The government says people gain more from eating seafood than they risk by possibly consuming contaminants like mercury.
Even so, a new report from the Institute of Medicine says regulators need to help consumers figure out which seafood is safer.
A Tufts University researcher, who participated in the study, says confusion "may have scared people out of eating something that is beneficial for them."
But critics of the report say it should have listed "good fish" and "bad fish", something the researchers said would be too hard.
The findings underscore the conclusion that eating fish and shellfish may reduce the risk of heart disease. Evidence suggests that seafood rich in omega-three's may even help newborns and expectant moms.