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If you’re at all interested in healthy eating, you’ve more than likely heard about the benefits of eating fish.  Salmon and other cold-water fish have been highlighted for their healthy fats and high protein sources. Of course, it’s important to note that the bigger the fish, the more toxicity it can contain but generally speaking, adding an average of three servings of fish weekly is a sure way to increase your nutrition.

But what about shellfish?  Are shrimp, mussels, and crab just as healthy?

Let’s compare, ounce per ounce the nutrition in both of these pescatarian options.  To make it fair, we’re comparing 3.5-ounce servings according to the Department of Agriculture’s food database.


Omega 3s

Omega 3 is an essential fat that our body cannot produce on its own.  It needs to be supplied to the body through food. When it comes to fish, wild-caught salmon is one of the top foods in supporting the entire body.  One of the main reasons results from salmon’s omega-3 fatty acids. Boasting more than 1.75 g per serving, salmon helps to reduce inflammation in the body, supports your bones and mental health.

Now, comparing salmon to shellfish, we fall short.  Shellfish is not a great substitute for omega 3s. Lobster contains very few omega-3s, and shrimp and clams are pretty modest contributors. Calamari, blue crab, and oysters have about a fourth of the omega-3 content of salmon.  If you plan on eating more shellfish than salmon, you may want to include more omega 3 rich foods to your diet. Flax and chia seeds are a great choice.

Lemon Salmon Salad



If you’re looking for protein, then you’ll do all right at the clam shack or lobster bake. Ounce for ounce, they’re pretty much in the same neighborhood as salmon. But, if you are really serious about protein, eat some octopus. One serving has over 29g of protein.  Tuna is a close match but with its large size, we believe it to be more toxic to the body due to its high levels of mercury.



Saturated fat has a bigger effect on our blood cholesterol levels than the cholesterol we eat. In fact, about 80% of our body’s cholesterol is manufactured by the liver.  However, some people are considered to be “cholesterol responders” — meaning that the amount of cholesterol they eat greatly impacts their blood cholesterol levels. All fish contain some cholesterol. But don’t let that scare you. Different kinds of seafood contain different amounts of cholesterol and may contain fats that can actually help you manage your cholesterol levels.  But if you’re watching what your intake of cholesterol is, a steady diet of shrimp might be a problem. One serving has 194 mg of cholesterol which is considered to be quite high. Other shellfish like clams, crab, mussels, and oysters are better choices and may lower cholesterol levels because they contain compounds called sterols that interfere with the absorption of cholesterol.  

Fresh fish is also a great choice if you are trying to keep your dietary cholesterol low.  Salmon and tilapia are amongst the lowest, with only 50mg of cholesterol per serving.



There are some who can get very sick from eating shellfish or fish because of allergies. An allergy, in general, is an abnormal response by the body’s immune system to proteins in certain foods.  About 2% of adult Americans are believed to have food allergies, and allergies to shellfish are among the most common. Shellfish can include shrimp, crab, oysters, lobster as well as squid and scallops.  Some people are allergic to lobster and shrimp but not clams or mussels. For others, it’s the opposite. The reactions vary, but they tend to be on the severe side. As a practical matter, people who are allergic to one type of shellfish are usually told to avoid them all.

Regarding fish,  it is possible to experience allergies also.  One can react to different species of fish, including fresh and saltwater fish, and not others and this varies from person to person.  Interestingly, people who are allergic to fish may not need to avoid fish oil supplements. Fish oils supplements tend to be refined enough to remove all of the proteins that can trigger allergic reactions. However, you should always consult your allergist before consuming anything made with fish oils.



There are other things to consider about shellfish and fish besides nutritional pros and cons. Toxins can be a problem.  There are a few different toxins to consider, like a red-tide toxin, but the one of most concern is mercury. Just like human bodies, fish store ingested mercury within their cells and tissues. Within smaller fish and seafood, this is less of a concern. However, with larger, predatory fish, mercury levels accumulate too much higher levels.  Plus, up to 95% of the mercury, we ingest from the fish we eat is readily absorbed into our bloodstream, cells, and organs. It can be stored in our bodies for many years.

How many servings per week?  This is always dependant on current health levels.  Seafood and fish are excellent sources of high-quality protein, omega 3s, and iron. This is why it is recommended to eat at least two servings of fish a week. However, women who may become pregnant or are already pregnant, nursing mothers and young children need to be more careful. The FDA advises pregnant or nursing women to avoid four fish that contain high levels of mercury: shark, swordfish, king mackerel, and tilefish. Instead, they should eat up to 12 ounces a week of fish and shellfish that are lower in mercury. These include shrimp, canned light tuna, salmon, Pollock, and catfish. If you eat canned albacore (“white”) tuna, limit your intake to 6 ounces per week because it has higher mercury content. Young children should eat smaller portions of these fish.

In conclusion, shellfish and fish are healthy.  They offer you so many beneficial nutrients and depending on your needs, can really support your health.  Including a minimum of one serving per week can promote heart health, fight off depression, boost your brain power and improve your eyesight.

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