But seafood has a darker side. Some fish pose a high risks, canned tuna and salmon may contain carcinogenic chemicals because of the tin, and studies have shown that fish is raised with antibiotics too.
Fish are full of contaminants such as mercury, which is extremely toxic. Each fish absorbs the mercury of the smaller fish it has eaten. This is why the largest and oldest fish contain the most mercury.
It is advised to avoid eating shark, golden bass and swordfish as they contain high levels of mercury. The National Center for Health Research says to “check local advisories about the safety of fish caught in local lakes, rivers, and coastal areas. If no advice is available, eat no more than 6 ounces per week of locally caught fish, and do not consume any other fish during that week.”