Nearly 70% of the earth's surface is covered by oceans. Much of the land surface is unsuitable for growing food, so seafood is a huge resource that dwarfs all the crops from farms on the land. Yet most Americans eat much less seafood than citizens of other countries. Even though we have the Great Lakes, several large coastlines, and a robust fishing industry. Much of what is caught in US waters is exported to other countries.
Nutritionists generally approve of seafood as a healthy alternative to red meats, and their high protein, low fat, and omega-3 contents can make fish and other foods from the sea an attractive option. Omega-3's are a type of fat that many doctors consider a wonder drug because of its general health benefits. But diving into the many, many species of fish and sea creatures, and the many different methods of raising or catching them is a tricky business. Some seafood is better for you than others, and some could be downright deadly.
The top five selling types of seafood in the US are shrimp, tuna, salmon, tilapia, and Alaska pollock. These foods have made their ways into America's diet and provided sometimes healthier options to the standard meat and potatoes. As with any other foods, how they are prepared makes a huge difference. Fish that is breaded and fried is little healthier than fried chicken, but to combat the "fishy" taste, this is the preferred preparation for many.
Of these five, salmon has caught on as one of the healthiest choices, because of its high levels of antioxidants and omega-3's. Tilapia has also caught on because of its price and taste. Tilapia isn't as good a choice as salmon because is omega-3 level is much lower while its (bad) omega-6 level is higher. Tuna is popular because it's one of the few fish that does well in canned products and lasts a long time. Albacore tuna is considered the best, and there are ratings out there for tuna companies that use sustainable practices. Alaska pollock is best known for McDonald's fillet of fish sandwiches. And shrimp tastes great hot or cold, fried or steamed.
There are two ways to get salmon and a lot of the other commercially sold fish: farmed or wild-caught. Farmed fish are kept in ponds or pens and fed grains to fatten them up. Wild-caught fish are caught in their native environment using sophisticated fishing equipment. In the case of salmon, wild Alaska salmon is considered the best, and farmed salmon is okay but not as good. Farmed fish are more likely to contain contaminants from the feed that they get like dioxins, PCB's, or Roundup. Fish didn't evolve to eat high grain diets, and don't develop as well in confined conditions where they can't swim properly.
For the wild-caught fish, there are two big concerns- extinction and mercury. Fish that are nearing extinction like the Bluefin Tuna are banned from fishing in many countries and it's not sustainable to eat them. Of bigger concern is mercury, which enters the oceans from a variety of sources, the most common of which is power plants. Mercury has the power to accumulate in tissues, so that larger and longer-lived fish can get higher and higher levels of it as they eat and age. Some of the worst sources for mercury contamination are sharks, swordfish, orange roughy, marlin, grouper, dolphins, whales, and king mackerel. Mercury will accumulate in human tissues as well, and is a known toxin that can cause serious health problems and death.
Some of the claims against seafood have scared people away from eating it, but again there are only a small minority of foods that are the biggest offenders. Besides the top five fish mentioned earlier, the following list of seafoods are considered good for you and generally safe to eat.
Atlantic mackerel
Catfish
Clams
Crab
Herring
Lobster
Mussels
Octopus
Oysters
Sardines
Scallops
Seaweed/Kelp
Striped Bass
Trout
I am not a seafood expert by any means, (though I was a tilapia farmer for about a month), but these are the ones that have been rated highly in a deep dive of nutrition sites. There may be more that aren't on the list. That said, there is a big caveat that applies to all seafood. How was it raised and how was it caught? The type of food that ends up on your table can vary a lot depending on what happened to the fish before it was turned into food. And since seafood tends to rot faster than other foods, the freshness of the fish is critical and should pass the smell and sliminess tests.
If seafood is farm-raised, the gold standard is indoor recirculating tanks with wastewater treatment. These types of fish farms most closely approximate the environment of the fish, and the fish are healthier. Fish that are grown in stagnant ponds or in tanks without circulation or wastewater treatment are crowded together in their own filth and are more likely to have problems. Farm-raised fish are fed processed pellets from grains and agricultural wastes, and their diet is far-removed from what they would consume in the wild. To make farm-raised salmon pink, dyes have to be added to the food. Still, because of the economies of scale, farm-raised fish are generally cheaper than wild-caught, and more prevalent in the marketplace.
For wild-caught fish, most are caught using large nets in the ocean. Some of these nets work as intended, but some cause severe damage. Dredges and bottom trawls scrape along the sea floor and disturb entire ecosystems in their pursuit of a catch. And all open-sea nets can have the harmful affect of capturing endangered and unintended species with their hauls. Dolphins, whales, and porpoises are among the worst victims of this unintended byproduct of fishing.
Eating seafood is a lot more complicated than I once thought. But fish and other sea creatures can be an important source of protein and omega-3's, and there's gotta be a healthy way to increase your seafood consumption. The best resource that I've found is Seafood Watch, which gives detailed information about all types of seafood and which ones are safest to eat. (There are 95 ratings on types of shrimp alone, 42 of which are "Avoid".)
Weight loss tip #12- Increase your seafood consumption but do your homework.
Most of our protein diet relies on just five livestock species. The oceans and lakes provide a much more diverse array of potential foods that deserve to be considered. We need to be careful not to over-fish the waters, but with proper management they can provide healthy and safe food for many generations.