitigates these risks, as well as buying from a reputable source.