A recent longitudinal study - composed of over 14,000 women and 13,000 of their children up to age 12 followed since 1991 - showed that the benefits of eating fish high in omega-3 fats far outweighed the risk of consuming mercury in the fish. The children of mothers who ate more fish had higher IQs and better social interactions.
What's going on? Who's to blame for this confusion? And most importantly, what should you do when it comes to seafood consumption?
The results of this well-designed study are in sharp contrast to prior recommendations from the U.S. government to limit weekly consumption of fish by pregnant women. This was the result of increasing concerns over the damaging effects of mercury in the fish. But as with many other nutrition topics, the right course of action is often more complex than avoiding entire categories of foods that sometimes contain something bad. Further, very little guidance is given on which species of fish are the most beneficial or risky.
100 years ago there was no such thing as a mercury problem in seafood. Then governments began allowing companies to dump various wastes into lakes, rivers, and streams, thus polluting the water with mercury.
The mercury concentrates in smaller species which are eating by larger species. So, the larger up the food chain you go, the higher the typical concentrations of mercury you will find. So, we are to blame for the polluted waters that create polluted fish. Let's not be mad at the fish.
What should you do?
- Eat seafood that is higher in omega-3 fats and lower in mercury. (view table from the Washington Post)
- When possible, choose wild fish vs. farmed fish (farmed fish are often raised in pens located in lakes or near river outlets and are thus subject to higher concentrations of waste and sewage from dumping). Yes, the difference matters.
- Support environmental legislation requiring the clean-up of our waterways and restricting future dumping of wastes into our waterways.
