Is shellfish as healthy as regular fish?
October 17, 2010
Is shellfish as healthy as regular fish?
Dr Pia Martin DC.CCN
In general, fish (such as baked salmon) is a very healthy food choice. All that protein. Those omega-3 fats. But is the same true for shellfish such as lobster, shrimp, or clams?
To answer that question, we turned to the Department of Agriculture’s nutrient database. The nutrient database is easy to use, and free, but you are limited to the foods and the nutrients that the agriculture department has decided to include. Also, for ease of comparison, we chose to standardize all the amounts to 3 ounces (85 grams), which is smaller than a realistic serving size for many seafood.
Omega-3s and shellfish
So what did we find? If you’re eating cold-water fish like salmon because of the omega-3s, then shellfish may not be a great substitute. 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, or about as much as a fish like flounder. A medium-size, 6-ounce serving would give you a gram of omega-3s, which isn’t bad at all.
What about protein?
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 (clams are a bit on the low side). But if you are really serious about protein, eat some octopus. It has more protein than the 10 species of fish we checked out in the nutrient database.
Cholesterol
Saturated fat has a bigger effect on our blood cholesterol levels than the cholesterol we eat. Clams, crab, mussels, and oysters—they may lower cholesterol levels a little bit, partly because they contain compounds called sterols that interfere with the absorption of cholesterol.
Calorie counting
Naturally, the calorie count goes up for anything that’s breaded and fried. Aside from that, though, most shellfish are low in calories.
Nutritional curiosities
There are some nutritional curiosities among the shellfish. Oysters are perhaps the best food source of zinc you can find. Clams contain a lot of iron and vitamin B12. And crustaceans are champion suppliers of choline, an obscure nutrient that accelerates the synthesis of acetylcholine, a neurotransmitter important in memory and muscle control.
Toxins
There are other issues with shellfish besides nutritional pros and cons. Toxins can be a problem.
About 30 cases of poisoning by marine toxins (shellfish and finfish combined) are reported each year in the United States, and it’s possible that many minor cases go unreported. A death occurs, on average, every four years. Still, getting sick from toxin-laden shellfish is a rare event. You should, though, keep an eye out for health advisories about red tides and other toxin-generating “blooms” and eat accordingly.
Allergies
People also get sick from eating shellfish because of allergies. About 2% of adult Americans are believed to have food allergies, and allergies to shellfish are among the most common. The reactions vary, but they tend to be on the severe side. There are case reports in the medical journals of shellfish causing anaphylactic shock and even a small number of deaths.
Some people are allergic to lobster, shrimp, and other crustaceans, but not to the molluscan shellfish, and the other way around. But there’s also considerable overlap. As a practical matter, people who are allergic to one type of shellfish are usually told to avoid them all.
Last but no least…. enjoy shellfish, however for more nutritional bang for the buck enjoy the following: salmon,sardines, herring, and black cod.
My best
Dr Pia
Dr Pia Martin DC CCN
ph 760 632 1134
